Afinidades eletrônicas de doze moléculas pequenas foram calculadas pela teoria de funcional de densidade empregando dois funcionais diferentes(B88-P86 e B3LYP) combinados com três conjuntos de bases diferentes(6-31++G**, 6-311++G** e aug-cc-pVTZ). O método de função de Green para camada na valência exterior também foi empregado para os cálculos de afinidades eletrônicas das moléculas. Duas melh...

1,1-Dimethyl-3-oxo-1,4-diazepan-1-ium chloride (1) and 1,1-dimethyl-1-carboxymethyl-3-aminopropyl ammonium hydrochloride (2) have been obtained by the reactions of 1,1-dimethyl-1,3-propylenediamine with ethyl chloroacetate and chloroacetic acid, respectively. The products have been characterized by FTIR, Raman and NMR spectroscopy. B3LYP calculations have also been carried out. The screening co...

There have been many comparisons of computational methods applied to ground states, but studies of organic reactions usually require calculations on transition states, and these provide a different test of the methods. We present calculations of the geometries of nineteen covalent-bond forming transition states using HF and twelve different functionals, including GGA, hybrid-GGA and hybrid meta...

the armaticity of 5 methylcytosine tautomers in the gas phase has been studied and the chemical structures of related tautomers are investigated . the electronic energy, enthalpy and free energy of each tautomer are also estimated at the b3lyp/6-31 g* // b3lyp/6-31 g* and mp2 / 6-31 g* // mp2 / 6-31 g* levels

the dopamine has been studied theoretically at the b3lyp/6-31g* level were performed in gasphase. we calculated physical parameters like atomic charges, energy (=>), asymmetry parameter(?), chemical shift @iso, dipole moment and isotropic nmr determinant and in this work we usedgaussian 03 at nmr and calculation by using b3lyp methods with 6-31g* basis set.

Theoretical investigations of the interaction between dapivirine and the HIV-1 RT binding site have been performed by the ONIOM2 (B3LYP/6-31G (d,p): PM3) and B3LYP/6-31G (d,p) methods. The results derived from this study indicate that this inhibitor dapivirine forms two hydrogen bonds with Lys101 and exhibits strong π-π stacking or H…π interaction with Tyr181 and Tyr188. These interactions play...

Mercaptopurine is a medicine used to prevent the formation and spread of cancer cells. Mercaptopurine, known chemically as 1,7-dihydro-6H-purine-6-thione, is an analogue of the purine bases adenine and hypoxanthine. This work reports an investigation of anticancer drug Mercaptopurine with the combined density functional theory and Its structure were optimized at B3LYP/6-31G*, level and The mole...

The armaticity of 5 methylcytosine tautomers in the gas phase has been studied and the chemical structures of related tautomers are investigated . The electronic energy, enthalpy and free energy of each tautomer are also estimated at the B3LYP/6-31 G* // B3LYP/6-31 G* and MP2 / 6-31 G* // MP2 / 6-31 G* Levels

Vibrational studies of amino acids experimentally and theoretically have been performed. The Semi-empirical methods optimization by PM6 and RM1 on the land d-amino acids (alanine, phenylalanine, aspartic and glutamic acid), showed no difference in energy between l-and d-isomers. The vibrational frequencies were calculated by semi-emprical methods (PM6 and RM1) and ab initio methods (B3LYP/6-31+...