Vol. 6, Issue 1, Part A (2024)

Ground state geometry, molecular properties and electronic structure for Benidipine and Benidipine Hydrochloride in gas, octanol, DMF and water phase were reported at B3LYPl evel. 6-311G (d,p), 6-311++G (d,p) and, 6-311++G (2d,2p) basis sets were used for Benipidine and only 6-311G (d,p) basis set was used for Benidipine Hydrochloride. The NBO analysis were performed to understand the intra-molecular delocalization along with the inter-molecular interaction. The effects of solvents such as DMF, octanol, and water on the optimized geometry and intra-molecular delocalization of Benidipine and Benidipine Hydrochloride molecules were evaluated. Electronic properties of the title compound such as frontier orbitals and their corresponding energy gap were calculated by DFT approach. Solvation free energy values in different solvents decrease in the order water > DMF > n-octanol, and HOMO-LUMO energy gap values follow the order of gas > octanol > DMF > water for BEN and BENHCl molecule.
Thermodynamic parameters such as SEZPE,:SETE,: SETEmt and SETFE values, Rotational constants, Entropy, Thermal Energy and Thermal Capacity, as well as the change of thermodynamic properties such as the heat capacity, entropy, enthalpy, Gibba free energy in the temperature range of 200-1000 K were calculated from the data obtained by DFT.