@conference { ISI:000238284200016, title = {Density functional response approach for electric properties of molecules}, booktitle = {International Conference on Computational Methods in Sciences and Engineering (ICCMSE 2005)}, series = {LECTURE SERIES ON COMPUTER AND COMPUTATIONAL SCIENCES}, volume = {3}, year = {2005}, note = {International Conference on Computational Methods in Sciences and Engineering (ICCMSE 2005), Corinth, GREECE, OCT 21-26, 2005}, month = {OCT}, pages = {142-151}, publisher = {Vsp BV-C/o Brill Acad Publ, Po Box 9000, 2300 Pa Leiden, Netherlands}, organization = {Vsp BV-C/o Brill Acad Publ, Po Box 9000, 2300 Pa Leiden, Netherlands}, address = {Corinth, Greece}, abstract = {

We review in this paper an implementation of the response approach to the Kohn-Sham (KS) density functional theory (DFT) for obtaining the linear and non-linear electric response properties of molecules using Gaussian type orbital basis centered on atoms. We have made a formulation in which the response of the electron density through the solution of the coupled perturbed Kohn-Sham (CPKS) equations has to be obtained only once, instead of iteratively as in the case of completely analytic procedure. Our method is based on a numerical finite-field solution of derivative KS operator, followed by analytic solution of CPKS equation. Further, using the response of the electron density, the dipole moment, polarizability and first-hyperpolarizability of the molecules are evaluated. The method is particularly useful for large systems. We tested our method using HF, BH, H2O and CO as test molecules, for which, high quality ab initio results are available. Further, our study of possible incorporation of non-dynamical electron correlation by studying BH and HF at several internuclear distances is discussed.

}, keywords = {Density functional theory, molecular properties, polarizability, Response approach}, isbn = {90-6764-442-0}, issn = {1573-4196}, author = {Pal, Sourav and Sophy, K. B.}, editor = {Maroulis, G and Simos, T} } @article { ISI:000295235200041, title = {Ab initio and periodic DFT investigation of hydrogen storage on light metal-decorated MOF-5}, journal = {International Journal of Hydrogen Energy}, volume = {36}, number = {17}, year = {2011}, month = {AUG}, pages = {10816-10827}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The effect of light metal (M = Li, Be, Mg, and Al) decoration on the stability of metal organic framework MOF-5 and its hydrogen adsorption is investigated by ab initio and periodic density functional theory (DFT) calculations by employing models of the form BDC:M-2:nH(2) and MOF-5:M-2:nH(2), where BDC stands for the benzenedicarboxylate organic linker and MOF-5 represents the primitive unit cell. The suitability of the periodic DFT method employing the GGA-PBE functional is tested against MP2/6-311 + G* and MP2/cc-pVTZ molecular calculations. A correlation between the charge transfer and interaction energies is revealed. The metal-MOF-5 interactions are analyzed using the frontier molecular orbital approach. Difference charge density plots show that H-2 molecules get polarized due to the charge generated on the metal atom adsorbed over the BDC linker, resulting in electrostatic guest-host interactions. Our solid state results show that amongst the four metal atoms, Mg and Be decoration does not stabilize the MOF-5 to any significant extent. Li and Al decoration strengthened the H-2-MOE-5 interactions relative to the pure MOF-5 exhibited by the enhanced binding energies. The hydrogen binding energies for the Li- and Al-decorated MOF-5 were found to be sensible for allowing reversible hydrogen storage at ambient temperatures. A high hydrogen uptake of 4.3 wt.\% and 3.9 wt.\% is also predicted for the Li- and Al-decorated MOF-5, respectively. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

}, keywords = {ab initio calculations, Density functional theory, Hydrogen binding energies, Hydrogen storage, Metal-Pi-Arene interactions}, issn = {0360-3199}, doi = {10.1016/j.ijhydene.2011.05.165}, author = {Dixit, Mudit and Maark, Tuhina Adit and Pal, Sourav} } @article { ISI:000311350000015, title = {First principle investigation on the thermal stability of a golden fullerene: a case study of Au-32}, journal = {Catalysis Today}, volume = {198}, number = {1, SI}, year = {2012}, month = {DEC}, pages = {106-109}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

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.

}, keywords = {Au-32 cluster, Born-Oppenheimer molecular dynamics, Density functional theory, Golden fullerenes, Relativistic effects}, issn = {0920-5861}, doi = {10.1016/j.cattod.2012.04.072}, author = {De, Himadri Sekhar and Krishnamurty, Sailaja and Pal, Sourav} } @article { ISI:000318589100018, title = {Metal or nonmetal cooperation with a phenyl group: route to catalysis? a computational investigation}, journal = {ACS Catalysis}, volume = {3}, number = {5}, year = {2013}, month = {MAY}, pages = {920-927}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Full quantum mechanical calculations demonstrate that cooperativity in the form of the activation of the M-C bond (M: transition metal or boron, C: the ipso carbon of the coordinated phenyl group) can lead to effective catalysis pathways. Calculations show that the presence of an aromatic bidentate ligand attached to a transition metal, or even a main group element, such as boron, can lead to effective catalysts for,a, range of important reactions, such as the dehydrogenation of ammonia borane and formic acid and the activation of the N-H, bond in aromatic amities. Moreover, it is shown that the design of tridentate pincer complexes with the aromatic group at a terminal end can lead to effective M-C cooperativity. As such, the current work introduces a new concept in cooperativity and bond activation chemistry.

}, keywords = {catalysis, Density functional theory, metal-ligand cooperativity, small molecule activation}, issn = {2155-5435}, doi = {10.1021/cs400174u}, author = {Ghatak, Kamalika and Mane, Manoj and Vanka, Kumar} } @article { ISI:000332999800006, title = {Photoelectrochemical splitting of water with nanocrystalline Zn1-xMnxO thin films: first-principle DFT computations supporting the systematic experimental endeavor}, journal = {International Journal of Hydrogen Energy}, volume = {39}, number = {8}, year = {2014}, month = {MAR}, pages = {3637-3648}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Photoelectrochemical splitting of water with nanocrystalline Zn1-xMnxO thin films was investigated. ZnO thin films with 1, 3, 5 and 7\% at. Mn incorporation were synthesized by sol gel method and characterized by X-Ray Diffraction (XRD) analysis, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray Photoelectron spectroscopy (XPS), High Resolution Transmission Electron Microscopy (HR-TEM) and UV-Vis spectroscopy. Mn incorporation coupled with variation in sintering temperature led to significant microstructural changes, which tentatively influenced the magnitude of optical absorption and charge carrier mobility, thereby impacting the performance of such systems towards photoelectrochemical splitting of water. Electronic structure computations based on first principle density functional theory (DFT) revealed electronic states of Mn being responsible for the marginally recorded red shift in bandgap energy. Photoelectrochemical measurements using thin films of 1\% at. Mn:ZnO sintered at 600 degrees C yielded 3 times enhanced photocurrent at zero bias due to improved optical absorption. Plausible explanations for the effect have also been offered. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

}, keywords = {Density functional theory, Hydrogen energy, Mn doped ZnO, Optical properties, Photoelectrochemical water splitting}, issn = {0360-3199}, doi = {10.1016/j.ijhydene.2013.12.150}, author = {Sharma, Vidhika and Dixit, Mudit and Satsangi, Vibha R. and Dass, Sahab and Pal, Sourav and Shrivastav, Rohit} } @article { ISI:000351849100002, title = {Can substituted allenes be highly efficient leaving groups in catalytic processes? a computational investigation}, journal = {Journal of Computational Chemistry}, volume = {36}, number = {11}, year = {2015}, month = {APR}, pages = {795-804}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

There is considerable interest presently in the chemistry of allenes. The current computational investigation looks into the possibility of using allenes and their derivatives as leaving groups. As it is well known, leaving groups are significant in catalytic processes for generating the active site. A full quantum mechanical study using density functional theory shows that allenes and their derivatives can function as excellent leaving groups. Indeed, the calculations show that they can be several orders of magnitude more effective than existing ligands for this purpose. The modification of second generation Grubbs{\textquoteright} catalysts with these ligands suggests that the allene ligand cases that would be most effective are those having electron withdrawing groups, especially those that have the potential for supramolecular interactions between the substituent groups in the free state. (c) 2015 Wiley Periodicals, Inc.

}, keywords = {allenes, carbones, Density functional theory, olefin metathesis, supramolecular interactions}, issn = {0192-8651}, doi = {10.1002/jcc.23855}, author = {Kuriakose, Nishamol and Vanka, Kumar} } @article { ISI:000370057200011, title = {Enhanced electron field emission from NiCo2O4 nanosheet arrays}, journal = {Materials Research Express}, volume = {2}, number = {9}, year = {2015}, month = {SEP}, pages = {095011}, publisher = {IOP PUBLISHING LTD}, address = {TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND}, abstract = {

Electron emission properties of electrodeposited spinel NiCo2O4 nanosheet arrays grown on Ni foam have been studied. The work function of NiCo2O4 was calculated by density functional theory using the plane-wave basis set and used to estimate the field enhancement factor. The NiCo2O4 nanosheet arrays exhibited a low turn-on field of 1.86 V mu m(-1) at 1 mu A cm(-2) and current density of 686 mu A cm(-2) at 3.2 V mu m(-1), with field enhancement factor beta = 1460 and good field emission current stability. The field emission properties of the NiCo2O4 nanosheet arrays showed enhanced performance compared to chemically prepared NiCo2O4 nanosheets. Hence, the nanosheet arrays have great potential as robust high performance vertical structure electron emitters for future flat panel displays and vacuum electronic device applications.

}, keywords = {Density functional theory, field emission, nanosheets, NiCo2O4, spinel}, issn = {2053-1591}, doi = {10.1088/2053-1591/2/9/095011}, author = {Naik, Kusha Kumar and Khare, Ruchita T. and Gelamo, Rogerio V. and More, Mahendra A. and Thapa, Ranjit and Late, Dattatray J. and Rout, Chandra Sekhar} } @article { ISI:000367421500014, title = {Novel 2,6-diformyl-4-methyl phenol based chemosensor for Zn-II ion by ratiometric displacement of Cd-II ion and its application for cell imaging on human melanoma cancer cells}, journal = {Journal of the Indian Chemical Society}, volume = {92}, number = {11}, year = {2015}, month = {NOV}, pages = {1729-1745}, publisher = {SCIENTIFIC PUBL-INDIA}, address = {5-A, NEW PALI RD, PO BOX 91, NEAR HOTEL TAJ HARI MAHAL, JODHPUR, 342 003, INDIA}, abstract = {

A new chelating ligand [4-methyl-2,6-bis-(pyridin-2-yl-hydrazonomethyl)-phenol] (1) was prepared by the condensation of 2-hydrazinylpyridine with 2,6-diformyl-p-cresol. Compound 1 exhibits weak fluorescence due to intramolecular photoinduced electron transfer (PET). The sensor (1) demonstrates Zn2+-specific emission enhancement due to {\textquoteleft}{\textquoteleft}PET off{\textquoteright}{\textquoteright} process through a 1 : 1 binding mode with the metal ion. The fluorescence quantum yield of the chemosensor 1 is only 0.020, and it increases more than 14-fold (0.280) in the presence of one equivalent of the zinc ion. Interestingly, the introduction of other metal ions causes the fluorescence intensity to remain either unchanged or weakened except for Cd2+. Ratiometric displacement of Cd2+ ion from the complex by Zn2+ ion supports the formation of more stable sensor-Zn2+ complex over the sensor-Cd2+ complex. The experimental findings have been correlated with theoretical results using B3LYP functional and 6-31G(d,p), LANL2DZ basis set for Cd2+ (2) and Zn2+ (3) complex, respectively, by Density Functional Theory (DFT) method. Moreover, the ability of probe 1 to sense Zn2+ within human melanoma cancer cells has been explored, and the Zn2+-probing process in living cells was reversible. [Mn-2(PHMP)(2)](ClO4)(2) (4) and [Ni-2(PHMP)(H2O)(5)](NO3)(3) (5) have been also synthesized and characterized crystallographically and spectroscopically to understand the ligating behavior of the ligand PHMP.

}, keywords = {Cd-II ion, Chemosensor, Density functional theory, human melanoma cancer cells, photoinduced electron transfer, Zn-II ion}, issn = {0019-4522}, author = {Mitra, Debarshan and Venkatathari, N. and Sabharwal, S. C. and Godbole, S. V. and Tyagi, A. K. and Das, Sangbrita} } @article { ISI:000354735600005, title = {Theoretical insight of nitric oxide adsorption on neutral and charged Pd-n (n=1-5) clusters}, journal = {International Journal of Quantum Chemistry}, volume = {115}, number = {13}, year = {2015}, month = {JUL}, pages = {837-845}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

Density functional theory (DFT) calculations within the framework of generalized gradient approximation have been used to systematically investigate the adsorption of nitric oxide (NO) molecule on neutral, cationic, and anionic Pd-n (n=1-5) clusters. NO coordinate to one Pd atom of the cluster by the end-on mode, where the tilted end-on structure is more favorable due to the additional electron in the * orbital. On the contrary, in the neutral and cationic Pd-2 system, NO coordinates to the bridge site of cluster preferably by the side-on mode. Charge transfer between Pd clusters and NO molecule and the corresponding weakening of NO bond is an essential factor for the adsorption. The NO stretching frequency follow the order of cationic\>neutral\>anionic. Binding energy of NO on anionic clusters is found to be greater than those of neutral and cationic clusters. (c) 2015 Wiley Periodicals, Inc.

}, keywords = {Density functional theory, electronic property, geometric configuration, NO adsorption, small palladium cluster}, issn = {0020-7608}, doi = {10.1002/qua.24914}, author = {Begum, Pakiza and Gogoi, Pranjal and Mishra, Bhupesh Kumar and Deka, Ramesh Chandra} } @article { ISI:000372756700003, title = {DFT based assay for tailor-made terpyridine ligand-metal complexation properties}, journal = {Molecular Simulations}, volume = {42}, number = {8}, year = {2016}, month = {MAY}, pages = {618-627}, publisher = {TAYLOR \& FRANCIS LTD}, type = {Article}, address = {4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND}, abstract = {

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.

}, keywords = {Binding energy, charge redistribution, Density functional theory, functionalisation, Metal organic complexes, metal-ligand interactions, terpyridine}, issn = {0892-7022}, doi = {10.1080/08927022.2015.1067368}, author = {Joshi, Krati and Krishnamurty, Sailaja and Singh, Iksha and Selvaraj, Kaliaperumal} } @article { ISI:000370900600019, title = {Photoluminescent tetrahedral d(10)-metal Schiff base complexes exhibiting highly ordered mesomorphism}, journal = {Polyhedron}, volume = {105}, year = {2016}, month = {FEB}, pages = {150-158}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A series of four-coordinate d(10)-metal complexes of the type [ML2] {M = Zn, Cd, Hg; L = 4-nitro-2-((octadecylimino)methyl)phenol}, incorporating a new N-alkylated bidentate [N,O]-donor salicylaldimine Schiff base ligand, has been synthesized and characterized by elemental analyses, FT-IR, UV-Vis, H-1 NMR and FAB-mass spectroscopies. The ligand is non-mesomorphic and devoid of any photoluminescence. The zinc(II) and cadmium(II) complexes displayed highly ordered mesophases reminiscent of soft crystals. The phases have been characterized by polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) studies. The complex of mercury(II) decomposed prior to melting. An orthogonal symmetry with a {\textquoteleft}herringbone{\textquoteright} array for the zinc complex and a primitive triclinic symmetry (p(1)) for the cadmium complex, respectively, has been proposed. The complexes exhibited fluorescence at room temperature, both in the solution and in the solid state, with emission maxima in the blue region. Density functional theory (DFT) calculations carried out using the GAUSSIAN 09 program at the B3LYP level revealed a distorted tetrahedral geometry around the metal center in all the complexes. Natural bond orbital (NBO) analysis suggested appreciable charge transfer from the ligand to the metal center in the complexes. (C) 2015 Elsevier Ltd. All rights reserved.

}, keywords = {Density functional theory, Luminescence, Mesophase, Schiff base, X-ray diffraction}, issn = {0277-5387}, doi = {10.1016/j.poly.2015.11.053}, author = {Chakraborty, Sutapa and Purkayastha, Debraj Dhar and Das, Gobinda and Bhattacharjee, Chira R. and Mondal, Paritosh and Prasad, S. Krishna and Rao, D. S. Shankar} } @article {45730, title = {Computational survey of ligand properties on iron(III)-iron(II) redox potential: exploring natural attenuation of nitroaromatic compounds}, journal = {Monatshefte Fur Chemie}, volume = {148}, year = {2017}, month = {APR}, pages = {655-668}, type = {Article}, abstract = {

This study is a computational investigation of the ligand effect on the redox potential of iron redox couple aimed at screening these systems for novel applications. The influence of common and naturally available organic compounds with diverse ligand characteristics (nature of donor site, chelation, pre-organization, degree of back acceptance) on the redox potential of iron(III)-iron(II) redox couple has been theoretically calculated using an appropriate level of density functional theory (DFT). The DFT calculated redox potentials of iron complexes are explored to supplement, corroborate, and predict the experimental behavior of the studied systems towards environmental reduction of nitroaromatic compounds to corresponding anilines. The comparative avidity of iron complexes with cysteine derivatives for the reduction of nitroaromatic compounds has been theoretically explored and based on structure-activity relationship; new iron complexes with a range of reactivity and enhanced ability towards nitroaromatic reduction have been predicted.

}, keywords = {Catechol derivatives, computational chemistry, Density functional theory, Iron complexes, Ligand effect on redox potential, Natural attenuation, Nitroaromatic compounds}, issn = {0026-9247}, doi = {10.1007/s00706-016-1813-8}, author = {Rizvi, Masood Ahmad and Mane, Manoj and Khuroo, Mohammad Akbar and Peerzada, Ghulam Mustafa} } @article {44172, title = {Nitrogen-doped graphene with a three-dimensional architecture assisted by carbon nitride tetrapods as an efficient metal-free electrocatalyst for hydrogen evolution}, journal = {Chemelectrochem}, volume = {4}, year = {2017}, month = {OCT}, pages = {2643-2652}, type = {Article}, abstract = {Current polymer membrane-based electrolyzers use Pt as a cathode catalyst for efficient reduction of water. The high cost of Pt-based catalysts forces researchers to develop alternative electrocatalysts. Here, a simple strategy has been proposed to synthesize a metal-free electrocatalyst for the hydrogen evolution reaction (HER) by high-temperature annealing of graphene oxide-coated melamine foam. The prepared catalyst possesses both structural and functional advantages with its three-dimensional (3D) interconnected arms of carbon nitride (CNx) backbone wrapped with nitrogen-doped graphene (N-RGO) sheets (CNx@N-RGO). CNx@N-RGO faces only a 193 mV overpotential to achieve a current density of 10mAcm(-2), which is far superior to the previously reported Pt-free systems. Along with the high exchange current density 34.7 x 10(-6)A cm(-2) and low Tafel slope of 54 mV dec(-1), CNx@N-RGO follows a Volmer-Heyrovsky mechanism for the HER. DFT calculations show that the synergy between CNx and N-RGO facilitates good electrical coupling between the two moieties and provides optimal binding to H+ ions on the catalyst that, in turn, results in efficient reduction of hydrogen ions.}, keywords = {carbon nitride, Density functional theory, electrocatalyst, hydrogen evolution reaction, nitrogen doped graphene}, issn = {2196-0216}, doi = {10.1002/celc.201700479}, author = {Gangadharan, Pranav K. and Unni, SreeKuttan M. and Kumar, Nandha and Ghosh, Prasenjit and Kurungot, Sreekumar} } @article {44624, title = {B(C6F5)(3): catalyst or initiator? insights from computational studies into surrogate silicon chemistry}, journal = {ACS Catalysis}, volume = {8}, year = {2018}, month = {JUL}, pages = {6163-6176}, type = {Article}, abstract = {

One of the most promising recent developments in catalysis has been the use of the metal-free Lewis acid B(C6F5)(3) as a catalyst for a range of different chemical transformations. Perhaps the most impressive achievement in this regard is the recently accomplished in situ generation of SiH4 from surrogates (Simonneau and Oestreich, Nat. Chem., 2015,7, 816). However, what the current computational work, with density functional theory, reveals is that this process, in addition to being catalyzed by B(C6F5)(3), is also significantly dominated by a series of autocatalytic reactions. The results are further corroborated by the use of the energetic span model, which shows that the turnover frequency is higher for the newly proposed autocatalytic pathway in comparison to the conventional B(C6F5)(3)-catalyzed pathway. The current work therefore provides interesting new insights into surrogate silicon chemistry. But, more importantly, the current studies indicate that B(C6F5)(3) is likely to function more as an initiator rather than a pure catalyst in many metal-free transformations that have been reported to date.

}, keywords = {autocatalysis, Density functional theory, ion-pair, Lewis acid catalysis, reaction mechanism, surrogate silicone chemistry, tris(pentafluorophenyl)borane}, issn = {2155-5435}, doi = {10.1021/acscatal.7b04489}, author = {Banerjee, Subhrashis and Vanka, Kumar} } @article {44560, title = {Revealing optoelectronic and transport properties of potential perovskites Cs2PdX6 (X = Cl, Br): A probe from density functional theory (DFT)}, journal = {Solar Energy}, volume = {162}, year = {2018}, month = {MAR }, pages = {336-343}, abstract = {

Metal-halide perovskites are rapidly emerging crystalline materials that are reasonably preferred as leading aspirant for applications in optoelectronic and thermoelectric devices. In this paper, we have thoroughly reviewed and performed calculations to reveal optoelectronic and transport properties for a potential newcomer, Cs2PdX6 (X = Cl, Br) termed as Cesium Palladium Halides (CPH). Outcome of present computations are compared with available results and a reasonable agreement is recorded. Energy band gap computations performed reveal indirect band gap of 2.29 eV for Cs2PdC16, which substantially reduces to 1.22 eV when {\textquoteleft}Cl{\textquoteright} is replaced by {\textquoteleft}Br{\textquoteright}. Optical absorption spectra investigations performed here, in the energy range from 3 to 5 eV confirms effective utilization of these compounds in solar cells and other optoelectronic applications. In addition, the transport properties computations performed using semi-classical Boltzmann theory, shows constant pattern of thereto power near ambient temperature range (200-500 K), which admits possible utilization of these compounds as low temperature thermoelectric materials. Performed ZT calculations demonstrates reasonably good thermoelectric performance for both materials, as there exist minor variation (0.1) in the values over wide temperature ranges i.e. from 100 to 800 K. Further, detailed analysis of transport properties predicts p-type semiconducting nature of the present series of materials.

}, keywords = {Ab-initio studies, Density functional theory, Optical properties, Transport properties}, issn = {0038-092X}, doi = {10.1016/j.solener.2018.01.059}, author = {Bhamu, K. C. and Soni, Amit and Sahariya, Jagrati} } @article {44450, title = {Tuning of terahertz resonances of pyridyl benzamide derivatives by electronegative atom substitution}, journal = {Journal of Infrared, Millimeter, and Terahertz Waves}, volume = {39}, year = {2018}, month = {JUL}, pages = {636{\textendash}650}, type = {Journal Article}, abstract = {

N-(pyridin-2-yl) benzamide (Ph2AP)-based organic molecules with prominent terahertz (THz) signatures (less than 5 THz) have been synthesized. The THz resonances are tuned by substituting the most electronegative atom, fluorine, at ortho (2F-Ph2AP), meta (3F-Ph2AP), and para (4F-Ph2AP) positions in a Ph2AP molecule. Substitution of fluorine helps in varying the charge distribution of the atoms forming hydrogen bond and hence strength of the hydrogen bond is varied which helps in tuning the THz resonances. The tuning of lower THz resonances of 2F-Ph2AP, 3F-Ph2AP, and 4F-Ph2AP has been explained in terms of compliance constant (relaxed force constant). Four-molecule cluster simulations have been carried out using Gaussian09 software to calculate the compliance constant of the hydrogen bonds. Crystal structure simulations of the above molecules using CRYSTAL14 software have been carried out to understand the origin of THz resonances. It has been observed that THz resonances are shifted to higher frequencies with stronger hydrogen bonds. The study shows that 3F-Ph2AP and 4F-Ph2AP have higher hydrogen bond strength and hence the THz resonances originating due to stretching of intermolecular hydrogen bonds have been shifted to higher frequencies compared to 2F-Ph2AP. The methodology presented here will help in designing novel organic molecules by substituting various electronegative atoms in order to achieve prominent THz resonances.

}, keywords = {Compliance constant, Density functional theory, Ph2AP molecule, Terahertz spectroscopy}, issn = {18666892}, doi = {10.1007/s10762-018-0500-8}, author = {Dash, Jyotirmayee}, editor = {Ray, Shaumik} } @article {45501, title = {Facile production of mesoporous WO3-rGO hybrids for high-performance supercapacitor electrodes: an experimental and computational study}, journal = {ACS Sustainable Chemistry \& Engineering}, volume = {7}, year = {2019}, month = {JAN}, pages = {2350-2359}, type = {Article}, abstract = {

This work explored a promising supercapacitor electrode material (WO3-rGO hybrids) synthesized via a simplistic one-pot hydrothermal synthesis route. Various analytical studies (X-ray diffraction study, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller analysis) were employed in furtherance to explore the structural, morphological, compositional, and surface areal properties of the prepared materials. The enhancement in electrochemical supercapacitive properties were evaluated from pure hexagonal phase WO3 to the various hybrids, depending on the concentration of GO introduced into it, using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The WG-80 composite revealed the high rise in capacitance value of 801.6 F/g overcoming the individual capacitance of rGO (71.11 F/g) and WO3 (94.22 F/g) at a current density of 4 A/g with good cycling stability (75.7\%) over 5000 cycles. We have presented quantum capacitance from ab initio calculations and provided theoretical explanation from the orbital interactions.

}, keywords = {Density functional theory, Hydrothermal method, supercapacitor, WO3-rGO hybrids}, issn = {2168-0485}, doi = {10.1021/acssuschemeng.8b05132}, author = {Samal, Rutuparna and Chakraborty, Brahmananda and Saxena, Manav and Late, Dattatray J. and Rout, Chandra Sekhar} } @article {44433, title = {VSe2-reduced graphene oxide as efficient cathode material for field emission}, journal = {Journal of Physics and Chemistry of Solids }, volume = {128}, year = {2019}, month = {MAY}, pages = {384-390}, type = {Journal Article}, abstract = {

Field emission properties of pristine VSe2 and its hybrid with reduced graphene oxide (RGO) have been investigated in detail. Promising field emission performance were noted with lower values of turn-on and threshold fields of \~{}1.3 V μm-1 and 2.12 V μm-1 respectively for the VSe2/RGO hybrid which is much more superior than that of pristine VSe2 emitter and other 2D materials. Density Functional Theory (DFT) simulations have also been performed to qualitatively support our experimental observations through demonstration of Density of States and computation of work function for pristine VSe2 and hybrid VSe2/RGO. The lowering of work function and appearance of additional states near Fermi level from carbon p orbital of RGO is responsible for superior field emission characteristics in hybrid VSe2/RGO compared to pristine VSe2 which supports our experimental observations. Our experimental data and theoretical insight from electronic structure simulations strongly infer that the synthesized hybrid VSe2/RGO has the potential to be tailored as efficient and high performance cathode material in field emission based devices.

}, keywords = {cathode material, Chalcogenide, Density functional theory, field emission, Vanadium diselenide, Work function}, issn = {223697}, doi = {10.1016/j.jpcs.2018.02.020}, author = {Ratha, S.}, editor = {Bankar, P.} } @article {46926, title = {Investigating effect of strain on electronic and optical properties of lead free double perovskite Cs2AgInCl6 solar cell compound: A first principle calculation}, journal = {Journal of Alloys and Compounds}, volume = {817}, year = {2020}, month = {MAR}, pages = {152758}, type = {Article}, abstract = {

Despite serious problems associated with toxicity of lead, lead halide perovskite based solar cells have resulted with remarkable efficiency and hence gained much interest. To overcome this aspect, numerous solutions are attempted by researchers which include the development of new environmental friendly lead free double perovskite (DP) photovoltaic materials. Enlightening on the same line, we report first principle calculations on electronic and optical properties of Cs2AgInCl6 solar photovoltaic materials. Present opto-electronic computations for lead free DP compound, have been performed using the full potential linearized augmented plane wave method. In present investigations, we have adopted exchange and correlation potentials prescribed by Perdew et al. and the most accurate Tran-Blaha modified Becke-Johnson. Both exchange and correlation potential computations are performed with and without spin orbit coupling. Results obtained for electronic and optical properties are validated by systematic comparison with available experimental data. Reasonable reconciliation between investigated results and the available experimental data, endorse accuracy of present computations. To identify the effect of strain on energy gap and hence on the optical properties of Cs2AgInCl6 compound, computations of electronic and optical properties have also been performed under the different values of strain application. (C) 2019 Elsevier B.V. All rights reserved.

}, keywords = {Density functional theory, Electronic Structure, Optical properties, solar cells}, issn = {0925-8388}, doi = {10.1016/j.jallcom.2019.152758}, author = {Soni, Amit and Bhamu, K. C. and Sahariya, Jagrati} } @article {46892, title = {Unravelling the distinct surface interactions of modified graphene nanostructures with methylene blue dye through experimental and computational approaches}, journal = {Journal of Hazardous Materials}, volume = {388}, year = {2020}, month = {APR}, pages = {121755}, type = {Article}, abstract = {

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.

}, keywords = {Density functional theory, In-situ UV-vis spectroscopy, Interactions, Methylene blue, Modified Graphene Nanostructures}, issn = {0304-3894}, doi = {10.1016/j.jhazmat.2019.121755}, author = {Manappadan, Zinoy and Kumar, Shubham and Joshi, Krati and Govindaraja, Thillai and Krishnamurty, Sailaja and Selvaraj, Kaliaperumal} } @article {47602, title = {Insights into chemical reactions at the beginning of the universe: from HeH+ to H-3 (+)}, journal = {Frontiers in Chemistry}, volume = {9}, year = {2021}, month = {JUN }, pages = {679750}, type = {Article}, abstract = {At the dawn of the Universe, the ions of the light elements produced in the Big Bang nucleosynthesis recombined with each other. In our present study, we have tried to mimic the conditions in the early Universe to show how the recombination process would have led to the formation of the first ever formed diatomic species of the Universe: HeH+, as well as the subsequent processes that would have led to the formation of the simplest triatomic species: H-3 (+). We have also studied some special cases: higher positive charge with fewer number of hydrogen atoms in a dense atmosphere, and the formation of unusual and interesting linear, dicationic He chains beginning from light elements He and H in a positively charged atmosphere. For all the simulations, the ab initio nanoreactor (AINR) dynamics method has been employed.}, keywords = {ab initio molecular dynamics, ab initio nanoreactor, Density functional theory, origin of molecules in the universe, the earliest lewis acid}, issn = {2296-2646}, doi = {10.3389/fchem.2021.679750}, author = {Dash, Soumya Ranjan and Das, Tamal and Vanka, Kumar} } @article {47380, title = {One-dimensional multichannel g-C3N4.7 nanostructure realizing an efficient photocatalytic hydrogen evolution reaction and its theoretical investigations}, journal = {ACS Applied Energy Materials}, volume = {4}, year = {2021}, month = {APR }, pages = {3118-3129}, type = {Article}, abstract = {

The emerging metal-free carbon nitride (C3N4) offers prominent possibilities for realizing the highly effective hydrogen evolution reaction (HER). However, its poor surface conductivity and insufficient catalytic sites hinder the HER performance. Herein, a one-dimensional vermicular rope-like graphitic carbon nitride nanostructure is demonstrated that consists of multichannel tubular pores and high nitrogen content, which is fabricated through a cost-effective approach having the final stoichiometry g-C3N4.7 for HER application. The present g-C3N4.7 is unique owing to the presence of abundant channels for the diffusion process, modulated surface chemistry with rich- electroactive sites from N-electron lone pairs, greatly reduced recombination rate of photoexcited exciton pairs, and a high donor concentration (4.26 x 10(17) cm(3)). The catalyst offers a visible-light-driven photocatalytic H-2 evolution rate as high as 4910 mu mol h(-1)g(-1) with an apparent quantum yield of 14.07\% at band gap absorption (2.59 eV, 479 nm) under 7.68 mW cm(-2) illumination. The number of hydrogen gas molecules produced is 1.307 x 10(15) s(-1) cm(-2), which remained constant for a minimum of 18 h of repeated cycling in the HER without any degradation of the catalyst. In density functional theory calculations, a significant change in the band offset is observed due to N doping into the system in favor of electron catalysis. The theoretical band gap of a monolayer of g-C3N4.7 was enormously reduced because of the presence of additional densities of states from the doped N atom inside the band gap. These impurity or donor bands are formed inside the band gap region, which ultimately enhance the hydrogen ion reduction reaction enormously.

}, keywords = {carbon nitride, Density functional theory, hydrogen evolution reaction, nitrogen-rich, Photocatalyst}, issn = {2574-0962}, doi = {10.1021/acsaem.0c02858}, author = {Antil, Bindu and Kumar, Lakshya and Ranjan, Ravi and Shenoy, Sulakshana and Tarafder, Kartick and Gopinath, Chinnakonda S. and Deka, Sasanka} } @article {47759, title = {Facile fabrication of nano silver phosphate on B-doped g-C3N4: an excellent p-n heterojunction photocatalyst towards water oxidation and Cr (VI) reduction}, journal = {Journal of Alloys and Compounds}, volume = {898}, year = {2022}, month = {MAR}, pages = {162853}, type = {Article}, abstract = {A 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.}, keywords = {Cr (VI) reduction, Density functional theory, Interfacial zone, p-n heterojunction, Photocatalyst, Water oxidation}, issn = {0925-8388}, doi = {10.1016/j.jallcom.2021.162853}, author = {Sahoo, Mitarani and Babu, Pradeepta and Singh, Chandrodai Pratap and Krishnamurty, Sailaja and Parida, Kulamani} } @article {48268, title = {Chemically modified graphene sheets as potential sensors for organophosphate compounds(pesticide): A DFT study}, journal = {Applied Surface Science}, volume = {619}, year = {2023}, month = {MAY}, pages = {156745}, type = {Article}, abstract = {

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.

}, keywords = {Adsorption, BN doped graphene surfaces, Charge density difference, Density functional theory, Organophosphate pesticides}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2023.156745}, author = {Shivankar, Bhavana R. and Singh, Chandrodai Pratap and Krishnamurty, Sailaja} } @article {48803, title = {Mitigating dendrite formation on a Zn electrode in aqueous zinc chloride by the competitive surface chemistry of an imidazole additive}, journal = {ACS Applied Materials and Interfaces}, volume = {15}, year = {2023}, month = {MAY}, pages = {23093-23103}, type = {Article}, abstract = {

Electrochemical energy storage systems are critical in several ways for a smooth transition from nonrenewable to renewable energy sources. Zn-based batteries are one of the promising alternatives to the existing state-of-the-art Li-ion battery technology, since Li-ion batteries pose significant drawbacks in terms of safety and cost-effectiveness. Zn (with a reduction potential of -0.76 V vs SHE) has a significantly higher theoretical volumetric capacity (5851 mAh/cm3) than Li (2061 mAh/cm3), and it is certainly far less expensive, safer, and more earth-abundant. The formation of dendrites, hydrogen evolution, and the formation of a ZnO passivation layer on the Zn anode are the primary challenges in the development and deployment of rechargeable zinc batteries. In this work, we examine the role of imidazole as an electrolyte additive in 2 M ZnCl2 to prevent dendrite formation during zinc electrodeposition via experimental (kinetics and imaging) and theoretical density functional theory (DFT) studies. To characterize the efficacy and to identify the appropriate concentration of imidazole, linear sweep voltammetry (LSV) and chronoamperometry (CA) are performed with in situ monitoring of the electrodeposited zinc. The addition of 0.025 wt \% imidazole to 2 M ZnCl2 increases the cycle life of Zn-symmetric cells cycled at 1 mA/cm2 for 60 min of plating and stripping dramatically from 90 to 240 h. A higher value of the nucleation overpotential is noted in the presence of imidazole, which suggests that imidazole is adsorbed at a competitively faster rate on the surface of zinc, thereby suppressing the zinc electrodeposition kinetics and the formation. X-ray tomography reveals that a short circuit caused by dendrite formation is the main plausible failure mechanism of Zn symmetric cells. It is observed that the electrodeposition of zinc is more homogeneous in the presence of imidazole, and its presence in the electrolyte also inhibits the production of a passivating coating (ZnO) on the Zn surface, thereby preventing corrosion. DFT calculations conform well with the stated experimental observations.

}, keywords = {dendrite, Density functional theory, exchange current density, Imidazole, X-ray computed tomography, zinc metal electrodeposition}, issn = {1944-8244}, doi = {10.1021/acsami.3c01310}, author = {Rana, Ashutosh and Thakare, Anup and Kumar, Nikhil and Mukherjee, Buddhadev and Torris, Arun and Das, Bidisa and Ogale, Satishchandra and Banerjee, Abhik} } @article {49362, title = {Indazole-5-amine (AIA) as competing corrosion coating to Benzotriazole (BTAH) at the interface of Cu: A DFT and BOMD case study}, journal = {Computational and Theoretical Chemistry}, volume = {1239}, year = {2024}, month = {SEP}, pages = {114762}, type = {Article}, abstract = {

This study compares three organic compounds-benzotriazole (BTAH), imidazole (IM), and indazole-5-amine (AIA)-as corrosion inhibitors for copper substrates. Using Density Functional Theory (DFT) and Born-Oppenheimer Molecular Dynamics (BOMD) calculations, it identifies AIA as a promising and cost-effective alternative to the toxic BTAH. The adsorption strength on Cu(1 0 0) surfaces is ranked AIA\>BTAH\>IM for both neutral and deprotonated forms. These findings are supported by electronic parameter studies, including Bader charge analysis, density of states (DOS), charge density differences (CDD), and frontier molecular orbital analysis. AIA shows the best adsorption in a parallel orientation at the top site. Packing studies reveal that hydrogen bonding stabilizes the interaction energies within self-assembled AIA aggregates. Organometallic complexation studies reveal that deprotonated BTAH exhibits higher interaction energy with a single Cu atom compared to AIA when bonded through the carbon end, consistent with the findings from BOMD studies. However, on periodic Cu surfaces, AIA outperforms BTAH molecules as seen from adsorption energies. This investigation highlights AIA{\textquoteright}s potential as a superior and more economical corrosion inhibitor for copper.

}, keywords = {Adsorption, Born-Oppenheimer molecular dynamics, Corrosion inhibition, Density functional theory, Indazole derivatives}, issn = {2210-271X}, doi = {10.1016/j.comptc.2024.114762}, author = {Samal, Pragnya Paramita and Singh, Chandrodai Pratap and Tiwari, Shivani and Shah, Vaishali and Krishnamurty, Sailaja} } @article {49058, title = {Quasi-molecular hydrogen storage capacity of graphene quantum dots: A dispersion corrected DFT study}, journal = {Journal of Energy Storage}, volume = {84}, year = {2024}, month = {APR }, type = {Article}, abstract = {

Efficient storage of hydrogen, green fuel with the highest energy density, remains a pressing challenge. Among the several materials investigated for their potential hydrogen storage, 2D materials, like graphene, have advantages such as mechanical strength and large surface area but fail to store hydrogen reversibly. In this context, the present computational experiment demonstrates the potential of Graphene Quantum Dots (GQDs) with 24, 40 and 42 carbon atoms for their hydrogen storage capacity in quasi-molecular mode. Factors such as edge terminations, heteroatom doping, and anchoring of metal atoms are evaluated as a function of their storage capacity. The study clearly demonstrates an enhanced storage capacity of quantum dots, particularly, when a single Ti adatom is anchored on a 24 carbon atom GQD with a storage weight \% of 2.24 \% w/w. The storage weight \% is further noted to increase as a function of the number of Ti atoms anchored on the GQD with the highest hydrogen storage weight \% of 6.1 \% w/w. Importantly, the adsorption of hydrogen molecule on the Ti atom is through a quasi-molecular mode and is driven by Kubas interaction. This type of interactions makes GQDs as viable storage materials at room temperature. Secondly, the work demonstrates that GQDs offer higher storage capacities of hydrogen molecules as compared to their 2D counterparts viz., graphene sheets, making them attractive candidates to be explored experimentally.

}, keywords = {Density functional theory, graphene quantum dots, Hydrogen storage, Kubas interaction, Quasi -molecular adsorption, Ti adatom}, issn = {2352-152X}, doi = {10.1016/j.est.2024.110833}, author = {Khadilkar, Pranav and Samudre, Nikhil S. and Krishnamurty, Sailaja} } @article {49044, title = {Role of aromatic alcohol additives on asymmetric organocatalysis reactions: insights from theory}, journal = {Chemistry-an asian jounrnal}, volume = {19}, year = {2024}, month = {FEB }, type = {Article}, abstract = {

The presence of an aromatic additive has been seen to enhance, often significantly, the enantioselectivity and yield in asymmetric organocatalysis. Considering their success across a dizzying range of organocatalysts and organic transformations, it would seem unlikely that a common principle exists for their functioning. However, the current investigations with DFT suggest a general principle: the phenolic additive sandwiches itself, through hydrogen bonding and pi \& sdot;\& sdot;\& sdot;pi stacking, between the organocatalyst coordinated electrophile and nucleophile. This is seen for a wide range of experimentally reported systems. That such complex formation leads to enhanced stereoselectivity is then demonstrated for two cases: the cinchona alkaloid complex (BzCPD), catalysing thiocyanation (2-naphthol additive employed), as well as for L-pipecolicacid catalysing the asymmetric nitroaldol reaction with a range of nitro-substituted phenol additives. These findings, indicating that dual catalysis takes place when phenolic additives are employed, are likely to have a significant impact on the field of asymmetric organocatalysis. The current DFT based study, on a wide range of organocatalysis systems, reveals a general principle by which phenolic additives influence asymmetric organocatalysis reactions. It is shown that the phenolic additive forms a sandwich complex, through hydrogen bonding and pi \& sdot;\& sdot;\& sdot;pi stacking interactions, with the organocatalyst coordinated electrophile and nucleophile, and enhances the enantioselectivity of the system as a result. image

}, keywords = {Additive, Asymmetric Organocatalysis, Cinchona Alkaloid, Density functional theory, Enantioselective Thiocyanation}, issn = {1861-4728}, doi = {10.1002/asia.202300997}, author = {Banerjee, Subhrashis and Vanka, Kumar} } @article {49350, title = {Ultra-small Au nanoclusters with tailored photoluminescence properties using modified thiol ligands: a computational and experimental demonstration}, journal = {Particle \& Particle Systems Characterization}, volume = {41}, year = {2024}, month = {OCT}, type = {Article}, abstract = {

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 {\textquoteleft},N {\textquoteleft}{\textquoteright}-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 {\textquoteleft},N {\textquoteleft}{\textquoteright}-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 {\textquoteleft}{\textquoteleft}molecular{\textquoteright}{\textquoteright} 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 {\textquoteleft}-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

}, keywords = {Density functional theory, photoluminescent Au nanoclusters, surface plasmon resonance, thiol ligand}, issn = {0934-0866}, doi = {10.1002/ppsc.202400011}, author = {Chahande, Anurag M. and Maibam, Ashakiran and Krishnamurty, Sailaja and Devi, R. Nandini} } @article {49052, title = {Unveiling electronic structure and magnetic properties of AFe2O4 (A = Co, Ni, Zn, and Mg): Synergizing experimentation with DFT investigation}, journal = {Solid State Communications}, volume = {382}, year = {2024}, month = {APR }, pages = {115459}, type = {Article}, abstract = {

This study presents the synthesis of nano-crystalline spinel ferrites AFe2O4 (A = Co2+, Ni+2, Zn+2, and Mg+2), through the sol-gel method, yielding crystallite sizes ranging from 12 to 28 nm. The variation in IR and Raman spectra due to M-O-M bonding supports the variation in lattice parameters. The magnetization measurements revealed that CoFe2O4 has a high saturation magnetization of -55 emu/g and coercivity of -1350 Oe, while ZnFe2O4 exhibited saturation magnetization value of -8 emu/g and coercivity of -16 Oe. In addition, the electronic structure calculated using DFT, which corroborated the antiparallel alignment of Fe ions in the tetrahedral and octahedral sites, validating the measured magnetic moments. Notably, the CoFe2O4 ferrite exhibited a higher squareness ratio than other ferrites, signifying its suitability as a magnetic material for audiovideo recording.

}, keywords = {Density functional theory, Ferrites, Magnetic materials, X-ray diffraction}, issn = {0038-1098}, doi = {10.1016/j.ssc.2024.115459}, author = {Dhaka, Saroj and Shukla, Aarti and Garima and Poonia, Kavita and Kumar, Sudesh} } @article {49897, title = {C=C insertion over N=C=O of allyl isocyanate into the Ge-Si bond of a germylene}, journal = {European Journal of Inorganic Chemistry}, volume = {28}, year = {2025}, month = {SEP}, type = {Article}, abstract = {

Two isocyanates are reacted with the germylene, PhC(NtBu)(2)Ge-Si(SiMe3)(3) (1). Phenyl isocyanate undergoes catalytic cyclotrimerization with 1 leading to 1,3,5-triphenyl isocyanurate (2), while allyl isocyanate undergoes both cyclotrimerization and the C=C bond insertion between the Ge-Si bond. The constitution of 3 is determined by single-crystal X-ray studies. The contrasting reactivity pattern is explained by comprehensive density functional theory studies.

}, keywords = {Cyclotrimerization, Density functional theory, Germylene, Insertion, isocyanates}, issn = {1434-1948}, doi = {10.1002/ejic.202500305}, author = {Ajithkumar, V. S. and Khilari, Nripen and Ghanwat, Pratiksha B. and Koley, Debasis and Sen, Sakya S.} } @article {49935, title = {Electronic, magnetic, and mechanical properties of co-doped GaSb: A promising diluted magnetic semiconductor}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {632}, year = {2025}, month = {NOV }, pages = {173499}, type = {Article}, abstract = {

{Understanding the interplay between magnetism and the electronic structure is crucial for the development of novel spintronic materials. This study employs density functional theory (DFT) calculations to investigate these properties in cubic Gallium Antimonide (GaSb) doped with Cobalt (Co) (Ga1-xCoxSb

}, keywords = {Density functional theory, Dilute magnetic semiconductors, Electronic properties, GaSb, mechanical properties, Spintronic materials}, issn = {0304-8853}, doi = {10.1016/j.jmmm.2025.173499}, author = {Samant, Ramnath and Saraf, Deepashri and Adhikari, Rajendra P. and Shilkar, Omkar and Raikar, Sakshit and Silveira, Allan and Sawant, Manthan and Sappati, Subrahmanyam and Joshi, Niharika and Desai, Ashish M.} } @article {49494, title = {Evaluating the catalytic potential of Lithium-decorated graphene quantum dots for small molecule activation}, journal = {Chemical Physics}, volume = {595}, year = {2025}, month = {JUL}, pages = {112682}, type = {Article}, abstract = {

The search for effective catalysts in small molecule activation has intensified as industries seek efficient and costeffective solutions. Lithium (Li), known for its unique electronic properties, is of significant interest as a catalyst. However, its specific catalytic potential when anchored on graphene quantum dots (GQDs) has not been fully explored. This study investigates the catalytic potential of lithium (Li) adatoms on GQDs with various edge conformations (zigzag and armchair) and sizes (24 and 42 atoms). Using density functional theory (DFT), we examine the interactions of Li-decorated GQDs with small molecules such as H2, N2, CO, O2, and CO2. Our findings reveal that Li-GQD complexes exhibit optimal catalytic activity for all these molecules, based on binding energy, charge distribution, and bond length changes. The smallest GQD, coronene (24 carbon atoms), shows the most promising catalytic activity, providing experimental leads for synthesizing and testing efficient Li-anchored catalysts.

}, keywords = {Catalytic activity, Density functional theory, graphene quantum dots, Lithium adatom, small molecule activation}, issn = {0301-0104}, doi = {10.1016/j.chemphys.2025.112682}, author = {Samudre, Nikhil S. and Tiwari, Rukminesh} } @article {49955, title = {Synthesis, characterization, computational and biological evaluation of pyrazole hydrazones as promising anti-inflammatory agents}, journal = {Scientific Reports}, volume = {15}, year = {2025}, month = {NOV }, pages = {42206}, type = {Article}, abstract = {

In this study, two pyrazole-based hydrazone derivatives, 5-methyl-1-phenyl-4-(1-(2-phenylhydrazineylidene)ethyl)-1H-pyrazole (PMPH) and 1-(4-fluorophenyl)-5-methyl-4-(1-(2-phenylhydrazineylidene)ethyl)-1H-pyr azole (4F-PMPH), were synthesized and the structures of the compounds were elucidated through FT-IR, 1H and 13C NMR, and mass spectral methods. The anti-inflammatory potential was evaluated using the bovine serum albumin denaturation assay, with PMPH and 4F-PMPH showing maximum inhibition at 0.5 mg/mL, respectively, suggesting that fluorine substitution enhances bioactivity. Molecular docking studies against COX-II (PDB: 3LN1) revealed favorable binding energies of - 7.21 kcal/mol (PMPH) and - 8.03 kcal/mol (4F-PMPH). Molecular dynamics simulation of the best docked compound 4F-PMPH with COX-II (PDB: 3LN1) revealed a stable complex over a 100 ns simulation, supporting its potential as a promising inhibitor. In silico ADME analyses revealed pharmacokinetic behavior and drug-likeness. A comparative Density functional theory-based spectroscopic and electronic investigation was conducted using the B3LYP/6-31G(d,p) level of theory. Vibrational frequency analysis showed strong correlation between theoretical and experimental IR spectra. Frontier molecular orbital analysis, molecular electrostatic surface potential maps, Mulliken charges, electronic and global reactivity parameters were also studied. Besides, reduced density gradient, non-covalent interaction, electron localization function, and localized orbital locator maps were analyzed for both the compounds.

}, keywords = {Anti-inflammatory, Density functional theory, Drug design, Hydrazone, Pyrazole}, issn = {2045-2322}, doi = {10.1038/s41598-025-26088-9}, author = {Deshmukh, Hemant S. and Adole, Vishnu A. and Frit, A. Alfind Paul and Mali, Suraj N. and Yasin, Haya Khader Ahmad and Patil, Bhausaheb N. and Janani, S. and Jagdale, Bapu S.} } @article {50044, title = {Effect of sulfonation density on acid strength in ion exchange resins: Insights from solid-state NMR and density functional theory}, journal = {Molecular Catalysis}, volume = {593}, year = {2026}, month = {MAR }, pages = {115794}, type = {Article}, abstract = {

Ion-exchange (IE) resins are widely used as solid acid catalysts; however, their surface acidity remains poorly characterized because their limited thermal stability precludes conventional NH3-based acidity measurements. Moreover, acid-site accessibility in IE resins is strongly governed by solvent- or reactant-induced swelling. Here, we investigate the surface acidity of commercial Amberlyst and Indion IE resins using \& sup3;\& sup1;P MAS NMR (Magic Angle Spinning Nuclear Magnetic Resonance), employing TMPO as a molecular probe dispersed on the resin with moderately swelling dichloromethane, thereby capturing the swollen-state acidity relevant for predicting catalytic activity. The deconvolution of the P-31 MAS NMR spectra reveals three distinct acid-strength zones arising from inhomogeneous sulfonation of the polymer matrix. The overall acidity, quantified by the area-weighted average P-31 chemical shift (delta), increases monotonically with sulfonation density. Notably, only resins containing acid sites stronger than similar to 80 ppm exhibited measurable catalytic activity in alpha-pinene isomerization, establishing a direct correlation between acidity and activity. Density functional theory (DFT) calculations on representative resin models, supported by electron-density analyses, attribute the enhancement of acid strength at higher sulfonation densities to cooperative hydrogen-bonding networks among neighboring sulfonic acid groups. Together, these findings establish P-31 MAS NMR-derived surface acidity as a catalytically relevant descriptor for the rational selection of IE resins in liquid phase acid-catalyzed chemistries.

}, keywords = {Acid strength, Density functional theory, heterogeneous catalysis, Ion-exchange resins, Solid acids, Solid-state NMR}, issn = {2468-8231}, doi = {10.1016/j.mcat.2026.115794}, author = {Tumulu, Goutam Narayan and Datar, Sarvesh and Shelke, Ankita and Swain, Gitanjali and Ajithkumar, T. G. and Thirumalaiswamy, Raja and Mohan, Ojus and Mahajani, Sanjay M.} } @article {49958, title = {Structural characterisation, anticancer properties, and BSA binding of 2,6-dipyrazinylpyridines: Insights from experiment and theory}, journal = {Journal of Molecular Structure}, volume = {1351}, year = {2026}, month = {FEB }, pages = {144225}, type = {Article}, abstract = {

The phenyl-(2,6-di-2-pyrazinyl)pyridine derivatives (L1, L2) were synthesized using a one-pot Krohnke-type method, starting from 2-acetylpyrazine and substituted benzaldehydes. Their structures were characterized using a combination of spectroscopic (NMR, HRMS) and single-crystal X-ray diffraction techniques, complemented by density functional theory (DFT). Single-crystal X-ray diffraction reveals that L1 crystallizes in the C2/c space group (T = 296 K) with its supramolecular assembly being stabilized by C-H \& ctdot;N and pi-pi stacking interactions, whereas L2 facilitates C-H \& ctdot;N, N-H \& ctdot;pi bifurcated, and pi-pi* interactions. The bio-interaction properties of L1 were studied using fluorescence spectroscopy with bovine serum albumin (BSA) as a model protein. Fluorescence studies demonstrated L1 induces static quenching of BSA, with a binding constant of 5.15 x 104 mol \& sdot;dm-3. Synchronous and three-dimensional fluorescence spectra further demonstrated that L1 brings forth significant conformational changes in BSA. The compounds were evaluated for cytotoxicity against the HCT-116 human colorectal cancer cell line.

}, keywords = {2, 6-dipyrazinylpyridines, Bovine serum albumin interaction, Cytotoxicity (HCT-116 cells), Density functional theory, Halogenated derivatives, Single-crystal X-ray diffraction}, issn = {0022-2860}, doi = {10.1016/j.molstruc.2025.144225}, author = {Enumula, Sreenivasulu and Shaikh, Javed and Shaikh, Amin and Sheikh, Kounsar N. and Tambe, Pranav and Lande, Dipali N. and Gejji, Shridhar P. and Shaligram, Parth and Gonnade, Rajesh and Bhadbhade, Mohan and Ahmed, Khursheed} }