The conformational stability and vibrational infrared and Raman spectra of trichloroacetyl isocyanate (CCl3CONCO) were investigated by ab initio MP2 and density functional B3LYP calculations using the 6-311++G** basis set. From the potential energy scans of the internal rotations in both the halomethyl and the isocyanate rotors, the molecule was predicted to exist predominantly in the cis-cis c...

The 1,3-dipolar cycloaddition of azomethine ylides bearing the biologically active 1,4-dihydropiridine ring to C(60) was investigated by means of quantum mechanical calculations at the semiempirical AM1 and DFT (B3LYP/6-31G) methods. The presence of two chiral centers and one chiral axis in the resulting fulleropyrrolidines leads to four possible [6,6] cycloaddition products. Formation of atrop...

A detailed analysis of the selected DFT functionals for the calculations of interaction-induced dipole moment, polarizability and first-order hyperpolarizability has been carried out. The hydrogen-bonded model chains consisting of HF, H(2)CO and H(3)N molecules have been chosen as a case study. The calculations of the components of the static electric properties using the diffuse Dunning's basi...

Several DFT functionals have been carried out to study the first hyperpolarizabilities βHRS of push-pull polyene as a function basis sets, electron correlation, size, frequency dispersion and geometry. These calculations confirm huge effects Møller– Plesset (MP2) results reproduces values hyperpolarizability obtained with reference CCSD(T) level. Among density functional theory exchange- correl...

DFT B3LYP/6-31G(d,p) calculations were performed to describe the proton transfer reaction pathway in the 2,6-dichlorophenolate of pyridine. The aim of these calculations was to establish the character of the dependence of the structure parameters on the proton transfer and comparing the results with known structures, e.g. the 2,6-dichloro-4-nitro- and pentachlorophenolates of pyridines. To make...

The relative stability of the different tautomers of hydantoin has been studied through the use of DFT method. The structures and the vibrational frequencies of all stable tautomers and all the transitions states connecting between them have been calculated at the B3LYP/6-311+G(d,p) level of theory in the gas phase and selected solvents using IE-PCM model. Final energies have been obtained in s...

A simple, efficient, and mild procedure for a solvent-free one-step synthesis of various 4,4'-diaminotriarylmethane derivatives in the presence of antimony trichloride as catalyst is described. Triarylmethane derivatives were prepared in good to excellent yields and characterized by elemental analysis, FTIR, (1)H and (13)C NMR spectroscopic techniques. The structural and vibrational analysis we...

DFT(B3LYP, B3PW91) calculations in conjunction with three different basis sets have been utilized to investigate the variations in the bond lengths, dipole moment, rotational constants, IR frequencies, IR intensities and rotational invariants of ClCCCN. The nuclear quadrupole constants of chlorine ((35)Cl, (37)Cl) and nitrogen ((14)N) of ClCCCN have been calculated on the experimental r(s) stru...

Density-functional-based and ab initio calculations were implemented at different computational levels to estimate the binding energy of Zn2+ ion adsorbed on the available sites of a silicate MEL-type adsorbent. B3LYP and MP2 were used in combination with the 6-31G*, 6-31+G*, LanL2DZ, 6-311+G*, and Def2-TZVP basis sets. The zinc cation was found to preferentially occupy the 6MR sites followed b...

Relative populations of the three energy-lowest IPR (isolated-pentagon-rule) isomers Ho@C 82 under high-temperature synthetic conditions are computed using Gibbs energy based on characteristics from density functional theory calculations (B3LYP/3-21G ∼ SDD entropy term, B3LYP/6-31G* energetics). Two major species predicted, Ho@ C 2 v ; 9-C and s ( c ); 6-C , with rather comparable supposed temp...