00820nas a2200169 4500008004100000022001400041245013700055210006900192260007100261300001400332490000800346520014600354100002400500700002600524700001600550856008400566 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 uhttps://library.ncl.res.in/content/understanding-reactivity-properties-au-n-6-002601nas a2200217 4500008004100000022001400041245011400055210006900169260009200238300001200330490000700342520176600349653000802115653000902123653002802132653003302160100001902193700001602212700002602228856012902254 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 uhttps://library.ncl.res.in/content/understanding-molecular-conformations-na-dimyristoylphosphatidylglycerol-dmpg-using-dft-001795nas a2200169 4500008004100000022001400041245021300055210006900268260007100337300001400408490000800422520102600430100001701456700001601473700002601489856011001515 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 uhttps://library.ncl.res.in/content/understanding-site-selectivity-small-sized-neutral-and-charged-ain-4-002701nas a2200265 4500008004100000022001400041245016000055210006900215260000800284300001100292490000800303520172400311653003002035653003202065653001702097653001902114653003702133100002202170700001902192700001702211700002502228700002602253700002702279856012902306 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 uhttps://library.ncl.res.in/content/unravelling-distinct-surface-interactions-modified-graphene-nanostructures-methylene-blue03405nas a2200229 4500008004100000022001400041245021300055210006900268260000800337300001600345490000800361520247400369100002702843700002202870700003402892700001802926700001902944700002602963700003002989700002703019856012903046 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 uhttps://library.ncl.res.in/content/unsymmetrical-squaraine-dyes-dye-sensitized-solar-cells-position-anchoring-group-controls01927nas a2200169 4500008004100000022001400041245009000055210006900145260000800214300001600222490000600238520133100244100002401575700002601599700001701625856011501642 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 uhttps://library.ncl.res.in/content/understanding-stability-unprecedented-si-be-bond-within-quantum-confinement02182nas a2200229 4500008004100000022001400041245012100055210006900176260000800245300001200253490000700265520138100272653002501653653002101678653000801699653002201707653001501729100002401744700003001768700002601798856012801824 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 uhttps://library.ncl.res.in/content/understanding-thermal-stability-3d-4d-and-5d-element-doped-aluminium-nanocluster-through02578nas a2200217 4500008004100000022001400041245015200055210006900207260000800276490000700284520173800291653003002029653003702059653003002096653001702126100002502143700002202168700002602190700001802216856012602234 2024 eng d a0934-086600aUltra-small Au nanoclusters with tailored photoluminescence properties using modified thiol ligands: a computational and experimental demonstration0 aUltrasmall Au nanoclusters with tailored photoluminescence prope cOCT0 v413 a

Au nanoclusters with tailored photoluminescence can be obtained through controlled nanoparticle ligand interface chemistry. The present work reports molecular gold nanoclusters with tuneable photoluminescence emission from 600 to 700 nm using N,N `,N `'-trialkyl (11-mercaptoundecyl)ammonium chloride ligands as capping-agents. The tunability within red spectral region is regulated through specific interface chemistry between gold nanoclusters of molecular range and functional groups of the quaternary ammonium head over N,N `,N `'-trialkyl(11-mercaptoundecyl)ammonium chloride. Combined understanding obtained from the spectroscopy, microscopy, and density functional theory studies demonstrate that the functional group specific electronic interactions at the interfaces steer the emission characteristics of ``molecular'' Au nanoparticles. The study clearly identifies that bulkier functional groups, i.e., triethyl, tripropyl, tributyl, and dimethyl benzene over N+ (of thiol ligand) through their steric effects minimize the particle size giving rise to tunable photoluminescence emission in red spectral region. However, the red shift seen in the emission Au nanoclusters with N-(11-mercaptoundecyl)-N,N `-dimethylbenzenammonium chloride ligand in contradiction to particle size effect is computationally proved to be due to the delocalization of electron density from benzene aromatic ring to N+ of ammonium head leading to a reduction in the HOMO-LUMO energy gap. Fluorescence properties of water dispersible Au nanoclusters are tuned by varying the ammonium head group. Density Functional Theory studies correlate the distinction in emission when head group is phenyl to charge transfer characteristics. image

10aDensity functional theory10aphotoluminescent Au nanoclusters10asurface plasmon resonance10athiol ligand1 aChahande, Anurag, M.1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja1 aDevi, Nandini uhttps://library.ncl.res.in/content/ultra-small-au-nanoclusters-tailored-photoluminescence-properties-using-modified-thiol02418nas a2200277 4500008004100000022001400041245015000055210006900205260000800274300001400282490000700296520143000303653002501733653001401758653002101772653002701793653002601820653001401846100002201860700001801882700002201900700003501922700002601957700002501983856013202008 2025 eng d a1944-824400aUnlocking enhanced redox dynamics: the power of a bifunctional catalytic zinc phosphide interface in full cell and pouch lithium-sulfur batteries0 aUnlocking enhanced redox dynamics the power of a bifunctional ca cJAN a7657-76690 v173 a

Lithium-sulfur (Li-S) batteries face significant challenges, such as polysulfide dissolution, sluggish reaction kinetics, and lithium anode corrosion, hindering their practical application. Herein, we report a highly effective approach using a zinc phosphide (ZnP2) bifunctional catalyst to address these issues. The ZnP2 catalyst effectively anchors lithium polysulfides (LiPSs), catalytically reactivates them, and enhances lithium-ion diffusion. Utilizing a ZnP2-modified separator in a Li-S half-cell achieves an impressive initial capacity of 1145.4 mAh g-1, retaining 954 mAh g-1 and 99.8% Coulombic efficiency after 100 cycles, compared to the pristine separator. The underlying reaction mechanisms are thoroughly investigated through post-mortem analyses and density functional theory (DFT) calculations. Moreover, a Li-S full cell with an E/S ratio of 10 mu L mg-1 demonstrates stable cycling performance, achieving an initial capacity of 797.5 and 534 mAh g-1 after 100 cycles at 0.1C, with a negative-to-positive mass ratio of 3:1. Additionally, the real-world feasibility of lightweight and flexible Li-S pouch batteries with ZnP2-modified separators is explored, showing a stable performance over 100 cycles at 0.1C with 80% capacity retention. This engineered separator can be integrated with advanced sulfur cathodes to create high-energy-density, stable Li-S batteries for commercial applications.

10acatalytic interlayer10afull cell10alithium dendrite10alithium sulfur battery10apolysulfide shuttling10apouchcell1 aDas, Anoushka, K.1 aYadav, Poonam1 aVerma, Tushar, S.1 aMarulasiddappa, Thripuranthaka1 aKrishnamurty, Sailaja1 aShelke, Manjusha, V. uhttps://library.ncl.res.in/content/unlocking-enhanced-redox-dynamics-power-bifunctional-catalytic-zinc-phosphide-interface-full