Theoretical study of solvent effect on NMR shielding for Pyrazole and Pyrazoline
الموضوعات : Journal of Physical & Theoretical Chemistry
Farideh Keshavarz Rezaei
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الکلمات المفتاحية: Pyrazole, Pyrazoline, NMR shielding, Solvent effects,
ملخص المقالة :
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.
