Quantum chemical study of benidipine molecule

Benidipine hydrochloride is a calcium channel blocker antihypertensive drug. The ground state geometry, molecular properties and electronic structure of Benidipine and Benidipine Hydrochloride in gas, n-octanol, DMF and water phase were reported at B3LYP level. While 6-311G(d,p), 6-311++G(d,p) and 6-311++G (2d,2p) basis sets were used for Benipidine, only 6-311G(d,p) basis sets were used for Benidipine Hydrochloride set was used. The properties of aromaticity, natural bond orbital (NBO) and Nonlinear Optical (NLO) parameters of Benidipine and Benidipine Hydrochloride compounds were investigated theoretically using the density functional theory (DFT) electronic structure method. The effects of solvents such as DMF, n-octanol, and water on the optimized geometry and intramolecular delocalization of Benidipine and Benidipine Hydrochloride molecules were evaluated. Solvation free energy values in different solvents decreased in the order of water > DMF > n-octanol and HOMO−LUMO energy gap values for BEN and BENHCl molecules were reported to follow the order of gas > n-octanol > DMF > water. Thermodynamic parameters such as SEZPE,:SETE,: SETEmt and SETFE values, Rotational constants, Entropy, Thermal Energy and Thermal Capacity, as well as the temperature change of thermodynamic properties such as heat capacity, entropy, enthalpy, Gibbs free energy were calculated from the data obtained by DFT. NLO parameters such as dipole moment, polarization and first-order hyperpolarization values of BEN and BENHCl compounds were also examined.