01891nas a2200169 4500008004100000022001400041245012200055210006900177260007100246300001400317490000800331520118500339100002401524700002601548700001601574856013101590 2009 eng d a1932-744700aDensity functional investigation of relativistic effects on the structure and reactivity of tetrahedral gold clusters0 aDensity functional investigation of relativistic effects on the  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR a7101-71060 v1133 a

The influence of relativistic effects on the structure, vibrational modes, and reactivity of recently discovered tertrahedral gold clusters (Au(19) and Au(20)) are investigated using density functional methods. The intramolecular reactivity of the clusters was analyzed using density functional-based reactivity descriptors. The work shows that whereas the structural properties and vibrational modes are considerably affected by the relativistic effects, the reactivity trends based on Fukui function calculation on various atoms within this cluster remain unaffected by the absence or presence of relativistic effects. The reactivity descriptors reveal that the vertex atoms are the most reactive ones in Au(20) toward a nucleophilic attack. On the other hand, atoms connecting the missing vertex edge with the pyramid base along with the vertex atom are the most reactive for a nucleophilic attack in Au(19). The atoms lying at the center of each face are favorable for an electrophilic attack in both cases. Interestingly, the atoms with a missing cap in Aulg are highly favorable for electrophilic attack, and Au(20) has more sites for a favorable nucleophilic attack.

1 aDe, Himadri, Sekhar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/density-functional-investigation-relativistic-effects-structure-and-reactivity-tetrahedral-001449nas a2200169 4500008004100000022001400041245013200055210006900187260007300256300001200329490000800341520073500349100002501084700002601109700001601135856012801151 2010 eng d a0009-261400aInfluence of plane wave cut-off on structural and electronic properties in Sn-BEA and Ti-BEA zeolite water molecule interaction0 aInfluence of plane wave cutoff on structural and electronic prop aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a374-3790 v4843 a

Periodic systems are best described by the pseudo-potential methods. However, the accuracy of its description depends on the cut-off of plane wave basis. This is much more critical in the case of weak interactions, where a clear understanding on the influence of plane wave cut-off on the structural and electronic properties is not readily available in the literature. In the present work, we have taken a metal substituted beta zeolite-H2O complex for understanding this objective. Our studies show that while a lower cut-off of 500 eV is sufficient for the convergence of the structural parameters, description of energy-dependent properties necessitates a high cut-off value. (C) 2009 Elsevier B.V. All rights reserved.

1 aKulkarni, Bhakti, S.1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/influence-plane-wave-cut-structural-and-electronic-properties-sn-bea-and-ti-bea-zeolite-002925nas a2200229 4500008004100000022001400041245014300055210006900198260007300267300001000340490000800350520203500358653001702393653001802410653002702428653001702455653002702472100002502499700002602524700001602550856012902566 2010 eng d a1381-116900aProbing lewis acidity and reactivity of Sn- and Ti-beta zeolite using industrially important moieties: a periodic density functional study0 aProbing lewis acidity and reactivity of Sn and Tibeta zeolite us aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG a36-430 v3293 a

The Lewis acidic nature and reactivity of two industrially important catalysts, viz.. Sn and Ti substituted beta zeolite (T-BEA) are analyzed using a unique combination of structural parameters, energetics and reactivity descriptors. To achieve this purpose, we adsorb the industrially important moieties (L) namely NH(3), H(2)O, CH(3)OH, CH(3)CN on the active sites of T-BEA. The calculations were performed using a periodic density functional method where the valence electrons are described using a plane wave basis set in conjunction with pseudo-potentials for the core electrons. The analysis of the structural properties of these complexes reveals that TO(4) shows typical characteristic splitting 120 degrees/90 degrees, close to bipyramidal geometry as compared to tetrahedral symmetry observed in the bare T-BEA. This is associated with small variations in the framework bond lengths (>= 0.08 angstrom) and a substantially large variation of bond angles (<= 10 degrees) in all the ligand-zeolite complexes. Further in both cases of Sn and Ti substituted beta zeolite, ligand interacts at optimum inter-atomic bond distance. Our interaction energies show that adsorption of all ligand moieties is stronger at Sn center than that of Ti. In general, the order of stability of the different T-BEA adducts is NH(3) > H(2)O > CH(3)OH > CH(3)CN. The ligand interaction is associated with the corresponding bond elongation and bond reduction of the adsorbed molecules on catalyst active site, which can be taken as measure of red or blue shifted frequencies. Finally, the global descriptors of reactivity justify the fact that soft acid, Sn-BEA, interacts strongly with soft bases following the Pearson's HSAB principle. However, hard acid, Ti-BEA interacts with soft bases to form a stable Lewis adduct. Furthermore, the HOMO-LUMO gap of all Sn-BEA-L adducts is lower than that of Ti-BEA-L adducts indicating to its higher Lewis acidic nature compared to Ti-BEA. (C) 2010 Elsevier B.V. All rights reserved.

10aBeta zeolite10aLewis acidity10aLigand-zeolite complex10aPeriodic-DFT10aReactivity descriptors1 aKulkarni, Bhakti, S.1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/probing-lewis-acidity-and-reactivity-sn-and-ti-beta-zeolite-using-industrially-important-000819nas a2200169 4500008004100000022001400041245013700055210006900192260007100261300001400332490000800346520014600354100002400500700002600524700001600550856008300566 2010 eng d a1932-744700aUnderstanding the reactivity properties of Au-n (6 <= n <= 13) clusters using density functional theory based reactivity descriptors0 aUnderstanding the reactivity properties of Aun 6 n 13 clusters u a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR a6690-67030 v1143 a

{Relativistic density functional theory (DFT) based calculations have been performed on gold clusters with six to thirteen atoms (Au-n

1 aDe, Himadri, Sekhar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/understanding-reactivity-properties-au-n-6-000843nas a2200181 4500008004100000022001400041245011600055210006900171260007100240300001600311490000800327520014800335100002400483700002600507700001900533700001600552856009300568 2011 eng d a1932-744700aFinite temperature behavior of gas phase neutral Au-n (3 <= n <= 10) clusters: a first principles investigation0 aFinite temperature behavior of gas phase neutral Aun 3 n 10 clus a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a17278-172850 v1153 a

{Relativistic density functional theory (DFT) based molecular dynamical simulations are performed on gold clusters with 3-10 atoms (Au-n

1 aDe, Himadri, Sekhar1 aKrishnamurty, Sailaja1 aMishra, Deepti1 aPal, Sourav uhttp://library.ncl.res.in/content/finite-temperature-behavior-gas-phase-neutral-au-n-3-001980nas a2200169 4500008004100000022001400041245014900055210006900204260007100273300001600344490000800360520124700368100002501615700002601640700001601666856012801682 2011 eng d a1932-744700aSize- and shape-sensitive reactivity behavior of Al-n(n=2-5, 13, 30, and 100) clusters toward the N-2 molecule: a first-principles investigation0 aSize and shapesensitive reactivity behavior of Alnn25 13 30 and  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG a14615-146230 v1153 a

Reactivity of aluminum clusters has been found to exhibit size-sensitive variations. N-2 reduction is a hard process, and its dissociation on the Al surface is one of the few chemical methods available under nonhazardous conditions. In this context, we attempt to understand the adsorption behavior of N-2 molecules as a function of varying size and shape of Al clusters using a Density Functional Theory (DFT) based method. During the complex formation, various N-2 adsorption modes are examined. The results clearly demonstrate that, while the interaction energy does not vary with respect to the cluster size, shape of the cluster is highly contributive toward the chemisorption (a prerequisite for the reactivity) of the N-2 molecule. The underlying electronic and structural factors influencing the adsorption of N-2 molecules on the Al clusters are analyzed with the help of the Electron Localization Function (ELF) and Frontier Molecular Orbitals. As an illustration, the activation barrier calculations on various Al-13 conformations are calculated, and results confirm the experimental propositions that high-energy structures (depending upon their geometrical and electronic orientation) are more favorable for N-2 reduction.

1 aKulkarni, Bhakti, S.1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/size-and-shape-sensitive-reactivity-behavior-al-nn2-5-13-30-and-100-clusters-toward-n-2-002600nas a2200217 4500008004100000022001400041245011400055210006900169260009200238300001200330490000700342520176600349653000802115653000902123653002802132653003302160100001902193700001602212700002602228856012802254 2011 eng d a0892-702200aUnderstanding the molecular conformations of Na-dimyristoylphosphatidylglycerol (DMPG) using DFT-based method0 aUnderstanding the molecular conformations of Nadimyristoylphosph a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcAUG a953-9630 v373 a

The molecular conformations of phospholipids comprising a lipid bilayer determine the physico-chemical properties of the latter. In this study, we attempt to understand the various possible conformations available for an anionic lipid molecule dimyristoylphosphatidylglycerol (DMPG) with Na as its charge-compensating cation. The various possible molecular orientations available for lipid molecule are analysed using a density functional theory-based method. Our study reveals a rich conformational space with two different types of glycerol body orientations, more commonly known as rotamers. Interestingly, this is in agreement with the molecular conformations proposed earlier by NMR studies on lipid monomer solutions. We demonstrate that these conformations are an outcome of delicate balance of electrostatic and van der Waals forces along with intra-molecular hydrogen bonds achieved by a critical combination of torsion angles. Na(+) ions are seen to interact predominantly with the oxygen atoms of the glycerol groups in tail and head along with that of phosphate oxygen atoms leading to a cage-like orientation of lipid molecule around the Na(+). Following the conformational analysis, we attempt to evaluate the electronic properties of few low-lying conformations. This study shows that though the water molecules screen the Na-O(lipid) interactions, they do not dramatically modify the Na-O(lipid) bond distances. The lipid conformation retains the cage-like structure around the Na(+) in the presence of water molecules. Some amount of charge transfer from the water molecules to Na ion is noted. The water molecules modify the phosphate-tail glycerol group interactions leading to a more stable Na-DMPG-H(2)O and Na-DMPG-4H(2)O complexes.

10aDFT10aDMPG10amolecular conformations10arotamer and hydration energy1 aMishra, Deepti1 aPal, Sourav1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/understanding-molecular-conformations-na-dimyristoylphosphatidylglycerol-dmpg-using-dft-001858nas a2200229 4500008004100000022001400041245010400055210006900159260007300228300001200301490000800313520098400321653001801305653004001323653003001363653002201393653002501415100002401440700002601464700001601490856012201506 2012 eng d a0920-586100aFirst principle investigation on the thermal stability of a golden fullerene: a case study of Au-320 aFirst principle investigation on the thermal stability of a gold aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC a106-1090 v1983 a

Structural and electronic properties of Au-32 cluster are analyzed using relativistic density functional theory (DFT) based methods. Further, DFT based molecular dynamical (MD) simulations are performed on Au-32 golden fullerene with an aim of understanding its thermal stability at various working temperatures. Various conformations being populated at different temperatures of a cluster are analyzed. The study shows that the ground state icosahedral conformation is stable only up to 300 K and structure remains in a hollow conformation only up to 400 K. This clearly explains the reasons for failure by experimentalists in trapping the unique fullerene conformation in spite of the theoretical predictions of it being a very stable one. The above MD study also indicates that the bare fullerene Au-32 cluster (without any stabilizing ligands) can be used for potential catalytic applications only around room temperatures. (C) 2012 Elsevier B. V. All rights reserved.

10aAu-32 cluster10aBorn-Oppenheimer molecular dynamics10aDensity functional theory10aGolden fullerenes10aRelativistic effects1 aDe, Himadri, Sekhar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/first-principle-investigation-thermal-stability-golden-fullerene-case-study-au-32-002343nas a2200169 4500008004100000022001400041245011700055210006900172260007100241300001600312490000800328520165200336100001701988700001602005700002602021856012602047 2013 eng d a1932-744700aInfluence of charge and ligand on the finite temperature behavior of gold clusters: a BOMD study on Au-6 cluster0 aInfluence of charge and ligand on the finite temperature behavio a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a20982-209900 v1173 a

Conformation and electronic charge on a gold cluster are known to determine its catalytic property. However, little is known on the finite temperature behavior of various gold cluster conformations. Much less is known on the role of charge or a ligand in stabilizing a conformation at finite temperatures. In this work, we have carried out relativistic density functional theory (DFT) based molecular dynamical simulations on neutral and charged Au-6 clusters with an aim of understanding the stability of ground state conformations as a function of charge on the cluster. Our simulations reveal that cationic and anionic Au-6 clusters undergo conformational transitions at 500 K where as neutral Au-6 cluster retains its ground state conformation up to a temperature of 1100 K. In order to look into the factors leading to the stabilization of neutral Au-6 cluster (or destabilization of cationic and anionic Au-6 clusters), structural and electronic properties are analyzed. Factors such as charge redistribution within the atoms and composition of molecular orbitals are seen to contribute towards stronger Au-Au bonds in Au-6(0) thereby stabilizing it considerably. Following the analysis, simulations are also extended to neutral, cationic, and anionic Au-6-COn (n = 1,2) complexes. In the case of CO chemisorbed Au-6 clusters, neutral and negatively charged ground state conformations are stable up to nearly 800 K, while the positively charged Au-6 ground state conformation collapses at room temperature. This work, in short demonstrates how charge or even a ligand can be used to moderate the physical properties of a gold cluster.

1 aManzoor, Dar1 aPal, Sourav1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/influence-charge-and-ligand-finite-temperature-behavior-gold-clusters-bomd-study-au-6-001794nas a2200169 4500008004100000022001400041245021300055210006900268260007100337300001400408490000800422520102600430100001701456700001601473700002601489856010901515 2013 eng d a1089-563900aUnderstanding the site selectivity in small-sized neutral and charged AI(n) (4 <= n <= 7) clusters using density functional theory based reactivity descriptors: a validation study on water molecule adsorption0 aUnderstanding the site selectivity in smallsized neutral and cha a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a8691-87020 v1173 a

Aluminum clusters are now technologically important due to their high catalytic activity. Our present study on the small-sized aluminum clusters applies density functional theory (DFT)-based reactivity descriptors to identify potential sites for adsorption and eventual chemical reaction. Depending on symmetry, susceptibility of various type of reactive sites within a cluster toward an impending electrophilic and/or nucleophilic attack is predicted using the reactivity descriptors. In addition, the study devises general rules as to how the size, shape, and charge of the cluster influences the number of available sites for an electrophilic and/or nucleophilic attack. The predictions by reactivity descriptors are validated by performing an explicit adsorption of water molecule on Al clusters with four atoms. The adsorption studies demonstrate that the most stable water-luster complex is obtained when the molecule is adsorbed through an oxygen atom on the site with the highest relative electrophilicity.

1 aDas, Susanta1 aPal, Sourav1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/understanding-site-selectivity-small-sized-neutral-and-charged-ain-4-001940nas a2200241 4500008004100000022001400041245011400055210006900169260005700238300000900295490000800304520105600312653002401368653003601392653001101428653002401439653002101463100002101484700002201505700002601527700001601553856012901569 2014 eng d a1432-881X00aComputational investigation on the catalytic activity of Rh-6 and Rh4Ru2 clusters towards methanol activation0 aComputational investigation on the catalytic activity of Rh6 and a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcDEC a15970 v1343 a

Catalysis of molecular activation of small molecules through scission of strong chemical bonds is one of the major challenges faced by chemists. More specifically, activation of the strong C-H and O-H bonds of various alcohols, especially methanol, is one of the various important intermediate steps of key organic reactions. Our present work explores a suitable metal cluster catalyst towards methanol dissociation. In particular, we have examined the effect of ruthenium doping (Rh:Ru = 2:1) on the catalytic activity of Rh-6 cluster towards methanol dissociation. Density functional theory-based calculations illustrate two competitive pathways for methanol dissociation, which are via O-H and C-H bond breaking. Both the pathways are found to be energetically favourable in the presence of bimetallic and mono-metallic clusters. Importantly, energy barrier for O-H bond dissociation reduces considerably in doped cluster as compared to pure Rh-6 cluster and is smaller than the values reported for a number of other small metallic clusters.

10aBimetallic Clusters10aDensity Functional Theory (DFT)10aDoping10aMethanol Activation10aRhodium Clusters1 aGhatak, Kamalika1 aSengupta, Turbasu1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/computational-investigation-catalytic-activity-rh-6-and-rh4ru2-clusters-towards-methanol-002011nas a2200169 4500008004100000022001400041245007600055210006900131260007100200300001600271490000800287520137800295100001701673700001601690700002601706856010901732 2014 eng d a1932-744700aDinitrogen activation by silicon and phosphorus doped aluminum clusters0 aDinitrogen activation by silicon and phosphorus doped aluminum c a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG a19869-198780 v1183 a

N-2 reduction is crucial for life, and very few catalysts are currently available to carry out this process at ambient temperature and pressure. In the present work, density functional theory based calculations reveal doped aluminum clusters to be highly reactive toward molecular nitrogen and hence are prospective materials for its activation at low temperatures. Calculations on silicon and phosphorus doped aluminum clusters with 5-8 atoms demonstrate an enhanced N-2 activation with respect to their pristine ground state and high energy counterparts. This increased efficiency of N-2 activation by doped ground state Al clusters is corroborated by an increment of the N N bond length, a red shift in N N bond stretching frequency, and adsorption energy (E-ad). Ab initio molecular-dynamics simulations demonstrate consequential efficiency of doped clusters toward dinitrogen activation at finite temperature. The ability of doped clusters toward activation of molecular nitrogen is site and shape sensitive. In short, this theoretical study highlights the critical role of doping foreign impurities for future endeavors in the design of cost-effective and efficient catalysts for N-2 activation at ambient temperatures. This observation may spur further studies in the field of aluminum nanocatalysis by doping silicon and phosphorus atom in aluminum clusters.

1 aDas, Susanta1 aPal, Sourav1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/dinitrogen-activation-silicon-and-phosphorus-doped-aluminum-clusters-002005nas a2200169 4500008004100000022001400041245008700055210006900142260000900211300001400220490000800234520142600242100001701668700002601685700001601711856010801727 2014 eng d a1932-744700aEffect of silicon doping on the reactivity and catalytic activity of gold clusters0 aEffect of silicon doping on the reactivity and catalytic activit cAPR  a7501-75070 v1183 a

Doping is known to be an excellent and simple way of catalyst design. Although notable progress has been made in understanding the reactivity and catalytic activity of gas-phase and supported gold clusters, very few studies have been carried out on the doped gold clusters. In the present work, we have carried out density functional theory calculations to investigate the effect of silicon doping on the reactivity and catalytic activity of gold nanoclusters. The present work particularly focuses on the adsorption and activation of molecular oxygen on the pristine and silicon-doped gold clusters. The results confirm that the silicon-doped Au7Si cluster shows considerable binding and activation of the O-2 molecule in comparison to the pristine Au-8 cluster as reflected in the relevant geometrical parameters (O-O and Au-O bond lengths) and O-O stretching frequency. However, silicon doping has no contrasting effect on the reactivity and catalytic activity of the Au-7 cluster. In addition to the stronger binding and activation of the O-2 molecule, the doped Au7Si cluster leads to a significant reduction in the activation barrier (0.57 eV) for the environmentally important CO oxidation reaction in contrast to the catalytically inactive pristine Au-8 cluster (1.22 eV). Thus, our results highlight the critical role of doping foreign impurities for future endeavors in the field of gold nanocatalysis.

1 aManzoor, Dar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/effect-silicon-doping-reactivity-and-catalytic-activity-gold-clusters01929nas a2200157 4500008004100000245016500041210006900206260000800275300001600283490000800299520127400307100001701581700002601598700001601624856013101640 2016 eng d00aContriving a catalytically active structure from an inert conformation: a density functionalinvestigation of Al, Hf, and Ge doping of Au-20 tetrahedral clusters0 aContriving a catalytically active structure from an inert confor cSEP a19636-196410 v1203 a

The transformation of an inert structure into a catalytically active conformation has immense potential from a structural engineering point of view. In the present work, we explored methods of achieving such a transformation through a density-functional-based study. Au-20 is known be one of the most stable and catalytically inert gold clusters, with a well-known tetrahedral structure. We demonstrate the transformation of the inert Au-20 conformation into a highly active catalytic cluster through selective doping with Hf and Ge atoms. Depending on the dopant, the inert tetrahedral Au-20 cluster evolves into either an endohedral or a hollow-cage-like conformation. The structural changes are manifested in the catalytic properties as well, with the result that the transformed doped cages exhibit extremely low activation barriers for the environmentally important CO oxidation reaction as compared to reported inert Au-20 cluster. The activation barriers for CO oxidation are particularly low (<0.12 eV) when germanium is directly involved in the CO oxidation. Thus, the current work highlights the importance of engineering structural properties of metal nanoclusters with the help of heteroatom dopants for future applications in efficient catalysis.

1 aManzoor, Dar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/contriving-catalytically-active-structure-inert-conformation-density-functionalinvestigation03074nas a2200265 4500008004100000022001400041245008500055210006900140260009200209300001200301490000700313520211500320653001902435653002602454653003002480653002202510653002802532653003002560653001602590100001702606700002602623700001702649700002702666856011502693 2016 eng d a0892-702200aDFT based assay for tailor-made terpyridine ligand-metal complexation properties0 aDFT based assay for tailormade terpyridine ligandmetal complexat a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcMAY a618-6270 v423 a

Electron-rich terpyridine ligand and its metal complexes have a potential to grow as responsive surfaces by adapting their physicochemical properties as a function of environment. The responsiveness is brought about by judicious molecular level designing that is currently hindered due to lack of information and control on terpyridine (TPy)-metal (M) interactions at single molecule level. So far there is no organised understanding on the binding of different metals with TPy ligand and ways to modulate it. Being a large conjugated [GRAPHICS] system, TPy has a large scope to be functionalised with electron exchanging groups to alter its electronic structure and consequently its binding with metal atoms. In first report of such a kind, using density functional theory (DFT), we demonstrate that convenient modulation of TPy-M binding is possible through functionalisation of TPy for [GRAPHICS] , Ru, Fe, Mo and Au. Electron donating groups viz., CH [GRAPHICS] , OCH [GRAPHICS] , C [GRAPHICS] H [GRAPHICS] , NH [GRAPHICS] and electron withdrawing groups viz., CF [GRAPHICS] , COOH, CN and NO [GRAPHICS] are considered for functionalisation of TPy ligand. Significantly, the present work focuses on the functionalisation at 4 and 4 [GRAPHICS] positions of TPy molecule. The role of such a functionalisation in influencing the ligands structure-property correlation is missing in the literature to the best of our knowledge. The present investigation quantifies that by pertinent functionalisation of TPy, TPy-M binding energies can be modified up to [GRAPHICS] 60kcal/mol. Our results reveal that functionalisation leads to a considerable charge redistribution within the TPy-M complex with carbon atoms in pyridine rings functioning as major electron sink/source with a corresponding red/blue shift of [GRAPHICS] stretching frequency. This modifies the red-ox, optical and other chemical properties of TPy-M complexes. In brief, the present report illustrates a way to design ligands such as TPy for diverse applications through tailor-made functionalisation using electronic structure methodology.

10aBinding energy10acharge redistribution10aDensity functional theory10afunctionalisation10aMetal organic complexes10ametal-ligand interactions10aterpyridine1 aJoshi, Krati1 aKrishnamurty, Sailaja1 aSingh, Iksha1 aSelvaraj, Kaliaperumal uhttp://library.ncl.res.in/content/dft-based-assay-tailor-made-terpyridine-ligand-metal-complexation-properties02378nas a2200169 4500008004100000022001400041245009500055210006900150260011000219300001400329490000700343520167300350100001702023700002602040700001602066856012602082 2016 eng d a1463-907600aEndohedrally doped gold nanocages: efficient catalysts for O-2 activation and CO oxidation0 aEndohedrally doped gold nanocages efficient catalysts for O2 act aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR a7068-70740 v183 a

Gold nanocages are the most attractive catalytic materials as all the atoms in the cage type clusters reside on the surface, making them available for chemisorption by reacting molecules. Due to a hollow space at the center, their chemical and catalytic properties can be tuned effectively and easily by endohedral doping. While a significant experimental and theoretical understanding is currently available on the structural and electronic properties of doped gold cages, very little information is available on their reactivity and catalytic behavior. In the present work, with the help of density functional theory calculations we demonstrate that endohedral doping leads to a notable increase in the binding energy of molecular oxygen on the gold nanocages. The enhancement in the O-2 binding energy on the doped gold cages is also confirmed by a significant decrease in the Au-O and an increase in the O-O bond lengths, corroborated by a red shift (similar to 250 cm(-1)) in the O-O stretching frequency as compared to the pristine cage. Furthermore, interestingly, the doped gold cages show very low activation barriers for the environmentally important CO oxidation reaction as compared to the pristine gold cage. Importantly, the decrease in the barrier height is comparatively greater for the rate limiting step of O-O-C-O intermediate formation and as a result the CO oxidation is expected to be more facile on the doped gold cages. Thus, the current study highlights the role of heteroatom doping in imparting new chemical and catalytic properties to gold cages and is expected to spur further research in the design of efficient gold nanocatalysts.

1 aManzoor, Dar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/endohedrally-doped-gold-nanocages-efficient-catalysts-o-2-activation-and-co-oxidation-001359nas a2200157 4500008004100000245008600041210006900127260000800196300001600204490000700220520080100227100001801028700001601046700002601062856011301088 2016 eng d00aN-2 activation on Al metal clusters: catalyzing role of BN-doped graphene support0 aN2 activation on Al metal clusters catalyzing role of BNdoped gr cOCT a27721-277270 v183 aThe successful sustenance of life demands an ambient abiotic process for N-2 activation and dissociation. The Bosch-Haber process remains the only abiotic and synthetic means for N-2 activation and its fixation. Metal nanoclusters have been recently reported for activating molecular nitrogen. Interestingly, the metal clusters explored so far for N-2 activation are free clusters and, hence, are practically not applicable by experimental chemists. Using density functional theory (DFT) based methodology, we propose a potential catalytic system for di-nitrogen activation, viz. supported Al clusters. Al clusters supported on BN doped graphene sheets are seen to activate N-2 molecule with a red shift in the N-N stretching frequency up to 874 cm(-1) with activation barriers as low as 1.14 eV.1 aKumar, Deepak1 aPal, Sourav1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/n-2-activation-al-metal-clusters-catalyzing-role-bn-doped-graphene-support01245nas a2200157 4500008004100000245009900041210006900140260000800209300001600217490000800233520065900241100001800900700002600918700001600944856012700960 2017 eng d00aDissociative adsorption of molecular hydrogen on BN-doped graphene-supported aluminum clusters0 aDissociative adsorption of molecular hydrogen on BNdoped graphen cNOV a26493-264980 v1213 aThe present work demonstrates dissociative adsorption of molecular hydrogen on supported and unsupported aluminum Wclusters (Al-n, n = 4-8, 13) using density functional theory based calculations. The studies reveal that the presence of a BN-doped graphene surface support reduces the dissociative adsorption barrier of the bond in molecular hydrogen on even atom clusters. In particular, supported Al-6 demonstrates a barrier-less dissociative adsorption toward the H-2 molecule. These results demonstrate the excellent potential of supported Al nanoparticles for hydrogen storage and also the potential of doped graphene systems are catalyzing supports.1 aKumar, Deepak1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/dissociative-adsorption-molecular-hydrogen-bn-doped-graphene-supported-aluminum-clusters01894nas a2200157 4500008004100000022001400041245004600055210004300101260000800144300001400152490000700166520144700173100001701620700002601637856007301663 2018 eng d a1463-907600aAu26: a case of fluxionality/co-existence0 aAu26 a case of fluxionalitycoexistence cAPR a8616-86230 v203 a

The Au26 cluster is one of the widely studied gold clusters in the size range of n = 21–30. It has been proposed in a more recent combined experimental and theoretical study that the neutral Au26 cluster is fluxional. The fluxionality of a cluster is relevant to its catalytic applications. In this context, to explore the extent of fluxionality, Born Oppenheimer Molecular Dynamical (BOMD) simulations are carried out on experimentally and theoretically proposed fluxional Au26 conformations (three compact or core–shell structures and a high symmetry cage structure). The simulations reveal that the high energy golden tube outperforms the ground state structure (compact C2v conformation) as well as the other two low-symmetry compact conformations in terms of thermal stability. The enhancement in the thermal stability is explained on the basis of structural integrity imposed by the open skeleton of shortest bond distances within Au26-Tube. In addition to this, the homogeneous distribution of charges and the strong s–d hybridization exhibited by FMOs are seen to play a pivotal role in increasing the stability of Au26-Tube. The present investigation also reveals that the characteristic fluxionality proposed to exist in the Au26 system is noted only above 400 K and it is missing at room temperature. The simulations also bring forth the question of how relevant a ground state conformation is at working temperatures.

1 aJoshi, Krati1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/au26-case-fluxionalityco-existence01430nas a2200193 4500008004100000022001500041245012700056210006900183260000800252300001600260490000700276520071800283100001801001700002501019700002601044700002701070700001601097856012301113 2018 eng d a 1463-907600aDissociative chemisorption of hydrogen molecules on defective graphene-supported aluminium clusters: a computational study0 aDissociative chemisorption of hydrogen molecules on defective gr cNOV a26506-265120 v203 a

Using periodic density functional theory-based calculations, in the present study, we address the chemical bonding between aluminium clusters (Al-n, n = 4-8 and 13) and monovacant defective graphene. The adsorption strength of the above-mentioned aluminium clusters is fivefold (approximate to 3 to 5 eV) higher on defective graphene as compared to the earlier reported values on non-defective graphene and BN-doped graphene. The Bader charge analysis and different charge densities reveal that this adsorption is driven by significant charge transfer from the Al clusters to defective graphene. Thus, chemisorbed Al clusters demonstrate high activity towards dissociative adsorption of molecular hydrogen.

1 aKumar, Deepak1 aGovindaraja, Thillai1 aKrishnamurty, Sailaja1 aKaliaperumal, Selvaraj1 aPal, Sourav uhttp://library.ncl.res.in/content/dissociative-chemisorption-hydrogen-molecules-defective-graphene-supported-aluminium02780nas a2200181 4500008004100000022001400041245011100055210006900166260000800235300001600243490000800259520210000267100002202367700002502389700002702414700002602441856013102467 2019 eng d a1932-744700aDinitrogen activation on graphene anchored single atom catalysts: local site activity or surface phenomena0 aDinitrogen activation on graphene anchored single atom catalysts cNOV a27492-275000 v1233 a

Catalysis on two-dimensional (2D) substrates with metal clusters or centers is generally dealt with as a surface phenomenon under the conjecture that the delocalized electron density is the driving force. When single atom catalysts (SACs) are anchored on such materials with delocalized electron density, for instance graphene, the stimulant for catalysis may be either the d-electrons on the metal or the system altogether. To understand the contributing factors of catalysis on such systems, a case study of dinitrogen (N-2) activation on Mo anchored graphene has been made by employing periodic and finite models of graphene. The periodic model represents a continuum of SACs anchored periodically on graphene, while the finite models are graphene nanoflakes of varying sizes and edge orientations. In addition to the physical aspects, such as size/finiteness of graphene, the influence of varying chemical compositions of the substrate on the activity is also evaluated by doping graphene with different B and N concentrations. This study, while clearly bringing out the connotation of regulating atomic composition of graphene substrate for dinitrogen activation, also surprisingly unveils the relative insignificance of varying the size and edge effects of the substrate. These features are highlighted through an analysis of red shift in the N-N stretching frequency, charge transfer to dinitrogen from the catalytic system, and structural and electronic characteristics of the catalytic system. The total and projected density of states plots reveal hybridization between the metal d orbitals and the p orbitals of carbon and nitrogen in the valence band. On the other hand, the frontier molecular orbital analysis also depicts a strong chemisorption of dinitrogen with the metal-graphene supports on account of direct hybridization between the d orbitals of the supported metal atom and the p orbitals of dinitrogen. The Bader and Lowdin charge distribution on the adsorbed dinitrogen in periodic and finite models shows the preeminence of local site over the surface activity.

1 aMaibam, Ashakiran1 aGovindaraja, Thillai1 aSelvaraj, Kaliaperumal1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/dinitrogen-activation-graphene-anchored-single-atom-catalysts-local-site-activity-or-surface02972nas a2200193 4500008004100000022001400041245008100055210006900136260000900205300001600214490000600230520229300236100002502529700002502554700003402579700002602613700002802639856011102667 2019 eng d a2050-748800aEffective polysulfide trapping polar interlayer for high rate Li-S batteries0 aEffective polysulfide trapping polar interlayer for high rate Li cAPR  a10067-100760 v73 a

A microporous and polymeric C3N4 framework (CNF), when exploited as an interlayer and as a cathode host in Li-S batteries, demonstrates significantly improved electrochemical behavior with a special relevance to high rate applications up to 5C. A CNF obtained through a template free synthesis approach and activated with KOH is endowed with a high specific surface area of 1000 m(2) g(-1), a desirable nitrogen content (13%) to ensure polarity and a microporous architecture, required to increase the accommodation capability of discharge products. The difference in electronegativity between C and N in CNFs combats in a major way the shuttling of lithium polysulfides (LIPSs) and ensures the realization of increased LIPS binding sites due to the presence of pyridinic nitrogen. Furthermore, a CNF driven change in the molecular configuration of adsorbed LIPSs leads to the uniform distribution and sequestration of discharge products. Similarly, micropores and the polymeric nature of CNFs facilitate the effective confinement of LIPSs and ably accommodate the volume changes (through the formation of Li2S upon discharge) respectively, especially when a microporous CNF interlayer is involved in the Li-S assembly. In particular, a CNF with 60 wt% sulfur loading, otherwise represented as CNFS-60, when exploited as a cathode in combination with the deployment of a CNF interlayer exhibits appreciable capacity values of 500 and 400 mA h g(-1) at 3 and 5C respectively. Furthermore, the combination of the CNF interlayer and cathode demonstrates a steady state discharge capacity of 437 mA h g(-1) at 1C rate up to 300 cycles, without any significant capacity loss. The involvement of chemical interaction of the CNF with lithium polysulfides is demonstrated using density functional theory calculations. Hence, the effective trapping and the subsequent localization of migrating LIPSs arising from the strong chemical interaction of the CNF with soluble LIPSs and the advantages of high concentration of accessible pyridinic nitrogen sites to the LIPS adsorption in improving the electrochemical behavior of the Li-S system could be understood. This new CNF based interlayer provides a promising approach and ample scope for its implementation in futuristic Li-S batteries.

1 aKaruppiah, Saravanan1 aKalimuthu, Balakumar1 aNazrulla, Mohammed, Azeezulla1 aKrishnamurty, Sailaja1 aNallathamby, Kalaiselvi uhttp://library.ncl.res.in/content/effective-polysulfide-trapping-polar-interlayer-high-rate-li-s-batteries02517nas a2200145 4500008004100000245013200041210006900173260000900242300001600251490000600267520191800273100002402191700002602215856013002241 2019 eng d00aMolecular and dissociative adsorption of oxygen on au-pd bimetallic clusters: role of composition and spin state of the cluster0 aMolecular and dissociative adsorption of oxygen on aupd bimetall cJULY a12687-126950 v43 a

Utilization of molecular oxygen as an oxidizing agent in industrially important reactions is the ultimate goal to design environmentally benign processes under ambient conditions. However, the high thermal stability and a large O-O dissociation barrier in O-2 molecule pose a great challenge toward its successful application in the oxidative chemistry. To achieve this goal, different catalysts based on monometallic and bimetallic clusters have been developed over the years to promote binding and dissociation of molecular oxygen. The successful design of efficient metal cluster catalysis needs an in-depth knowledge of synergistic effects between different metal atoms and intrinsic catalytic mechanisms for O-2 adsorption and dissociation. Here, we present a systematic theoretical investigation of reaction pathways for O-2 adsorption and dissociation on Au-8, Pd-8, and Au8-nPdn (n = 1-7) nanoclusters in different spin states. The density functional calculations point out that the O-2 dissociation barriers can be significantly reduced with the help of certain bimetallic clusters along specific spin channels. Our results particularly indicate that Au5Pd3 and Au1Pd7 show very large O-2 binding energies of 1.76 and 1.69 eV, respectively. The enhanced O-2 binding subsequently leads to low activation barriers of 0.98 and 1.19 eV along the doublet and quartet spin channels, respectively, without the involvement of any spin flip-over for O-2 dissociation. Furthermore, the computed O-2 dissociation barriers are significantly low as compared to the already reported barriers (1.95-3.65 eV) on monometallic and bimetallic Au-Ag clusters. The results provide key mechanistic insights into the interaction and dissociation of molecular oxygen with Au-Pd clusters, which can prove informative for the design of efficient catalysts for oxidative chemistry involving molecular oxygen as a reactant.

1 aDar, Manzoor, Ahmad1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/molecular-and-dissociative-adsorption-oxygen-au-pd-bimetallic-clusters-role-composition-and02276nas a2200253 4500008004100000022001400041245010300055210006900158260000900227300001100236490000900247520140000256653002301656653001601679653001901695653001601714653004201730653002101772100002901793700001701822700002701839700002601866856013001892 2019 eng d a2210-271X00aProbing the catalytic activity of pristine and doped Pd and Ni metal clusters towards H2O molecule0 aProbing the catalytic activity of pristine and doped Pd and Ni m cDEC  a1126240 v11703 a

Electrolysis of H2O to produce molecular hydrogen, the most environment friendly and energy efficient fuel, using cost effective catalysts is one of the major global research challenges. To date, Pt remains the best suitable and yet highly expensive electro-catalyst for hydrogen evolution reaction. Design of an alternative cost-effective catalyst requires a fundamental molecular level understanding of the water molecule adsorption and its activation. In that context, we examine the adsorption and activation of water molecule on model alternative catalysts namely, Ni-6 and Pd-6 clusters using density functional theory based methodology. Ni-6 and Pd-6 clusters and their singly doped counterparts are used for this study. Mo, W, Fe, Co and Cu are used as doping elements. To quantify the influence of medium (neutral and alkaline) on the activation of the water molecule, Ni based clusters are considered in neutral and anionic states, respectively. The activity of these clusters towards H2O molecule is evaluated in terms of the adsorption energy, charge transfer, bandgap, red shift in O-H stretching frequency and dissociation barriers for H2O. The studies demonstrate that doping with Co in all the studied clusters (Pd-6, Ni-6 and anionic Ni-6) increases their activity. Best activity is noted for Fe doped neutral Ni b clusters with a dissociation barrier of 5.76 kcal/mol.

10aActivation barrier10aNi clusters10aO-H activation10aPd clusters10aRed shift of O-H stretching frequency10aWater adsorption1 aSamal, Pragnya, Paramita1 aJoshi, Krati1 aKaliaperumal, Selvaraj1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/probing-catalytic-activity-pristine-and-doped-pd-and-ni-metal-clusters-towards-h2o-molecule02122nas a2200265 4500008004100000022001400041245013800055210006900193260000900262300001400271490000700285520121800292653002001510653001501530653001901545653002501564653001401589653000901603100002201612700002901634700001801663700002601681700002001707856012901727 2020 eng d a2155-543500aIron-catalyzed C(sp(2))-H alkylation of indolines and benzo[h]quinoline with unactivated alkyl chlorides through chelation assistance0 aIroncatalyzed Csp2H alkylation of indolines and benzohquinoline  cJUL  a7312-73210 v103 a

Regioselective C-H bond alkylation of indolines and benzo[h]quinoline with a wide range of unactivated and highly demanded primary and secondary alkyl chlorides is accomplished using a low-cost iron catalyst. This reaction tolerates diverse functionalities, such as C(sp(2))-Cl, fluoro, alkenyl, silyl, ether, thioether, pyrrolyl, and carbazolyl groups including cyclic and acyclic alkyls as well as alkyl-bearing fatty-alcohol and polycyclic-steroid moieties. The demonstrated iron-catalyzed protocol proceeded via either a five-membered or a six-membered metallacycle. Intriguingly, the C-7-alkylated indolines can be readily functionalized into free-NH indolines/indoles and tryptamine derivatives. A detailed mechanistic investigation highlights the participation of an active Fe(I) catalyst and the involvement of a halogen-atom transfer process via a single-electron-based mechanism. Deuterium labeling and kinetics analysis indicate that the C-H metalation of indoline is the probable turnover-limiting step. Overall, the experimental and theoretical studies supported an Fe(I)/Fe(III) pathway for the alkylation reaction comprising the two-step, one-electron oxidative addition of alkyl chloride.

10aalkyl chlorides10aAlkylation10aC-H activation10achelation assistance10aindolines10airon1 aJagtap, Rahul, A.1 aSamal, Pragnya, Paramita1 aVinod, C., P.1 aKrishnamurty, Sailaja1 aPunji, Benudhar uhttp://library.ncl.res.in/content/iron-catalyzed-csp2-h-alkylation-indolines-and-benzohquinoline-unactivated-alkyl-chlorides01231nas a2200169 4500008004100000022001400041245012300055210006900178260000900247300001600256490000700272520058700279100001700866700002600883700002400909856012800933 2020 eng d a1463-907600aSurface functionalization: an efficient alternative for promoting the catalytic activity of closed shell gold clusters0 aSurface functionalization an efficient alternative for promoting cOCT  a23351-233590 v223 a

{Surface functionalization through adsorption of ligands or non-metal atoms is considered to be an interesting and viable approach for tuning the physicochemical properties of gold clusters. Highly stable and magic numbered electronic configurations of thiolate protected gold clusters such as Au-25(SR)(18), Au-38(SR)(24)etc. with intriguing properties are the direct manifestation of the rich chemistry of the Au-S interface. The present investigation discerns the CO oxidation activity of structurally well characterized sulphur functionalized gold cluster anions AumS4-

1 aJoshi, Krati1 aKrishnamurty, Sailaja1 aDar, Manzoor, Ahmad uhttp://library.ncl.res.in/content/surface-functionalization-efficient-alternative-promoting-catalytic-activity-closed-shell02700nas a2200265 4500008004100000022001400041245016000055210006900215260000800284300001100292490000800303520172400311653003002035653003202065653001702097653001902114653003702133100002202170700001902192700001702211700002502228700002602253700002702279856012802306 2020 eng d a0304-389400aUnravelling the distinct surface interactions of modified graphene nanostructures with methylene blue dye through experimental and computational approaches0 aUnravelling the distinct surface interactions of modified graphe cAPR a1217550 v3883 a

Nanoscopic modifications leading to multi-dimensional graphene structures are known to significantly influence their candidature for several applications including catalysis, energy storage, molecular sensing and most significantly adsorption and remediation of harmful materials such as dyes. The present work attempts to identify the key trajectories that connect the structural qualification with a chosen application, viz., the interactive forces in dye remediation. Various physico-chemically Modified Graphene Nanostructures (MGNs) such as 2 dimensional Graphite, Graphene Oxide (GO), reduced GO (rGO), holey rGO, and 3 dimensional GO hydrogel and Holey GO hydrogel are chosen and synthesised herein. These represent varieties of physicochemical features with respect to their dimensionality, surface features such as oxygen functionality, nanoscopic holes etc., that contribute to their characteristic overall surface interactions. Methylene Blue (MB), a popular industrial effluent posing major environmental concern is chosen to be a probe adsorbate in this case study. An exclusive real time in-situ UV visible spectral experiment provides the revealing reasons behind the outstanding performance of 2D GO sheets with an adsorption capacity of greater than 92 % even at high MB concentrations (>2000 ppm). A complex dependency of various factors such as surface oxygen, morphology, nanoporosity etc. on the unique overall interaction with an adsorbent such as MB by all these adsorbates is demonstrated using experimental and DFT based computational studies. Electrostatics and hydrogen bonding are understood to be the two dominant forces driving the MB adsorption on the best performing GO here.

10aDensity functional theory10aIn-situ UV-vis spectroscopy10aInteractions10aMethylene blue10aModified Graphene Nanostructures1 aManappadan, Zinoy1 aKumar, Shubham1 aJoshi, Krati1 aGovindaraja, Thillai1 aKrishnamurty, Sailaja1 aSelvaraj, Kaliaperumal uhttp://library.ncl.res.in/content/unravelling-distinct-surface-interactions-modified-graphene-nanostructures-methylene-blue03404nas a2200229 4500008004100000022001400041245021300055210006900268260000800337300001600345490000800361520247400369100002702843700002202870700003402892700001802926700001902944700002602963700003002989700002703019856012803046 2020 eng d a1932-744700aUnsymmetrical squaraine dyes for dye-sensitized solar cells: position of the anchoring group controls the orientation and self-assembly of sensitizers on the TiO2 surface and modulates its flat band potential0 aUnsymmetrical squaraine dyes for dyesensitized solar cells posit cAUG a18436-184510 v1243 a

The position of the anchoring group is systematically changed with a series of alkyl group wrapped donor-acceptor-donor (D-A-D) based squaraine dyes, 4-SQ to 7-SQ, for the use in dye-sensitized solar cells (DSSCs). By this approach, the orientation as well as the self-assembly of the sensitizers can be controlled on the semiconducting TiO2 surface. All of the dyes functionalized with hydrophobic alkyl groups at sp(3)-C and N atoms of the indoline units that is far away from the TiO2 surface to control the self-assembly of dyes and passivate the surface. Controlling both the orientation as well as the self-assembly of the sensitizers synergistically enhances the V-oc of the DSSC device by imparting the dipole moment on the TiO2 surface and minimizing the interfacial charge recombination process of electrons from TiO2 to the oxidized electrolyte, respectively. Further, the presence of a meta-carboxyl group with respect to the N atom of the indoline donor unit for the dyes 4-SQ and 6-SQ makes them nonconductive for the charge injection process, which sheds light on the importance of through-space electron transfer for the device performance. Emission from the relaxed twisted state was found to be a deactivation pathway for 4-SQ on TiO2 and ZrO2, which revealed the importance of structural factors that promote spatial interaction between the sensitizer and metal oxide surface. Computational studies showed the systematic changes in the dipole moment for the sensitizers 4-SQ, 5-SQ, and 6-SQ upon anchoring to the TiO2 surface. The DSSC device performance varied with the position of anchoring groups in the sensitizers. The DSSC device performance of 5-SQ indicates a J(sc) value of 11.35 mA cm(-2), V-oc of 0.698 V, and ff of 77% corresponding to a power conversion efficiency of 6.08% in the presence of 3 equiv of coadsorbent CDCA, which is nearly 1.5 times higher than 6-SQ (V-oc 0.7 V, J(sc) 7.76 mA cm(-2), ff 76%, and eta 4.14%) and 2.6 times higher than 4-SQ (V-oc 0.658 V, J(sc) 4.42 mA cm(-2), ff 78%, and eta 2.28%). IPCE studies revealed the importance of orientation for the charge injection and self-assembly of dyes, as devices with 5-SQ and 6-SQ as a sensitizer showed 94 and 77% response at 578 nm, respectively, which correspond to the aggregated structure of the dye. Mott-Schottky and IPCE experiments showed that the orientation of sensitizers could modulate the V-oc due to the shift in the flat band potential of TiO2.

1 aSingh, Ambarish, Kumar1 aMaibam, Ashakiran1 aJavaregowda, Bharathkumar, H.1 aBisht, Rajesh1 aKudlu, Ashwath1 aKrishnamurty, Sailaja1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttp://library.ncl.res.in/content/unsymmetrical-squaraine-dyes-dye-sensitized-solar-cells-position-anchoring-group-controls01963nas a2200253 4500008004100000022001400041245011500055210006900170260000800239300001400247490000700261520109300268653001501361653001801376653001401394653001801408653002001426100003801446700001801484700002201502700002601524700003001550856012901580 2021 eng d a1867-388000aDurable metalloporphyrin 2D-polymer for photocatalytic hydrogen and oxygen evolution from river and sea waters0 aDurable metalloporphyrin 2Dpolymer for photocatalytic hydrogen a cAPR a1717-17210 v133 a

It is highly imaginary that the outcome of a combination of two complementary resources leads to answer an alarming global issue. One such possible example is the solar seawater splitting for `clean fuel' H-2 generation. Since the catalytic activity and stability of the photocatalysts are substantially challenged in seawater, the design of an efficient and stable photocatalyst is highly desirable. Herein, we demonstrate the solar seawater splitting by a two-dimensional polymer catalyst derived from metalloporphyrin bearing multi-hydroxyl groups. A bimetallic (Co and Ni) porphyrin 2D-polymer exhibits excellent long-term durability of 15 cycles of H-2 and O-2 generation in 200 days from pure water without a considerable decrease in efficiency. Detailed studies using river and seawaters also show the reliable performance of the catalyst over repeated cycles. Here the deactivation modes of catalytic activity have been nullified by the layered metalloporphyrin polymer structure through stable pi-pi stacking, signifying the molecular design of 2D-polymer photocatalyst.

10a2D-polymer10aPhotocatalyst10aporphyrin10aSelf-assembly10awater splitting1 aRanjeesh, Kayaramkodath, Chandran1 aGeorge, Leena1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja1 aBabu, Sukumaran, Santhosh uhttp://library.ncl.res.in/content/durable-metalloporphyrin-2d-polymer-photocatalytic-hydrogen-and-oxygen-evolution-river-and01429nas a2200133 4500008004100000245009700041210006900138260000800207520088800215100002201103700002601125700002401151856012001175 2021 eng d00aElectrocatalytic nitrogen reduction directed through the p-band center of boron on BSAC@Mo2C0 aElectrocatalytic nitrogen reduction directed through the pband c cNOV3 aGreener modes of ammonia synthesis via the electrocatalytic route have been investigated on pristine and defective Mo2C based monolayers anchored with metal-free boron atom catalysts. Boron single atom catalysts (SACs) on the defective Mo2C monolayer has been found to activate N2 strongly with an adsorption energy of −1.92 eV and reduce it to NH3 efficiently with a significantly low overpotential of 0.41 eV. The exothermic adsorption of N2 and low overpotential for the nitrogen reduction reduction (NRR) appertain to the p-band center of the boron atom catalyst and charge transfer between the adsorbed N2 and the catalyst, respectively. This work brings forth the correlation between electron occupancy on the boron center and NRR catalytic efficiency on a metal-free SACs@Mo2C monolayer couple, thereby serving as a lead in designing metal free electrocatalysts for the NRR.1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja1 aDar, Manzoor, Ahmad uhttp://library.ncl.res.in/content/electrocatalytic-nitrogen-reduction-directed-through-p-band-center-boron-bsacmo2c02036nas a2200169 4500008004100000245008100041210006900122260000900191300001600200490000700216520143400223100002201657700002201679700002901701700002601730856011001756 2021 eng d00aEnhanced photocatalytic properties of a chemically modified blue phosphorene0 aEnhanced photocatalytic properties of a chemically modified blue cAPR  a13348-133580 v113 a

It is high time to placate the peak demand for an efficient, economic and green fuel in the form of H-2 through photocatalytic water splitting. Several low dimensional materials have been explored for their photocatalytic properties on account of their surface to volume ratio. The present study illustrates the excellent photocatalytic potential of a two-dimensional material, viz. a chemically tempered blue-phosphorene sheet, with single atom thickness and high carrier mobility. Metal-free element, sulphur, is explored as a dopant in a 32-atom blue-phosphorene sheet. The dopant is inserted at three locations viz. central, edge and central edge positions with varying concentrations from 3.125% to 18.75% (corresponding to n = 1 to 6 sulphur atoms within a 32-atom blue-phosphorene sheet, P32-nSn). The cohesive energy studies predict the higher stability of even number S doped sheets as compared to their odd counterparts. Photocatalytic activity is studied in terms of band gap and band alignment for different concentrations of the former. Studies reveal that edge doping demonstrates better water molecule activation independent of S atom concentration. The edge doped systems not only provide the chemical activity to activate water, but also show feasible HER overpotentials of 1.24-1.29 eV at neutral medium. Finally, this work opens up a driving lead of non-corrosive catalysts for water molecule splitting.

1 aMaibam, Ashakiran1 aDas, Sawan, Kumar1 aSamal, Pragnya, Paramita1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/enhanced-photocatalytic-properties-chemically-modified-blue-phosphorene02150nas a2200181 4500008004100000022001400041245010700055210006900162260000800231300001400239490000700253520149300260100002201753700002601775700001701801700002601818856012401844 2021 eng d a1144-054600aExploring edge functionalised blue phosphorene nanoribbons as novel photocatalysts for water splitting0 aExploring edge functionalised blue phosphorene nanoribbons as no cFEB a3570-35800 v453 a

Hydrogen gas, a highly combustible and eco-friendly fuel is stealing the limelight and its production is one of the major areas of research. An efficient and green method for producing clean hydrogen gas with no harmful by-product is water splitting. With the introduction of low dimensional materials, water splitting has become an easier and cost-effective process. The present work demonstrates the application of one such low dimensional material viz., edge functionalised Blue Phosphorene Nano-Ribbons (BPNRs) as potential photocatalysts. With a carrier mobility of 10(3) cm(2) V-1 s(-1) and a band gap of 1.5-3.0 eV, BPNRs are an attractive candidate for photocatalysis. BPNRs with different edge oreintations, viz. zigzag and armchair are functionalised with CH3O, COOCH3, CHO, COOH, OH, NH2, CONH2, SH, C6H5, and NO2 groups. Their performance towards activating water molecules at different sites on the nanoribbon is studied. The functionalised edges of the BPNRs are the active sites showing similar to 1.2% to 3.2% efficiency in activating the O-H bond of the water molecule. Among the different groups explored, CONH2 functionalised zigzag BPNR clearly exhibits a higher potential towards the adsorption of water molecules (-0.98 eV) and activation of O-H bonds with an elongation of 3.2% and a red shift of 500.6 cm(-1). This is attributed to the lone pair of electrons on the nitrogen atom contributing to the electron donating nature of the CONH2 functional group.

1 aMaibam, Ashakiran1 aChakraborty, Debalina1 aJoshi, Krati1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/exploring-edge-functionalised-blue-phosphorene-nanoribbons-novel-photocatalysts-water02724nas a2200169 4500008004100000022001400041245017900055210006900234260000800303300001400311490000700325520202600332100001702358700002202375700002602397856013102423 2021 eng d a1144-054600aFinite temperature behavior of carbon atom-doped silicon clusters: depressed thermal stabilities, coexisting isomers, reversible dynamical pathways and fragmentation channels0 aFinite temperature behavior of carbon atomdoped silicon clusters cMAY a8217-82270 v453 a

Silicon carbide clusters are significant due to their predominant occurrence in meteoric star dust, particularly in carbon-rich asymptotic giant branch stars. Of late, they have also been recognized as nanoclusters with potential applications in technology. Them both being elements of the same group, there is excellent potential for precise control over the physico-chemical properties of such molecular length-scale materials through atomic engineering and this has been explored recently by various experimentalists. This report simulates one of the significant physical properties, viz. conformational stability, of various carbon-doped silicon clusters as a function of temperature using Born-Oppenheimer molecular dynamics methodology. Single carbon atom-doped silicon clusters with 4-9 atoms (i.e., Si3C-Si8C) are chosen for this study as the gas phase geometries of these clusters have been characterized using a combination of experimental and theoretical methods in the recent past. The simulations ratify that various conformations do not interconvert among themselves at 300 K. The interconversion occurs at 500 K or above, thereby ratifying the possibility of the coexistence of multiple conformations of a given cluster, which are generally synthesized under subroom temperature conditions. Furthermore, the above single carbon atom-doped silicon clusters: (a) have depressed thermal stabilities as compared to their pristine counterparts with the exception of a Si5C conformation; (b) undergo multifarious evolution of the cluster, through the reversible dynamical and fragmentation pathways as a function of temperature and (c) single carbon atom-doped silicon clusters with 7 atoms (starting from Si6C) and above undergo a fragmentation at nearly 2000 K. The underlying electronic and structural properties of various clusters are discussed to explain the above observations with a note on critical fragmentation energy barriers required for the segmentation of clusters with seven or more atoms.

1 aJoshi, Krati1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/finite-temperature-behavior-carbon-atom-doped-silicon-clusters-depressed-thermal-stabilities02264nas a2200169 4500008004100000022001400041245018100055210006900236260000900305300001400314490000700328520153700335100004301872700002601915700002701941856012601968 2021 eng d a1144-054600aGraphene-based frustrated Lewis pairs as bifunctional catalysts for CO2 reduction via the dissociative chemisorption of molecular H-2: a periodic density functional perspective0 aGraphenebased frustrated Lewis pairs as bifunctional catalysts f cJUN  a9959-99660 v453 a

Nanocarbon-based frustrated Lewis pair (FLP) bifunctional catalysts, on account of their unquenched electron transfer property, are becoming increasingly attractive as catalysts for the CO2 reduction reaction via the dissociative chemisorption of H-2. In the present study, we propose a nanocarbon-based FLP catalyst. The pair comprises nitrogen doped/phosphorus doped graphene as Lewis bases and M(C6F5)(3) (M = B, Al, Ga, and In) as Lewis acids. The computational investigation reveals that the carbon atoms adjacent to the doped N and P atoms are the active sites towards the dissociative chemisorption of hydrogen molecule. The analyses of the Bader charges and difference charge densities validate the dissociative chemisorption of H-2 molecule and the fact that a significant electron redistribution promotes the polarization of the hydrogen molecule. Density of states confirms the hybridization between the p-states of the nitrogen/phosphorus atom and the s-state of hydrogen atom in all FLPs. The dissociative chemisorption of hydrogen is noted in all FLP complexes, thereby facilitating a low barrier reaction path for CO2 reduction. Between P-doped and N-doped FLPs, N-doped FLP catalysts prove to be a more promising counterpart with considerably low activation barriers, ranging between 0.01 and 0.11 eV, towards CO2 reduction. Thus, the present study demonstrates the great potential of doped carbon-based FLPs as novel nanostructure catalysts for CO2 reduction via the direct utilization of molecular hydrogen.

1 aSenthamaraikannan, Thillai, Govindaraj1 aKrishnamurty, Sailaja1 aKaliaperumal, Selvaraj uhttp://library.ncl.res.in/content/graphene-based-frustrated-lewis-pairs-bifunctional-catalysts-co2-reduction-dissociative01901nas a2200193 4500008004100000022001400041245018300055210006900238260000800307300001400315490000700329520113700336100001901473700002901492700002601521700001501547700002001562856012501582 2021 eng d a1463-926200aAn innovative light assisted production of acetic acid from CO2 and methanol: a first photocatalytic approach using a reusable cobalt(ii) molecular hybrid at atmospheric pressure0 ainnovative light assisted production of acetic acid from CO2 and cNOV a9048-90600 v233 aAcetic acid is an important commodity chemical that is produced either by fermentation processes, or more commonly, through chemical routes such as methanol carbonylation with CO and H-2, acetaldehyde oxidation, or hydrocarbon oxidation. More recently, methanol hydrocarboxylation with CO2 and H-2 under thermal catalytic conditions has attracted interest. The synthesis of acetic acid from easily available CO2 is of great significance yet rarely reported. The present paper describes the first photocatalytic approach for the synthesis of acetic acid from methanol and CO2 under ambient reaction conditions without using molecular hydrogen. The maximum conversion of methanol achieved is 60% with a selectivity of 81% towards acetic acid using an octa-sulfur bound cobalt phthalocyanine (CoPc/S8) photocatalyst without an additional sacrificial electron donor. Product analysis, controlled experiments and DFT calculations suggest the formation of methylene carbene as a reactive intermediate. The developed methodology represents a potentially exciting approach for synthesizing acetic acid utilizing CO2 in a sustainable manner.1 aSaini, Sandhya1 aSamal, Pragnya, Paramita1 aKrishnamurty, Sailaja1 aRay, Anjan1 aJain, Suman, L. uhttp://library.ncl.res.in/content/innovative-light-assisted-production-acetic-acid-co2-and-methanol-first-photocatalytic02877nas a2200277 4500008004100000022001400041245014900055210006900204260000800273300001600281490000600297520188700303653003702190653001702227653000802244653002302252653001302275653002002288653003002308100002502338700002202363700002902385700002602414700002902440856013002469 2021 eng d a2168-048500aMechanistic investigations on the catalytic transfer hydrogenation of lignin-derived monomers over Ru catalysts: theoretical and kinetic studies0 aMechanistic investigations on the catalytic transfer hydrogenati cOCT a14040-140500 v93 aThe hydrodeoxygenation (HDO) reaction of oxygenated compounds such as lignin-derived phenolics is well studied using molecular H-2 as a hydrogen source, yet the use of high pressures discourages its use on an industrial scale. As an alternative, the catalytic transfer hydrogenation (CTH) pathway provides in situ hydrogenation species, which reduces the need for the high-pressure infrastructure required when molecular hydrogen is used. Nevertheless, this strategy is scantly studied, and in lieu with this, herein we report the kinetic and mechanistic investigations of the CTH strategy for the HDO of guaiacol, phenol, anisole veratrole, and eugenol to their respective products. For potential commercialization purposes, low loading of metal, milder reaction conditions, and high selectivity toward desired products with a high H/C ratio were considered while designing catalysts (0.5 wt % Ru on SiO2-Al2O3, SiO2, Al2O3-acidic, Al2O3-basic, and Al2O3-neutral) for these reactions. As high as 74% cyclohexanol yield from guaiacol was achieved at 225 degrees C in the presence of isopropyl alcohol (IPA) as the hydrogen source and over the Ru/Al2O3-acidic catalyst reduced at 150 degrees C. A detailed kinetic study is carried out to understand the interaction of the substrate and intermediates with the catalyst and the influence of reaction parameters on the product formation. It was observed that the cisisomer of 2-methoxycyclohexanol rapidly undergoes further conversion than the trans-isomer. The experimental observations are substantiated through density functional theory (DFT) studies on Ru(0001) and guaiacol molecule complexes. DFT studies indicate that the adsorption of the cis-isomer is more exothermic as compared to that of the trans counterpart, and the underlying electronic factors are elucidated using charge density difference and density of states plots.10acatalytic transfer hydrogenation10aCyclohexanol10aDFT10aHydrodeoxygenation10akinetics10alignin monomers10aSupported metal catalysts1 aKhan, Tufeil, Sartaj1 aSingh, Dheerendra1 aSamal, Pragnya, Paramita1 aKrishnamurty, Sailaja1 aDhepe, Paresh, Laxmikant uhttp://library.ncl.res.in/content/mechanistic-investigations-catalytic-transfer-hydrogenation-lignin-derived-monomers-over-ru01870nas a2200289 4500008004100000022001400041245013600055210006900191260000900260300001600269490000700285520090000292653001901192653001901211653002001230653001201250653001401262653001101276653002301287100002801310700002901338700001801367700002401385700002601409700002001435856012501455 2021 eng d a2155-543500aNi(II)-catalyzed intramolecular C-H/C-H oxidative coupling: an efficient route to functionalized cycloindolones and indenoindolones0 aNiIIcatalyzed intramolecular CHCH oxidative coupling an efficien cOCT  a12384-123930 v113 aNickel(II)-catalyzed intramolecular C(sp(2))-H/C(sp(3))-H and C(sp(2))-H/C(sp(2))-H oxidative couplings in indoles are achieved via chelation assistance. These reactions provide access to biologically relevant five- and six-membered substituted cyclopentaindolones, carbazolones, and indenoindolones in high yields and good chemoselectivity employing an air-stable and defined nickel catalyst, (bpy)Ni(OAc)(2). The oxidative cyclizations proceeded either through a six-membered or an unconventional seven-membered nickelacycle. An extensive mechanistic investigation by experiments and theoretical calculations revealed a facile indole's C(2)-H nickelation and a rate-limiting reductive elimination process. This intramolecular oxidative cyclization operates via a probable Ni(II)/Ni(III) pathway involving single-electron oxidation of nickel without the participation of a carbon-based radical.10aC-H activation10acycloindolones10aindenoindolones10aindoles10aMechanism10aNickel10aoxidative coupling1 aAnkade, Shidheshwar, B.1 aSamal, Pragnya, Paramita1 aSoni, Vineeta1 aGonnade, Rajesh, G.1 aKrishnamurty, Sailaja1 aPunji, Benudhar uhttp://library.ncl.res.in/content/niii-catalyzed-intramolecular-c-hc-h-oxidative-coupling-efficient-route-functionalized02741nas a2200145 4500008004100000245013400041210006900175260000800244300001200252490000800264520214400272100002202416700002602438856013102464 2021 eng d00aNitrogen activation to reduction on a recyclable V-SAC/BN-graphene heterocatalyst sifted through dual and multiphilic descriptors0 aNitrogen activation to reduction on a recyclable VSACBNgraphene  cMAY a480-4910 v6003 a

Efficient reduction of nitrogen to ammonia at a minimal cost would require a recherche catalyst tailored by assimilating the inherent electronic and reactive nature of Single Atom Catalysts (SACs) on heteroatom doped-graphene. A full-scale DFT study accounting for disparate descriptions of atomic orbitals and representation of support, has been carried out to identify the most active and recyclable SAC/B-graphene composite as catalyst for Nitrogen Reduction Reaction (NRR). Dual and Multiphilic descriptors derived reactivity pattern of six different metal SACs V, Fe, Ni, Ru, W and Re on periodic and non-periodic paradigms of pristine and BN-pair doped graphene supports, align with the calculated chemisorption efficacy and activation of N2. The enzymatic route of nitrogen reduction on three most ideal metal SACs (V, W and Re) culminates Vanadium SAC, a relatively cheaper metal, anchored on BNring-graphene with an energy barrier of ⩽1.24 eV as a highly active and recyclable catalyst for NRR.

1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/nitrogen-activation-reduction-recyclable-v-sacbn-graphene-heterocatalyst-sifted-through-dual01933nas a2200157 4500008004100000022001400041245013800055210006900193260000800262490000600270520127200276100004301548700002701591700002601618856013101644 2021 eng d a2296-264600aRole of chemical structure of support in enhancing the catalytic activity of a single atom catalyst toward NRR: a computational study0 aRole of chemical structure of support in enhancing the catalytic cSEP0 v93 aUsing the periodic density functional theory–based methodology, we propose a potential catalytic system for dinitrogen activation, viz., single metal atoms (Mo, Fe, and V) supported on graphene-based sheets. Graphene-based sheets show an excellent potential toward the anchoring of single atoms on them (Mo, Fe, and V) with adsorption energies ranging between 1.048 and 10.893 eV. Factors such as defects and BN doping are noted to enhance the adsorption energies of single metal atoms on the support. The adsorption of a dinitrogen molecule on metal atom–anchored graphene-based supports is seen to be highly favorable, ranging between 0.620 and 2.278 eV. The adsorption is driven through a direct hybridization between the d orbitals of the metal atom (Mo, Fe, and V) on the support and the p orbital of the molecular nitrogen. Noticeably, BN-doped graphene supporting a single metal atom (Mo, Fe, and V) activates the N2 molecule with a red shift in the N–N stretching frequency (1,597 cm−1 as compared to 2,330 cm−1 in the free N2 molecule). This red shift is corroborated by an increase in the N–N bond length (1.23 Å from 1.09 Å) and charge transfer to an N2 molecule from the catalyst.1 aSenthamaraikannan, Thillai, Govindaraj1 aKaliaperumal, Selvaraj1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/role-chemical-structure-support-enhancing-catalytic-activity-single-atom-catalyst-toward-nrr01878nas a2200253 4500008004100000022001400041245011500055210006900170260000800239300001100247490000800258520105200266653001601318653001101334653002701345653000801372653001401380653001901394653001401413100002901427700001101456700002601467856013101493 2021 eng d a0169-433200aSubstrate augmented catalytic activity towards NRR: a case study of Li doped Al clusters on defective graphene0 aSubstrate augmented catalytic activity towards NRR a case study  cNOV a1505860 v5663 aDensity Functional Theory (DFT) based methods are applied to examine the potential of lithium doped aluminium clusters consisting of 3-13 atoms for dinitmgen molecule activation in terms of N N bond length, redshift in N N bond stretching frequency, nitrogen interaction energy and frontier molecular orbitals analysis. The present work highlights the role of monovacant C-3 defective graphene as a support in fine tuning the catalytic activity of Li doped Al clusters for reduction of N-2. Fundamental insights to synergic binding of clusters with defective graphene is brought out and its role in enhancing activation of dinitmgen molecule is explained. Supported Aln-1Li clusters with six or more atoms are noted to be more active towards N-2 molecule activation as compared to the clusters without support. Dinitrogen molecule undergoes a maximum bond elongation of 1.56 angstrom corresponding to redshift of 1690 cm(-1) on Al7Li@graphene and Al12Li@graphene. This is maximum value reported in context of activation for N-2 molecule till date.10aAl clusters10aAl12Li10aC-3 defective graphene10aDFT10aLi Doping10aN-2 activation10aRed-shift1 aSamal, Pragnya, Paramita1 aPoonam1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/substrate-augmented-catalytic-activity-towards-nrr-case-study-li-doped-al-clusters-defective01362nas a2200241 4500008004100000022001400041245008300055210006900138260000800207300000800215490000800223520055400231653000900785653002900794653002200823653004300845653001700888653002200905100003000927700002900957700002600986856010801012 2021 eng d a1432-881X00aThermal stability of an endohedrally doped aluminum nanoclusters: a BOMD study0 aThermal stability of an endohedrally doped aluminum nanoclusters cSEP a1320 v1403 aIn this article, thermal stability of doped Al-13 nanoclusters has been systematically investigated within the framework of density functional theory (DFT). To explain thermal stability, simulations have been carried out over a temperature range from 300 to 1100 K using Born-Oppenheimer molecular dynamics (BOMD). The atomic displacements have been quantified by calculating delta(rms,) MSD and epsilon(pro.) The thermal stability of different clusters is explained using underlined electronic properties such as HOMO-LUMO, charges and bond length.10aBOMD10aBond length fluctuations10aEndohedral doping10aMean squared ionic displacements (MSD)10aNanoclusters10aRoot mean squared1 aSingh, Chandrodai, Pratap1 aSamal, Pragnya, Paramita1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/thermal-stability-endohedrally-doped-aluminum-nanoclusters-bomd-study02872nas a2200265 4500008004100000022001400041245015900055210006900214260000800283300001100291490000800302520192200310653002202232653003002254653002102284653002302305653001802328653002002346100002002366700002002386700003002406700002602436700002102462856012302483 2022 eng d a0925-838800aFacile fabrication of nano silver phosphate on B-doped g-C3N4: an excellent p-n heterojunction photocatalyst towards water oxidation and Cr (VI) reduction0 aFacile fabrication of nano silver phosphate on Bdoped gC3N4 an e cMAR a1628530 v8983 aA photostable Ag3PO4/BCN type-II p-n heterojunction has been demonstrated by loading nano Ag3PO4 on B-doped g-C3N4 nanosheet (BCN). The photocatalysts were successfully characterized by various physicochemical techniques and their photocatalytic activities were tested towards the water oxidation reaction to produce oxygen and Cr (VI) reduction under visible light. The HRTEM confirms Ag3PO4 with a particle size of 15 nm has been deposited on BCN to construct a p-n heterojunction. The BCNS-50 absorbs more visible light in the solar spectrum as compared to other catalyst, demonstrating the ability to generate 587 mu mol h(-1)g(-1) O-2 and reduces 98% of 20 ppm Cr (VI) solution in 1 h. The lower PL intensity as well as lower arc value in case of BCNS-50 suggests the maximum e-h separation and lower charge transfer resistance across the semiconductor/electrolyte interface. The BCN sheet provides a compact heterojunction where the oxidation peak of Ag3PO4 decreases gradually and disappear in case of BCNS-50 suggesting the enhance stability of Ag3PO4 in the heterojunction. BCNS-50 could able to produce -139 and 3087.5 mu A photocurrent both in cathodic and anodic direction which is approximately 7 and 2.4 folds higher as compared to nano Ag3PO4. The generation of photocurrent in both cathodic and anodic direction confirms the formation of p-n heterojunction which further supported by Mott-Schottky analysis. Furthermore the construction of the p-n heterojunction is verified via Mott-Schottky study. DFT calculation explains the contribution of various atomic orbital of Ag3PO4 and BCN towards the formation of hybrid orbital in the heterojunction and the path for charge delocalization between them. This work may provide a limelight and alternative pathway for enhanced photocatalytic performance on construction of the p-n heterojunction in a simple way. (C) 2021 Elsevier B.V. All rights reserved.10aCr (VI) reduction10aDensity functional theory10aInterfacial zone10ap-n heterojunction10aPhotocatalyst10aWater oxidation1 aSahoo, Mitarani1 aBabu, Pradeepta1 aSingh, Chandrodai, Pratap1 aKrishnamurty, Sailaja1 aParida, Kulamani uhttp://library.ncl.res.in/content/facile-fabrication-nano-silver-phosphate-b-doped-g-c3n4-excellent-p-n-heterojunction02820nas a2200313 4500008004100000245018800041210006900229260000800298300001600306490000600322520168400328653002302012653001802035653003302053653003202086653002002118653003302138653002202171100002002193700001602213700001702229700001702246700002002263700001902283700002402302700002602326700002402352856013002376 2022 eng d00aFirst-principles investigation of the electrocatalytic reduction of CO2 on zirconium-based single-, double-, and triple-atom catalysts anchored on a graphitic carbon nitride monolayer0 aFirstprinciples investigation of the electrocatalytic reduction  cOCT a15409-154170 v53 a

Conversion of carbon dioxide (CO2) with the help of an appropriate electrocatalyst with high stability, low onset potential, and exceptional selectivity is still one of the great tasks in the electrocatalytic reduction of CO2 to valuable chemicals. Herein, by means of systematic first-principles simulations, we investigate the CO2 reduction reaction (CO2RR) activity of zirconium-based single-, double-, and triple-atom (Zrn@C2N; n = 1-3) catalysts anchored on a graphitic carbon-nitride monolayer. In tune with the Sabatier principle, our results reveal that a moderate CO2 binding is vital for a low onset potential for the CO2RR. Consequently, based on rigorous free energy calculations, the Zr-based single-atom catalyst (SAC) is found to be most effective to convert CO2 to valuable products such as HCOOH and CH3OH. It is worth noting that CO2 reduction to HCOOH is spontaneous via the *HCOO intermediate on Zr1@C2N and involves a low onset potential of -0.23 V with respect to the reversible hydrogen electrode from the *COOH intermediate. Among all the catalysts evaluated computationally, the Zr SAC further reveals the lowest onset potential of -0.89 V for CH3OH formation. The results show that the Zr-based catalysts especially Zr1@C2N are found to effectively suppress the competitive hydrogen evolution reaction and promote the CO2RR. Moreover, all three catalysts exhibit high kinetic and thermal stability with negligible distortion due to which their structures can be retained very well up to 600 K. Thus, the current work may provide effective catalyst-design strategies for enhancing the electrocatalytic CO2RR performance of Zr-based materials.

10aC1 and C2 products10aCO2 reduction10afirst-principles simulations10ahydrogen evolution reaction10aonset potential10asingle-atom catalysts (SACs)10aZrn@C2N catalysts1 aHassan, Afshana1 aAnis, Insha1 aShafi, Sadaf1 aAssad, Assif1 aRasool, Anjumun1 aKhanam, Romana1 aBhat, Gulzar, Ahmad1 aKrishnamurty, Sailaja1 aDar, Manzoor, Ahmad uhttp://library.ncl.res.in/content/first-principles-investigation-electrocatalytic-reduction-co2-zirconium-based-single-double02607nas a2200253 4500008004100000022001400041245013800055210006900193260000900262300001100271490000800282520169600290653001901986653002502005653001602030653001402046653002802060100002902088700002902117700002702146700002902173700002602202856012502228 2022 eng d a0927-775700aFree base phthalocyanine coating as a superior corrosion inhibitor for copper surfaces: a combined experimental and theoretical study0 aFree base phthalocyanine coating as a superior corrosion inhibit cSEP  a1291380 v6483 a

In the quest of novel, eco-benign copper corrosion inhibitors, free base and a set of six metal Phthalocyanine (Pc) coatings (where metal is Zn, Cu, Fe, Co, Ni, Mn) are systematically evaluated for their corrosion inhibition efficiency. The study demonstrates that the free base Phthalocyanine coatings are superior corrosion inhibitors for Cu surface in HCl with a corrosion inhibition efficiency of 88% as compared to its metal counterparts. A detailed and indepth study involving concerted electrochemical polarisation, impedance measurements at various concentrations of HCl assert the superior corrosion inhibition efficiency of free base Pc coatings as compared to its metal counterparts. Underlying factors/interface chemistry contributing to it is brought out using first principle based studies. First principles based computational studies establish that superior corrosion inhibition ability of free base phthalocyanine molecule is attributed to its innate binding ability with copper surface and its better inter-molecular packing. Thus, the theoretical adsorption trends of various studied phthalocyanine molecules while clearly following the experimental corrosion inhibition efficiency trends undermine the importance of contribution of chelating factors for the formation of a stable and efficient corrosion inhibition coating on a surface and that the adhesion/adsorption strength of a molecule correlates directly to its corrosion inhibition efficiency. The experimental observations are further substantiated through FE-SEM, EDAX and XPS studies. The corrosion inhibition efficiency of free base phthalocyanine is followed by its zinc based counterpart at 85%.

10aCopper surface10aCorrosion inhibitors10aDFT studies10aImpedance10aPhthalocyanine coatings1 aSamal, Pragnya, Paramita1 aDekshinamoorthy, Amuthan1 aArunachalam, Shivakami1 aVijayaraghavan, Saranyan1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/free-base-phthalocyanine-coating-superior-corrosion-inhibitor-copper-surfaces-combined00901nas a2200229 4500008004100000022001400041245012500055210006900180260000800249300001100257490000700268653001900275653005600294653002600350653004300376653003000419653002600449100001900475700002600494700002700520856012400547 2022 eng d a2296-264600aFrom ``Cosmic Cooking'' to chemistry of the future: a collective dialogue on chemistry as a tribute to Prof. Sourav Pal.0 aFrom Cosmic Cooking to chemistry of the future a collective dial cAPR a9081650 v1010acosmic cooking10acoupled cluster and density functional calculations10adialogue on chemistry10apincers porphyrinoids and oxometalates10asmall molecule activation10aTheoretical chemistry1 aRoy, Soumyajit1 aKrishnamurty, Sailaja1 aSchoefberger, Wolfgang uhttp://library.ncl.res.in/content/cosmic-cooking-chemistry-future-collective-dialogue-chemistry-tribute-prof-sourav-pal01548nas a2200193 4500008004100000022001400041245011000055210006900165260000900234300001600243490000700259520084100266100002301107700002901130700002101159700002601180700002801206856012001234 2022 eng d a0022-326300aLewis acid-catalyzed chemodivergent and regiospecific reaction of phenols with quaternary peroxyoxindoles0 aLewis acidcatalyzed chemodivergent and regiospecific reaction of cNOV  a14155-141670 v873 a

The indium-catalyzed regiospecific coupling of substituted phenol derivatives and quaternary peroxyoxindoles for the synthesis of C2 or C4 benzoxazin-3-one-substituted phenols via skeletal rearrangement is described. This reaction is demonstrated with 17 examples with good yields and diverse aryl substituents. In contrast to the indium-catalyzed reaction, the Cu(OTf)2- catalyzed reaction of the phenol with quaternary peroxyoxindoles afforded C2 or C4 2-oxindole-substituted phenol derivatives. This diverse catalytic reaction generated various biologically important phenol-substituted 2-oxindole derivatives directly without any skeleton rearrangement and was demonstrated with 19 examples in high yield. The regiospecificity and the reaction pathways were explained with the support of density functional theory (DFT).

1 aShaikh, Moseen, A.1 aSamal, Pragnya, Paramita1 aUbale, Akash, S.1 aKrishnamurty, Sailaja1 aGnanaprakasam, Boopathy uhttp://library.ncl.res.in/content/lewis-acid-catalyzed-chemodivergent-and-regiospecific-reaction-phenols-quaternary01581nas a2200193 4500008004100000022001400041245013600055210006900191260000900260300001400269490000600283520085800289100002101147700003001168700001601198700002201214700002601236856012501262 2022 eng d a2470-134300aMapping the finite-temperature behavior of conformations to their potential energy barriers: case studies on Si6B and Si5B clusters0 aMapping the finitetemperature behavior of conformations to their cFEB  a6167-61730 v73 a

Dynamical simulations of molecules and materials have been the route to understand the rearrangement of atoms within them at different temperatures. Born-Oppenheimer molecular dynamical simulations have further helped to comprehend the reaction dynamics at various finite temperatures. We take a case study of Si6B and Si5B clusters and demonstrate that their finite-temperature behavior is rather mapped to the potential energy surface. The study further brings forth the fact that an accurate description of the dynamics is rather coupled with the accuracy of the method in defining the potential energy surface. A more precise potential energy surface generated through the coupled cluster method is finally used to identify the most accurate description of the potential energy surface and the interconnected finite-temperature behavior.

1 aManeri, Asma, H.1 aSingh, Chandrodai, Pratap1 aKumar, Ravi1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/mapping-finite-temperature-behavior-conformations-their-potential-energy-barriers-case02498nas a2200241 4500008004100000022001400041245010600055210006900161260000900230300001100239490000800250520167900258653001101937653000801948653004201956653002301998653002102021100002402042700003002066700002602096700001702122856011702139 2022 eng d a0014-305700aStructure-property insights into chiral thiophene copolymers by direct heteroarylation polymerization0 aStructureproperty insights into chiral thiophene copolymers by d cDEC  a1116760 v1813 a

Chiral thiophene copolymers with fluorene as co monomer are designed having N-Boc-L-glutamic acid-1-tert-butyl ester as a chiral substituent located either on the thiophene unit or the fluorene unit with varying spacer length. The atom-economic direct heteroarylation polymerization (DHAP) method is utilized for the polymerization. Gibb's free energy (delta G) for polymerization determined using DFT calculations indicate difficulty in achieving high molar mass when the bulky chiral substituents are attached through short spacer to the backbone. The experimental observations are in agreement with the theoretical calculations with no polymer-ization or very low molar mass sticky compounds obtained for reactions with predicted + & UDelta;G values. Structure -property relationship are compared for two chiral polymers -P4 and P5 having the chiral substitution on thiophene and fluorene units respectively. No CD signal is observed in THF-a good solvent where the polymers are molecularly dissolved. Intense bisignated CD signal is observed for both polymers upon addition of methanol - a poor solvent, to their THF solution. The bisignate CD signal with maxima at lower wavelength and inflection point associated with the pi-pi* absorption band is characteristic of exciton coupling between polymer chains in a left handed helical orientation. Small differences are observed in the intensity of the CD signal for the polymers P4 and P5 highlighting the impact of steric hindrance of bulky pendant groups on polymer conformation. DHAP is an atom economic polymerization procedure that can be gainfully utilized for developing chiral conjugated polymers.

10achiral10aDFT10aDirect heteroarylation polymerization10aGibb?s free energy10aSteric Hindrance1 aNikam, Shrikant, B.1 aSingh, Chandrodai, Pratap1 aKrishnamurty, Sailaja1 aAsha, S., K. uhttp://library.ncl.res.in/content/structure-property-insights-chiral-thiophene-copolymers-direct-heteroarylation01802nas a2200205 4500008004100000022001400041245011200055210006900167260000900236300001600245490000700261520105300268653002601321653002301347653002201370653002001392100003001412700002601442856012801468 2022 eng d a0360-319900aSynergetic storage of ammonia over Al quantum dots embedded graphene sheets: a first principles perspective0 aSynergetic storage of ammonia over Al quantum dots embedded grap cOCT  a36873-368850 v473 a

In view of the increasing energy demand and global warming, it is imperative to search for a renewable and environmental friendly fuel in lieu of non-renewable energy resources. Hydrogen stands out to be the best fuel as both, renewable and clean. Concerning the use of hydrogen as a fuel, its production as well as storage are current global challenges being worked on. In this article, a density functional theory based study is performed to identify the potential of supported Al cluster cages for ammonia storage. In this context, initially, stability of pristine and doped aluminum nanoclusters anchored on graphene sheet is evaluated following which thus supported stable nanoclusters are studied for the adsorption of NH3 to identify their storage capacity. For both, complexes and NH3 adsorbed complexes, Density of States (DOS), Charge Density Difference (CDD) and Bader charge analysis is done to understand their electronic properties.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

10aAluminum nanoclusters10aDefective graphene10aEndohedral doping10aNH 3 adsorption1 aSingh, Chandrodai, Pratap1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/synergetic-storage-ammonia-over-al-quantum-dots-embedded-graphene-sheets-first-principles02240nas a2200217 4500008004100000022001400041245016500055210006900220260000900289300001200298490000700310520143100317100002001748700001601768700001701784700002201801700002001823700002601843700002401869856012901893 2022 eng d a2044-475300aTantalum based single, double, and triple atom catalysts supported on g-C2N monolayer for effective nitrogen reduction reaction: a comparative DFT investigation0 aTantalum based single double and triple atom catalysts supported cJAN  a310-3190 v123 aDesign of efficient and low cost electrocatalysts for the reduction of N-2 molecule to NH3 in a green manner remains a great challenge in the 21st century. Herein, we have used density functional theory based first principle simulations to systematically investigate the nitrogen reduction reaction (NRR) ability of single, double, and triple Ta-atom catalysts anchored to C2N monolayer. Our results demonstrate that the single and triple Ta-atom catalysts anchored to C2N monolayer act as superior catalysts for the NRR via alternating and distal pathways as compared to the Ru(0001) stepped surface. In particular, the triple Ta-atom catalyst anchored to C2N shows enhanced NRR performance with a limiting potential of -0.72 V which is comparable to the experimentally reported Ru based single atom catalyst. Further, all the three catalysts were found to be highly selective for NRR with an enhanced ability to suppress the competitive hydrogen evolution reaction. Electronic structure analysis revealed that the enhanced ability of Ta-3@C2N catalyst to effectively capture and reduce N-2 molecule could be attributed to the built up of localized d states near the fermi level, thereby aiding in strong electron transfer into the antibonding orbitals of N-2. Thus, our findings propose a highly active catalyst for the NRR with an emphasis on the importance of triple atom-based catalysts for electrocatalytic applications.1 aRasool, Anjumun1 aAnis, Insha1 aDixit, Mudit1 aMaibam, Ashakiran1 aHassan, Afshana1 aKrishnamurty, Sailaja1 aDar, Manzoor, Ahmad uhttp://library.ncl.res.in/content/tantalum-based-single-double-and-triple-atom-catalysts-supported-g-c2n-monolayer-effective02342nas a2200229 4500008004100000022001400041245011800055210006900173260000800242490000700250520149600257653002801753653001901781653002801800653002101828653003201849100002501881700002901906700002701935700002601962856012401988 2023 eng d a1439-423500aCan Li atoms anchored on boron- and nitrogen-doped graphene catalyze dinitrogen molecules to ammonia? a DFT study0 aCan Li atoms anchored on boron and nitrogendoped graphene cataly cJUN0 v243 a

The most successful electrochemical conversion of ammonia from dinitrogen molecule reported to date is through a Li mediated mechanism. In the framework of the above fact and that Li anchored graphene is an experimentally feasible system, the present work is a computational experiment to identify the potential of Li anchored graphene as a catalyst for N-2 to NH3 conversion as a function of (a) minimum number of Li atoms needed for anchoring on graphene sheets and (b) the role of chemical modification of graphene surfaces. The studies bring forth an understanding that Li anchored graphene sheets are potential catalysts for ammonia conversion with preferential adsorption of N-2 through end-on configuration on Li atoms anchored on doped and pristine graphene surfaces. This mode of adsorption being characteristic of Nitrogen Reduction Reaction (NRR) through enzymatic pathway, examination of the same followed by analysis of electronic properties demonstrates that tri-Li atoms (Tri Atom Catalysts, TACs) are more efficient as catalysts for NRR as compared to two Li atoms (Di Atom Catalysts, DACs). Either way, the rate determining step was found to be *NH2 ->*NH3 step (mixed pathway) with Delta G(max)=1.02 eV and *NH2-*NH3 ->*NH2 step (enzymatic pathway) with Delta G(max)=1.11 eV for 1B doped TAC and DAC on graphene sheet, respectively. Consequently, this work identifies the viability of Li anchored graphene based 2-D sheets as hetero-atom catalyst for NRR.

10acomputational chemistry10aGraphene Sheet10aheterogeneous catalysis10aLi Nanoparticles10aNitrogen Reduction Reaction1 aVerma, Tushar, Singh1 aSamal, Pragnya, Paramita1 aSelvaraj, Kaliaperumal1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/can-li-atoms-anchored-boron-and-nitrogen-doped-graphene-catalyze-dinitrogen-molecules01681nas a2200205 4500008004100000022001400041245011900055210006900174260000800243300001400251490000700265520092200272100002101194700002901215700002501244700002301269700002601292700002801318856012901346 2023 eng d a0022-326300aCatalyst-assisted selective vinylation and methylallylation of a quaternary carbon center using tert-butyl acetate0 aCatalystassisted selective vinylation and methylallylation of a  cJUL a9686-97030 v883 a

The In-(OTf)(3)-catalyzed & alpha;-vinylationof varioushydroxy-functionalized quaternary carbon centers using in situ generatedisobutylene from tert-butyl acetate is presentedas a novel synthetic methodology. Moreover, tert-butylacetate is a nonflammable feed stock and is a readily available sourcefor the in situ production of vinyl substituents, as demonstratedby the vinylation reaction with quaternary hydroxy/methoxy compounds.Moreover, an excellent selectivity for methylallylation over vinylationwas obtained with Ni-(OTf)(2) as a catalyst. In the case ofperoxyoxindole, methylallyl-functionalized 1,4-benzoxazin-3-one derivativeswere formed through the sequential rearrangement of peroxyoxindolefollowed by the nucleophilic attack by isobutylene. The detailed mechanismfor this reaction and rationalization for the selectivity are providedusing kinetics and density functional theory studies.

1 aMohanta, Nirmala1 aSamal, Pragnya, Paramita1 aPandey, Akanksha, M.1 aMondal, Shankhajit1 aKrishnamurty, Sailaja1 aGnanaprakasam, Boopathy uhttp://library.ncl.res.in/content/catalyst-assisted-selective-vinylation-and-methylallylation-quaternary-carbon-center-using02387nas a2200301 4500008004100000022001400041245012100055210006900176260000800245300001600253490000700269520134900276653002001625653002001645653002901665653003601694653002701730653003201757100001901789700002201808700002401830700002601854700001901880700002601899700001901925700001601944856012501960 2023 eng d a1944-824400aChemical bridge-mediated heterojunction electron transport layers enable efficient and stable perovskite solar cells0 aChemical bridgemediated heterojunction electron transport layers cJUN a29597-296080 v153 a

Perovskite solar cells (PSCs) emerged as potential photovoltaicenergy-generating devices developing in recent years because of theirexcellent photovoltaic properties and ease of processing. However,PSCs are still reporting efficiencies much lower than their theoreticallimits owing to various losses caused by the charge transport layerand the perovskite. In this regard, herein, an interface engineeringstrategy using functional molecules and chemical bridges was appliedto reduce the loss of the heterojunction electron transport layer.As a functional interface layer, ethylenediaminetetraacetic acid (EDTA)was introduced between PCBM and the ZnO layer, and as a result, EDTAsimultaneously formed chemical bonds with PCBM and ZnO to serve asa chemical bridge connecting the two. DFT and chemical analyses revealedthat EDTA can act as a chemical bridge between PCBM and ZnO, passivatedefect sites, and improve charge transfer. Optoelectrical analysisproved that EDTA chemical bridge-mediated charge transfer (CBM-CT)provides more efficient interfacial charge transport by reducing trap-assistedrecombination losses at ETL interfaces, thereby improving device performance.The PSC with EDTA chemical bridge-mediated heterojunction ETL exhibiteda high PCE of 21.21%, almost no hysteresis, and excellent stabilityto both air and light.

10acharge transfer10achemical bridge10aelectron transport layer10aethylenediaminetetraacetic acid10aPerovskite solar cells10atrap-assisted recombination1 aPatil, Pramila1 aMaibam, Ashakiran1 aSangale, Sushil, S.1 aMann, Dilpreet, Singh1 aLee, Hyun-Jung1 aKrishnamurty, Sailaja1 aKwon, Sung-Nam1 aNa, Seok-In uhttp://library.ncl.res.in/content/chemical-bridge-mediated-heterojunction-electron-transport-layers-enable-efficient-and02218nas a2200229 4500008004100000022001400041245011500055210006900170260000800239300001100247490000800258520137100266653001501637653003101652653003001683653003001713653003101743100002701774700003001801700002601831856013101857 2023 eng d a0169-433200aChemically modified graphene sheets as potential sensors for organophosphate compounds(pesticide): A DFT study0 aChemically modified graphene sheets as potential sensors for org cMAY a1567450 v6193 a

Owing to the extensive use of pesticides in agriculture and the threat posed to the environment and humankind, attention is drawn toward the need for its remediation from various sources, in particular from water. The adsorption characteristics of hydrophobic graphene and its BN doped counterparts are evaluated using DFT methodology, to assess their sensing potential towards notable pesticide molecules (Organophosphate pesticides (OPs) such as chlorpyriphos, parathion, methyl-parathion, and fenitrothion). To accomplish this, various elec-tronic properties such as band structure, DOS, Bader charge analysis, and CDD have been calculated. Interest-ingly, exothermic interactions (-0.1 eV to-2 eV) have been noted for all the OPs with NB doped single vacancy defect induced graphene surfaces. With an exception of FTN, all the other OPs showed significant changes in the electronic properties of surfaces as apparent from the change in band gap and nature of the band from indirect to direct. The appreciable adsorption energy, higher charge transfer, and notable variation in the band gap are the decisive factors behind the strong interaction exhibited by NB doped surfaces especially dg-(NB-2)2 (except FTN). These findings demonstrate the suitability of NB doped single vacancy defect induced graphene sheets for the detection of the studied OPs.

10aAdsorption10aBN doped graphene surfaces10aCharge density difference10aDensity functional theory10aOrganophosphate pesticides1 aShivankar, Bhavana, R.1 aSingh, Chandrodai, Pratap1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/chemically-modified-graphene-sheets-potential-sensors-organophosphate-compoundspesticide-dft02064nas a2200205 4500008004100000022001400041245009100055210006900146260000800215300001200223490000700235520134700242100002401589700002701613700002201640700002601662700003001688700002701718856011301745 2023 eng d a0031-865500aD-A-D-based unsymmetrical thiosquaraine dye for the dye-sensitized solar cells(dagger)0 aDADbased unsymmetrical thiosquaraine dye for the dyesensitized s cMAR a529-5370 v993 a

In dye-sensitized solar cell, modulating the electronic properties of the sensitizer by varying the donor, pi-spacer, acceptor and anchoring groups help optimizing the structure of the dye for better device performance. Here, a donor-acceptor-donor-based unsymmetrical thiosquaraine sensitizer (SQ5S) has been designed and synthesized. Photophysical, electrochemical, theoretical and photovoltaic characterizations of SQ5S dye have been compared with its oxygen analog, SQ5. The incorporation of the sulfur atom in the acceptor unit of SQ5S dye showed an intense peak at 688 nm, which was 38 nm of red-shifted and showed the panchromatic light harvesting response with the onset of 850 nm compared with SQ5 dye. The LUMO and HOMO energy levels are well aligned with the conduction band of TiO2 and the redox potential of electrolyte for the charge injection and the dye-regeneration processes, respectively. Photovoltaic efficiency of 1.51% (V-OC 610 mV, J(SC) 3.07 mA cm(-2), ff 81%) has been achieved for SQ5S dye, whereas SQ5 showed the device performance of 5.43% (V-OC 723 mV, J(SC) 9.3 mA cm(-2), ff 80%). The decreased device performance for the dye SQ5S has been attributed to the favorable intersystem crossing process associated with the photoexcited SQ5S that reduces the driving force for the charge injection process.

1 aJadhav, Avinash, P.1 aSingh, Ambarish, Kumar1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttp://library.ncl.res.in/content/d-d-based-unsymmetrical-thiosquaraine-dye-dye-sensitized-solar-cellsdagger01834nas a2200169 4500008004100000022001400041245012000055210006900175260000900244300001100253490000800264520119500272100002201467700002601489700002501515856012401540 2023 eng d a0169-433200aElectrocatalytic nitrogen reduction on defective graphene modulated from single atom catalyst to aluminium clusters0 aElectrocatalytic nitrogen reduction on defective graphene modula cJUN  a1570240 v6233 a

Density Functional Theory (DFT) investigation on the most earth-abundant Al-based catalysts, has been conducted detailing its electronic properties and catalytic efficacy for nitrogen reduction at ambient condition. The Al-based catalysts have been modulated to perform as par a highly performing, but rare, Ru-single atom catalytic center by varying number of Al atoms, shape, and size. The coalesce of band-center, work function and electronic properties in metal atom catalysts along with N-N bond activation has been demonstrated to be responsible for an efficient nitrogen reduction reaction (NRR) with Delta Gmax of 0.78 eV in Al5 supported on N-doped double vacancy graphene (Al5@N4-DVG) catalyst. Electron localization function analysis has shown a weak physisorption of N2 in the Al-based catalysts. Projected Density of States (PDOS) illustrates the enhancement of aluminium electron density in Al5@N4-DVG led to enhanced orbital densities overlap of Alp and Np electrons. The Bader charge analysis and electronic analysis of the intermediates show efficient electron gain on the N atoms, leading to formation of NH3 from the NxHy intermediates in Al5@N4-DVG catalyst.

1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja1 aBabaRao, Ravichandar uhttp://library.ncl.res.in/content/electrocatalytic-nitrogen-reduction-defective-graphene-modulated-single-atom-catalyst02280nas a2200241 4500008004100000022001400041245009800055210006900153260000800222300001100230490000800241520142300249653001901672653003601691653003101727653002401758653002301782653002301805100002901828700003001857700002601887856012501913 2023 eng d a0169-433200aExpounding lemonal terpenoids as corrosion inhibitors for copper using DFT based calculations0 aExpounding lemonal terpenoids as corrosion inhibitors for copper cMAR a1560660 v6143 a

The most important bottleneck in identifying an innovative and yet viable corrosion inhibitor for copper surfaces is discerning the chemical interactions at the interface of adsorbate and adsorbent. The present work, primarily, discerns the interface chemistry of green corrosion inhibitors, viz., lemonal terpenoids, with the copper surfaces for the first time. The interface chemistry is evaluated for distinct facets of copper, modelled by periodic surfaces to finite sized aggregates, with two stereoisomers viz., citral and neral through density functional calculations. The adsorption/ interaction properties between the surface and the corrosion inhibiting molecule are analysed through the electronic properties such as density of states, charge density difference plots and Bader charges where in distinct bonding mechanisms are identified as a function of varying facets. Apart from the adsorption properties, molecular packing properties are of paramount importance towards the design of an efficient corrosion inhibitor for a surface. Hence, we also analyse the intermolecular stacking energies between the inhibitors when packed among themselves in vacuum and when adhered on to metal surfaces. The studies bring forth an understanding that lemon terpenoids are highly potential corrosion inhibitors for copper surfaces, particularly, for Cu (110) surfaces both in neutral and protonated form.

10aCopper surface10aDensity Functional Theory (DFT)10aGreen corrosion inhibitors10aInterface chemistry10aLemonal terpenoids10aMolecular stacking1 aSamal, Pragnya, Paramita1 aSingh, Chandrodai, Pratap1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/expounding-lemonal-terpenoids-corrosion-inhibitors-copper-using-dft-based-calculations01177nas a2200253 4500008004100000022001400041245008400055210006900139260000800208300001200216490000800228520038000236653000600616653002400622653001000646653001900656653001800675653001900693100002100712700002700733700002600760700002800786856010900814 2023 eng d a1615-415000aFeCl2-catalyzed rearrangement of aryl peroxyoxindole into 1,3-benzooxazin-4-One0 aFeCl2catalyzed rearrangement of aryl peroxyoxindole into 13benzo cFEB a515-5210 v3653 a

We report an FeCl2-catalyzed radical rearrangement of aryl peroxyoxindoles into 1,3-benzooxazin-2-ones to obtain a variety of aryl substituted 1,3-benzooxazin-4-ones in moderate to good yields. Mechanistically, this skeletal rearrangement of peroxyoxindoles proceeded via radical pathway and was well supported with a series of experimental findings and DFT studies.

10a110a3-Benzooxazin-4-one10aFeCl210aPeroxyoxindole10arearrangement10aRing expansion1 aMohanta, Nirmala1 aSamal, PragnyaParamita1 aKrishnamurty, Sailaja1 aGnanaprakasam, Boopathy uhttp://library.ncl.res.in/content/fecl2-catalyzed-rearrangement-aryl-peroxyoxindole-13-benzooxazin-4-one02387nas a2200229 4500008004100000022001400041245016600055210006900221260000900290300001100299490000800310520155500318653002201873653002701895653002201922653001601944653001101960100001801971700001901989700002602008856012302034 2023 eng d a0169-433200aFunctionalized Mo2BX2 (X = H, OH, O) MBenes as a promising sensor, capturer and storage material for environmentally toxic gases: A case study of 1T and 2H phase0 aFunctionalized Mo2BX2 X H OH O MBenes as a promising sensor capt cAPR  a1562990 v6153 a

MBenes analogous to MXenes, exfoliated from the bulk MAB phase (M = transition metal, A = IIIA and IVA group, and B = boron) have appeared as promising two dimensional (2D) materials due to their intriguing properties. Here, we report the 2D 1T-2H-phase of Mo2B with their functionalized derivatives Mo2BX2 (X= H, OH, O) and investigate their structural, electronic, and adsorption behavior of toxic gases using the first-principles calculations. This study finds that pristine and functionalized MBenes have dynamic and thermal stability and possess metallic nature in both phases. Based on adsorption behavior and comparison with other 2D materials, we find that pristine MBenes are a desirable adsorbent for NO2, SO2, and CO2 capture. In contrast, the moderate adsorption energies for functionalized MBenes-NH3 systems reveal good sensitivity for NH3 gas detection in both phases. In particular, 2H-Mo2BH2 has higher CT (-0.11e) and appropriate adsorption energy (-0.30 eV), leads a shorter recovery time. Further, DOS calculations reveal that the electrical conducting behavior of MBenes makes them suitable for NH3 detection with a short recovery time. Our results would provide the first insight into the surface-functionalized effect on the structural and electronic properties of the MBenes, and shed light on the application of MBenes for the sensing and catalyst of typical toxic and greenhouse gases, respectively.

10aAdsorption energy10aFirst-principles study10aFunctionalization10aGas sensing10aMBenes1 aShukla, Aarti1 aSharma, Gautam1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/functionalized-mo2bx2-x-h-oh-o-mbenes-promising-sensor-capturer-and-storage-material02737nas a2200289 4500008004100000022001400041245016500055210006900220260000800289300001100297490000700308520168400315653002501999653003302024653002402057653004502081653003402126653002702160100002002187700002202207700001902229700001702248700002202265700002602287700000502313856012902318 2023 eng d a2352-152X00aHigh rate, high temperature, dendrite free plating/stripping of Li in 3-dimensional honeycomb boron carbon nitride to realize an ultrastable lithium metal anode0 aHigh rate high temperature dendrite free platingstripping of Li  cSEP a1075470 v683 a

Lithium (Li) metal could be the anode of choice for energy dense Li-batteries owing to its high theoretical specific capacity. However, low coulombic efficiency and poor safety on account of the occurrence of the Li-dendrites during charging-discharging pose a bottleneck for practical applications. In this work, we report a high-rate plating and stripping of Li through host engineering to realize ultrastable Li metal anode (LMA). Benchmark plating/stripping efficiency could be achieved via uniquely structured, highly ordered honeycomb boron carbon nitride (HBCN) as a functional scaffold. Boron and nitrogen doping, large surface area and ordered mesoporous structure induce homogeneous solid electrolyte interface (SEI) layer formation and provide numerous nucleation sites with subsequent dendrite-free growth with 99.98 % coulombic efficiency at 8 mA cm(-2) high current and 10 mAh cm(-2) capacity over 3000 cycles. Via post-cycling advanced characterizations techniques of Ex-situ XPS, 3D X-ray micro-tomography analyses and FESEM, we demonstrate the formation of a stable SEI layer and morphological changes that occurred during Li plating cycles in the HBCN structure. Computational studies validate the high lithium plating-stripping efficacy of HBCN to its highly ordered porous nature, exothermic Li-binding and upshift in the Fermi levels. When tested at elevated temperature (50 degrees C), a stable Li plating-stripping in HBCN is realised at 4 mA cm(-2) current and 10 mAh cm(-2) capacity values with similar to 100 % C.E. Furthermore, we report the results of testing a Li metal cell comprised of Li deposited HBCN anode and LiFePO4 (LFP) cathode.

10aBoron carbon nitride10aDendrite-free Li metal anode10aFunctional scaffold10aHigh temperature plating/stripping of Li10aMolecular planarity parameter10aX-ray micro-tomography1 aPatrike, Apurva1 aKarbhal, Indrapal1 aWasnik, Kundan1 aTorris, Arun1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja1 a uhttp://library.ncl.res.in/content/high-rate-high-temperature-dendrite-free-platingstripping-li-3-dimensional-honeycomb-boron02600nas a2200241 4500008004100000022001400041245018300055210006900238260000800307300001100315490000800326520170900334653002002043653002502063653002702088653002102115653001302136100002002149700001602169700001802185700002602203856012902229 2023 eng d a1387-181100aInsights into adsorption of various gases on extra-framework cations of zeolite: a dispersion corrected DFT study on zeolite cluster models with Li plus , Na plus and K plus ions0 aInsights into adsorption of various gases on extraframework cati cNov a1127390 v3613 a

Design of an economical and sustainable gas separation material is relevant in several industrial processes. Zeolites with tunable pore sizes are ideal molecular sieves of many gases. The adsorption centers of these molecular sieves are extra-framework Lewis acid centers. In this study, we attempt to delineate the electronic properties of such centers (Li+, Na+ and K+) and their sorption properties towards N2, O2, CO, CO2 and H2. Negative framework of zeolites are modeled using different cluster models that present distinct electronic environment and role of this environment on the Lewis acidity of the cation. The sorption property towards different gases is evaluated using dispersion corrected DFT studies. The results obtained are benchmarked for one of the studied model using CCSD calculations. The results indicate that while the local environment modulates the adsorption properties, the relative adsorption properties between different ions follow the same order irrespective of the type of negative framework modeled. This reveals that intrinsic atomic properties of the charge compensating cations drive the sorption properties of the zeolites. Adsorption energies compounded with the analysis of IR stretching frequencies of the adsorbed gases reveals that Li centers shows molecular adsorption (charge donation to the cationic centers) towards N2 as compared to O2 and towards CO2/CO as compared to H2, demonstrating the applicability of Li-Zeolites as ideal membranes for oxygen concentrators and syngas separation. These adsorption studies are ratified by the BOMD simulations at 300 K, where H2 and O2 desorbs while N2, CO and CO2 remains adsorbed to the cationic site.

10aBOMD simulation10aCO/CO2/H2 separation10aExtra-framework cation10aN2/O2 separation10azeolites1 aDevasia, George1 aKumar, Ravi1 aVaval, Nayana1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/insights-adsorption-various-gases-extra-framework-cations-zeolite-dispersion-corrected-dft02030nas a2200217 4500008004100000022001400041245018000055210006900235260000900304490000700313520118900320653002901509653001601538653002001554653001301574100002501587700003001612700002601642700002001668856012401688 2023 eng d a1861-472800aInvestigation of the effect of zeolite supports and the role of W-species for one-pot catalytic conversion of cellulose to ethylene glycol: theoretical & experimental studies.0 aInvestigation of the effect of zeolite supports and the role of  cFEB 0 v183 a

Endeavors were made to study the influence of various zeolite (HY, NaY, NaZSM-5 and HZSM-5) supports with (Al)-Ni-W metal combination catalysts for the ethylene glycol (EG) production, selectively from cellulose. From the experimental results ZSM-5 (NaZSM-5/73.3% & HZSM-5/67.7%) support is superior over HY & NaY support in selective EG production from cellulose. It was understood that W- species with oxygen vacancies (WO3-x, XPS analysis) plays an important role in producing the glycolaldehyde (GA) intermediate (via C-C cleavages), which on hydrogenation over Ni- sites selectively produce EG. Further, the studies based on the Density Functional Theory (DFT) were conducted to substantiate the involvement of the WO3-x species in the reaction. The adsorption energies and structural changes establish that the C-2-C-3 bond of the glucose elongates and thereby activates on adsorbing to WO3-x sites supporting the formation of GA. Activation of GA on Ni- sites is distinguished by an increase of 0.1 angstrom in C=O bond length, which facilitates the hydrogenation of C=O resulting in EG. The reaction pathway is explained through an analysis of CDD and DOS.

10aCellulose hydrogenolysis10aDFT studies10aethylene glycol10azeolites1 aSreekantan, Sreejith1 aSingh, Chandrodai, Pratap1 aKrishnamurty, Sailaja1 aMarimuthu, Banu uhttp://library.ncl.res.in/content/investigation-effect-zeolite-supports-and-role-w-species-one-pot-catalytic-conversion02479nas a2200325 4500008004100000245010800041210006900149260000800218300001400226490000600240520139800246653001601644653002401660653002601684653002301710653001501733653001701748100002101765700002601786700002901812700002901841700002501870700002601895700002101921700002201942700001601964700002601980700002602006856012102032 2023 eng d00aMnXWO4 nanostructure-based catalysts for single-step oxidation of cyclohexane and methane to oxygenates0 aMnXWO4 nanostructurebased catalysts for singlestep oxidation of  cAPR a7245-72580 v63 a

Activation of the C-H bond in cyclohexane (CYH) and methane is a crucial step to obtain desirable oxygenated products using nanostructured catalyst and is a great challenge and an efficient route to mitigate the inauspicious effects of climate change. The active sites were identified using XRD, HR-TEM, SEM, N2 sorption analysis, TPR, Raman, XPS, TGA, in situ DRIFT, XAS, etc. In optimal reaction conditions, 46% of CYH was converted into adipic acid (AA) on MnxWO4 nanostructures within 6 h. The recyclability test confirmed the catalyst heterogeneity, which revealed no appreciable loss of catalytic activity even after three consecutive reactions. In situ DRIFT study reveals that CYH is oxidized to cyclohexanone and cyclohexanol (KA oil) and is further oxidized to AA via carboxylate intermediates. DFT studies disclosed that MnOx species are responsible for the C-H activation of CYH, and the Mn2+/Mn3+ redox centers play a vital role in the absorption of KA oil to form AA. Herein, we demonstrated the significant role of the ``MnOx'' species and that adequate Lewis and Bronsted acidic sites, redox centers of (Mn2+/Mn3+), and lattice oxygen are accountable for the CYH conversion toward the AA. Additionally, we have reported the oxidation of methane to methanol (146 mu mole per gram of catalyst) in the presence of water at 75 degrees C without over-oxidation products.

10aAdipic Acid10aC-H bond activation10aCyclohexane oxidation10amethane activation10aMnOx chain10aRedox center1 aPrabu, Marimuthu1 aManikandan, Marimuthu1 aSamal, Pragnya, Paramita1 aGurrala, Lakshmi, Prasad1 aMekala, Siva, Prasad1 aArchana, Ramakrishnan1 aNayak, Chandrani1 aBhattacharyya, D.1 aJha, S., N.1 aKrishnamurty, Sailaja1 aRaja, Thirumalaiswamy uhttp://library.ncl.res.in/content/mnxwo4-nanostructure-based-catalysts-single-step-oxidation-cyclohexane-and-methane02861nas a2200205 4500008004100000022001400041245009900055210006900154260000800223300001600231490000700247520213700254100002402391700002602415700002202441700002202463700002602485700001702511856012702528 2023 eng d a1463-907600aQuantum dot (Aun/Agn, n=3-8) capped single lipids: interactions and physicochemical properties0 aQuantum dot AunAgn n38 capped single lipids interactions and phy cAUG a22294-223030 v253 a

Realizing the potential of nano-hybrid biomaterials in various applications (nanoprobes to drug delivery), special attention has been devoted towards their synthesis and development. Nonetheless, several questions pertaining to the interface chemistry between the constituent entities (biomolecules and organic/inorganic part) of these hybrids, still remain unresolved. Keeping these unsolved issues in mind, the present theoretical investigation focuses on determining the electronic/physicochemical properties and interactions within gold and silver quantum dot-capped single lipid molecules. Quantum dots of varying sizes and shapes have been chosen and then coupled with lipid molecules (1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol, sodium salt (DMPG)), at the choline/glycerol, carboxylate and phosphate site. It has been identified that Au Qds interact strongly as compared to Ag clusters. In addition to the type, the shape and size of the Qd also influences their attachment with lipids. Among various sites, the phosphate site provides a considerably stronger platform for the coupling of Qds. On the other hand, attachment at the choline site leads to significantly lower interaction energies. The trend noted in interaction energies coincides with the structure-electronic property analysis (interatomic bond distances, charge transfer, PO2- stretching frequencies), which further helps in deducing the nature of interactions. The molecular dynamics simulations performed on selected Qd-lipid complexes established that the Qd interacting with lipids at the phosphate site remains fairly stable at room temperature without undergoing fragmentation into individual components. On the other hand, at the choline site, the Qd-to-lipid coupling is unstable and therefore they experience disintegration at 300 K temperature. Additionally, a unique glycerol-to-phosphate site crossover is evidenced, which reaffirms that the phosphate site is selectively preferred by Qds for binding with lipid molecules.

1 aManeri, Asma, H. H.1 aVarode, Shruti, Suhas1 aMaibam, Ashakiran1 aRanjan, Priyatosh1 aKrishnamurty, Sailaja1 aJoshi, Krati uhttp://library.ncl.res.in/content/quantum-dot-aunagn-n3-8-capped-single-lipids-interactions-and-physicochemical-properties01926nas a2200169 4500008004100000022001400041245009000055210006900145260000800214300001600222490000600238520133100244100002401575700002601599700001701625856011401642 2023 eng d a2470-134300aUnderstanding the stability of an unprecedented Si-Be bond within quantum confinement0 aUnderstanding the stability of an unprecedented SiBe bond within cAPR a14814-148220 v83 a

As of today, the Si-Be bond remains underexplored in the literature, and therefore its anomalous behavior continues to be an unsolved puzzle to date. Therefore, the present study aims at evaluating the integrity of an unprecedented Si-Be bond within quantum confinement. To accomplish this, first-principles-based calculation are performed on Be-doped silicon clusters with atomic sizes 6, 7, and 10. Silicon clusters are sequentially doped with one, two, and three Be atoms, and their thermal response is registered in the temperature range of 200-1500 K, which discloses several research findings. During the course of the simulations, the clusters face various thermal events such as solid cluster phase, rapid structural metamorphosis, and fragmentation. Si-Be nanoalloy clusters are noted to be thermally stable at lower temperatures (200-700 K); however, they begins to disintegrate earlier at a temperature as low as 800 K. This lower stability is attributed to the weak nature of Si and Be heteroatomic interactions, which is corroborated from the structural and electronic property analysis of the doped clusters. In addition to this, the performance of Be-doped clusters at finite temperatures is also compared with the thermal response of two other popular systems, viz., C-and B-doped silicon clusters.

1 aManeri, Asma, Harun1 aKrishnamurty, Sailaja1 aJoshi, Krati uhttp://library.ncl.res.in/content/understanding-stability-unprecedented-si-be-bond-within-quantum-confinement02181nas a2200229 4500008004100000022001400041245012100055210006900176260000800245300001200253490000700265520138100272653002501653653002101678653000801699653002201707653001501729100002401744700003001768700002601798856012701824 2023 eng d a0892-702200aUnderstanding the thermal stability of a 3d, 4d, and 5d element doped aluminium nanocluster through BOMD simulations0 aUnderstanding the thermal stability of a 3d 4d and 5d element do cFEB a245-2500 v493 a

Endohedrally doped atomic clusters have generated considerable interest among computational chemists on account of their tunable chemical properties that mimic a super atom. Such endohedrally doped clusters have also been experimentally realised in the more recent past. The present work explores the practical existence of 3d, 4d and 5d doped aluminium clusters, more specifically doped Al13 cluster, by evaluating systematically their structural stability through the first principle molecular dynamical simulations. Born-Oppenheimer Molecular Dynamics (BOMD) simulations have been carried out on Al12X atomic clusters where X = Ti, V, Fe, Co, Ni, Cu, Zn, Y, Mo, Ru, Rh and W are in endohedral position. The thermal stability of such endohedrally doped clusters is quantified through parameters such as delta(rms), MSD and is an element of(pro). Electronic structure calculations reveal that endohedral doping of only Rh, Cu and Zn is preferred in the Al-13 cluster. Other dopants prefer to remain on the surface positions. However, finite temperature calculations reveal that the Al12Zn cluster undergoes surface modifications from 300K leading to a distorted icosahedral structure. Al12Cu cluster in quartet spin state is the only thermally stable cluster with Cu remaining in the endohedral position and structure retaining icosahedral confirmation till 700K.

10aAl-13 atomic cluster10aBOMD simulations10aDFT10aEndohedral doping10asuper atom1 aSamudre, Nikhil, S.1 aSingh, Chandrodai, Pratap1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/understanding-thermal-stability-3d-4d-and-5d-element-doped-aluminium-nanocluster-through