Showing papers by "Santanab Giri published in 2011"
TL;DR: This research attacked the mode confusion problem by developing a modeling framework to describe the “spin Dependent Generalizations” of the response of the nervous system to quantum fluctuations.
Abstract: 6.1. Molecular Vibrations PR58 6.2. Molecular Internal Rotations PR58 6.3. Chemical Reactions PR58 7. Dynamical Variants PR62 7.1. Quantum Fluid Density Functional Theory PR62 7.2. Atom-Field Interactions PR62 7.3. Ion-Atom Collisions PR62 7.4. Chemical Kinetics PR62 8. Spin Dependent Generalizations PR63 8.1. {N, Ns, v(r b)} Representation PR63 8.2. {NR, N , v(r b)} Representation PR64 9. Conclusions PR65 10. Abbreviations and Symbols of Some Important Subjects/Quantities PR
251 citations
TL;DR: In this article, the B3LYP and MP2 levels of theory using the 6-311+G(d,p) basis set were used to study the hydrogen trapping ability of various metal-ethylene complexes.
Abstract: Hydrogen trapping ability of various metal–ethylene complexes has been studied at the B3LYP and MP2 levels of theory using the 6-311+G(d,p) basis set. Different global and local reactivity descriptors and the associated electronic structure principles provide important insights into the associated interactions. There exist two distinct classes of bonding patterns, viz., a Kubas type interaction between the metal and the H2 molecule behaving as a η2-ligand and an electrostatic interaction between the metal and the atomic hydrogens.
40 citations
TL;DR: In this article, a new class of annulated imidazolium scffords 2a, 2b, 2c and their Hg(II)-NHC complexes 3a, 3b and 3c have been synthesized and characterized by different spectroscopic techniques.
34 citations
TL;DR: Conceptual DFT-based reactivity descriptors and the associated electronic structure principles lend additional support towards understanding the stability of metal clusters upon hydrogen doping.
Abstract: Structure, stability and reactivity of several metal clusters with or without hydrogen doping were studied using standard ab initio and density functional theory (DFT) calculations. Conceptual DFT-based reactivity descriptors and the associated electronic structure principles lend additional support towards understanding the stability of metal clusters upon hydrogen doping. Related aromaticity was analyzed through nucleus-independent chemical shift values. Site selectivity towards electrophilic and nucleophilic attacks were analyzed in terms of the corresponding local reactivity descriptors. Most of the metal clusters have the capacity to trap hydrogen molecules.
31 citations
TL;DR: Theoretical investigation on planar N 6 4 - and N 4 2 - rings has been performed in this paper, where the authors analyzed the aromaticity of the rings through their nucleus independent chemical shift (NICS) values as well as the σ-and π-contribution of the Z-component of the induced magnetic field.
23 citations
TL;DR: Hydrogen storage capacity of some Li(+)/F(-) doped neutral and charged aromatic/antiaromatic systems is studied at the B3LYP, M05-2X, MPW1K and MP2 levels of theory and it is observed that there is a direct bearing of the hydrogen adsorption capability on the aromaticity and or the charge of the system.
Abstract: Hydrogen storage capacity of some Li+/F− doped neutral and charged aromatic/antiaromatic systems is studied at the B3LYP, M05-2X, MPW1K and MP2 levels of theory Various conceptual density functional theory based global and local reactivity descriptors, nucleus independent chemical shift (NICS), NICS-rate, interaction energy per H2 molecule, reaction enthalpy and reaction electrophilicity are used for this purpose It is observed that there is a direct bearing of the hydrogen adsorption capability on the aromaticity and/or the charge of the system (or the charge on a specific center) The latter quantities do also change on gradual hydrogen loading
23 citations
TL;DR: Although several important insights into the counter-ion effects are obtained, much needs to be done in order to have a transparent idea therein.
Abstract: The effect of counterions on the bonding, stability and aromaticity of trigonal dianion metal clusters has been analyzed through the behavior of various conceptual density functional theory based reactivity descriptors and the nucleus independent chemical shift calculated at different levels of theory, comprising one-determinant approaches and beyond (QCISD, CASSCF(8,8) and NEVPT2), for a proper benchmarking. Although several important insights into the counter-ion effects are obtained, much needs to be done in order to have a transparent idea therein.
20 citations
TL;DR: Con conceptual DFT-based reactivity descriptors and the associated electronic structure principles are used to lend additional support to the structure, stability, and reactivity of B12N12 clusters with hydrogen doping.
Abstract: Standard ab initio and density functional calculations are carried out to determine the structure, stability and reactivity of B 12 N 12 clusters with hydrogen doping. To lend additional support conceptual DFT based reactivity descriptors and the associated electronic structure principles are also used. Related cage aromaticity of this B 12 N 12 and nH 2 @B 12 N 12 are analyzed through the nucleus independent chemical shift values. Keywords: hydrogen storage; metal cluster; conceptual DFT; aromaticity (Published: 26 April 2011) Citation: Nano Reviews 2011, 2 : 5767 - DOI: 10.3402/nano.v2i0.5767
19 citations
TL;DR: In this paper, the perturbed pericyclic isomerizations at B3LYP level with 6-31G(d) and 6-311 G(d,p) basis sets reveal that hetero- atoms significantly lower the barrier and alter the reaction free energies.
10 citations
01 Jan 2011
TL;DR: Three QSTR models for predicting the toxicity of halogen, sulfur and chlorinated aromatic compounds are developed and the potential of net electrophilicity index to act as descriptor in development of QSAR model is discussed.
Abstract: In this paper, quantitative-structure-toxicity-relationship (QSTR) models are developed for predicting the toxicity of halogen, sulfur and chlorinated aromatic compounds. Two sets of compounds, containing mainly halogen and sulfur inorganic compounds in the first set and chlorinated aromatic compounds in the second, are investigated for their toxicity level with the aid of the conceptual Density Functional Theory (DFT) method. Both sets are tested with the conventional density functional descriptors and with a newly proposed net electrophilicity descriptor. Associated R2, R2 CV and R2 adj values reveal that in the first set, the proposed net electrophilicity descriptor (Δω ± ) provides the best result, whereas in the second set, electrophilicity index (ω) and a newly proposed descriptor, net electrophilicity index (Δω ± ) provide a comparable performance. The potential of net electrophilicity index to act as descriptor in development of QSAR model is also discussed.
9 citations
TL;DR: In this article, a Hammett-type relationship has been obtained for a set of substituted benzoic acids, in terms of the net electrophilicity index, which can properly describe whether a Diels-Alder type reaction would follow a polar stepwise pathway or a non-polar-concerted mechanism.
01 Sep 2011
TL;DR: Aromaticity is one of the most fascinating popular qualitative chemical concepts in chemistry as discussed by the authors, and it has been shown that benzene is much less reactive than the related unsaturated aliphatic compounds.
Abstract: Aromaticity is one of the most fascinating popular qualitative chemical concepts in chemistry1–4. Michael Faraday5 isolated benzene by distillation in 1825. He noticed that although benzene is an unsaturated compound with H : C :: 1 : 1 it is much less reactive than the related unsaturated aliphatic...