Journal of Physical and Theoretical Chemistry
Volume:11 Issue: 2, Summer 2014

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.

The methamphetamine has been studied theoretically at the MP2 [1]/6-31G[2] level in gas phase.Methamphetamine has been investigated Via NMR, Frequencies Calculation and NBO analysis. Thestructure of methamphetamine was designed primarily using of Chem. Bio Draw and it geometry hasbeen optimized at the MP2/6-31G computational level. The present work consists the study of themethamphetamine reported in Fig1. Frequencies calculations have been carried out to confirm thatthe structure obtained correspond to energetic minima. The all calculations have been performed withthe Gaussian-03 program [3].

Alcohol oxidation is an important reaction in organic syntheses. Some of these reactions must beunder difficult conditions in respect of high temperature and pressure. In many cases, reactions areconducted by environmentally in appropriate solutions. In this study, preparing an effectivenanocatalyst and estimating the optimum provisions of its production processes are assessed. Twomajor and crucial factors of(Mn2+/Co2+)-Al2O3 catalyst are molar ratio of Mn2+/Co2+ and masspercent of Al2O3.Our experimental results showed that 1:1 molar ratio and 15% of Al2O3 by mass arefairly suitable. Prepered catalyst was used in the oxidation reaction.

The physical and chemical properties of Pyrazole and Pyrazoline molecules were theoreticallystudied by Gaussian 03, software with NMR and Molecular orbital calculations at B3LYP/6-31G andB3LYP/6-31+G(d) levels, in gas phase and solution. In this study a comparison effect of threesolvents with different dielectric constants on Pyrazole and Pyrazoline molecules in aspect energyinteraction between solute and solvent, and NMR shielding parameters (ppm) such as,
Iso (
Isotropic),
Aniso (
Anisotropic), anisotropic magnetic shielding tensor, 
, chemical shift, , totalatomic charge and asymmetry parameter, , were performed. These parameters were calculated byusing the GIAO method. The results show solvent-induced shielding variation is more stronglyrelated to the intensity of the solvent reaction field rather than on the change of molecular geometryinduced by the solvent.

DFT calculations were applied to evaluate the electronic and magnetic properties of zigzag BC2Nnanotubes based on the 13C, 15N, and 11B NMR parameters and natural charge analysis. Weconsidered three types of zigzag nanotubes, ZZ-1, ZZ-2, and ZZ-3 (n, 0) with n = 8, 12, and 14. Theobtained results indicated the divisions of the electrostatic environments around C nuclei into a fewlayers, consistent with the calculated natural charges on C atoms. There was a good correlationbetween the layers of chemical shielding isotropy as well as anisotropy, >iso, and ?>, and the fivelocal structures around carbon atoms. Successive BN units lead to larger 15N >iso values incomparison with the individual BN units in the ZZ-2(n, 0) and ZZ-3(n, 0)). Slight differences in thevalues of 11B >iso clarified diminutive diversity in the electron densities of boron nuclei, while ?>values indicated the more apparent range of changes.

The structure and properties of niobapyrimidinium complex were examined by density functionaltheory method (mpw1pw91). The effect of solvent on the structural parameters, frontier orbitalenergies and hyperpolarizability (
tot) of this molecule has been explored. The thermodynamicproperties of the title compound at different temperatures have been calculated. Also, the parasubstitutionseffect on the structure, frontier orbital energies, aromaticity and hyperpolarizability (
tot)has been studied. Nucleus independent chemical shift (NICS) values show that these species arearomatic.