Theoretical thermodynamic study of Pyrazole in the gas phase at the different temperatures

Abstract

The thermodynamic functions such as enthalpy (H), Gibbs free energy (G) and entropy (S) of<br />Pyrazole was theoretically studied at 5 different temperatures 25, 30, 35, 40 and 45°C by using<br />Gussian o3, software. First, the structural optimization of isolated Pyrazole was done in the gas phase<br />by appling the Density Functional Theory (B3LYP) level with 3-21G, 6-31G and 6-31+G(d) basis<br />sets. Moreover, vibrational frequencies were calculated in gas phase on the optimized geometries at<br />the same level of theory to obtain enthalpy, Gibbs free energy and entropy at 5 different<br />temperatures.Finally the temperature effects on the thermodynamic functions were discussed.