The nature of the NO-bond in the N-oxide group was investigated by means of combined theoretical calculations (including QTAIM and NBO approaches) and statistical analyses of the contents of crystal structure databases. The N-O bond in the N-oxide group should be classified as the NO donating bond with an important contribution of ON back-donation (of the π-electron type, when available). The v...

In this paper, we report the geometries and properties of 48 molecular species located on the MP2/6-311++G(d,p) PES of the fluorocarbene-(methanol)3 system. The structures were found by a combination of a stochastic search method, using a modified Metropolis acceptance test, and some hand constructed very symmetrical structures. We use several theoretical descriptors to categorize these species...

The metal-ligand, M-L, bonding situation in cyclic trinuclear complexes, CTCs, of copper(I), silver(I), and gold(I) was investigated in terms of the energy decomposition analysis (EDA-NOCV) and natural bond orbitals (NBOs). The anisotropy of the induced current density (ACID) and magnetic response were employed to evaluate the effect of electronic conjugation and metal-metal interactions in CTC...

The metal coordination and spin state of the Fe(III) center in nitrile hydratase (NHase) has stimulated the synthesis of model complexes in efforts to understand the reactivity and spectroscopic properties of the enzyme. We report density functional theory (DFT) calculations on a number of Fe(III) complexes that have been prepared as models of the NHase metal center, together with others having...

Complexes (H(2)O/CO(2), e-(H(2)O/CO(2)) and h(+)-(H(2)O/CO(2))) in the reaction system of CO(2) photoreduction with H(2)O were researched by B3LYP and MP2 methods along with natural bond orbital (NBO) analysis. Geometries of these complexes were optimized and frequencies analysis performed. H(2)O/CO(2) captured photo-induced electron and hole produced e-(H(2)O/CO(2)) and h(+)-(H(2)O/CO(2)), res...

The photophysics of a prospective drug molecule, 3,5-diiodosalicylic acid (3,5-DISA), having a wide spectrum of biological and medicinal applications, have been investigated using spectroscopic techniques and computational analyses. The remarkably large Stokes' shifts in various solvents from 3,5-DISA has been intertwined with the occurrence of an excited-state intramolecular proton transfer (E...

in this research at the first metoprolol drug and its fullerene derivative were optimized. natural bond orbital (nbo), nuclear indepndent chemical shift (nics) and finally ir calculations, for these compounds were carried out at the b3lyp/6-31g* quantum chemistry level. different parameters such as energy levels, the amount of chemical shift in different atoms, the amount of homo/lumo, chemical...

ortho Substituted (diphenylphosphoryl)-, (diphenylphosphorothioyl)- and (diphenylphosphoroselenoyl)-phosphinic amides o-C6H4(P(X)Ph2)(P(O)N(i)Pr2) (X = O (20a), S (20b), Se (20c)) were synthesized by ortho directed lithiation of N,N-diisopropyl-P,P-diphenylphosphinic amide (Ph2P(O)N(i)Pr2) followed by trapping with Ph2PCl and subsequent oxidation of the o-(diphenylphosphine)phosphinic amide (19...

The 6-311G(d,p) and SDD basis sets have been used to calculate the vibration frequencies, DFT/B3LYP approach was optimize structure. energy gap of molecule has calculated using lowest unoccupied molecular orbital (LUMO) with highest occupied (HOMO). stability charge delocalization Title investigated natural bond (NBO) analysis. dipole moment, polarizability, first-order hyperpolarizability, as ...