Investigation of molecular features of some pharmacological compounds with potential anti-cancer property by using density functional theory method

The purpose of this study is to determine the most stable states, conformations and electronic properties of N-cyclohexyl -5 - ((2-phenyl-1H-benzo [d] imidazol-1-yl) methyl) -1,3,4-oxadiazole-2-amine (1), 2- (4-chlorophenyl) (2), 2- (4-methoxyphenyl) (3), 2- (3,4-dimethoxyphenyl) (4) and 2- (3,4-dibenzyloxyphenyl) (5) molecules with potential anticancer property by using density functional theory method. Since only suitable crystals belonging to molecule 1 can be obtained from five molecules, the structure of this molecule was investigated by X-ray diffraction method. The Bragg reflection intensities used in the structural solution of this molecule were collected by Bruker APEX-II CCD diffractometer. The collected data were used in the structure solution by using SHELXS-97 and SHELXL-97 programs included in the WinGX package program. Thus, parameters related to molecular geometry such as bond length, bond angle, torsion angle and dihedral angle of the molecule were determined. While using GausView 5.0 program for drawing the model geometries; Gaussian 09W program was used for quantum mechanical calculations. In this program, calculations were made by using density functional theory methods. Energy optimizations were made at B3LYP / 6-31G (d, p) level. In addition, it was determined whether the molecules have been at a global minimum (whether the molecules have no negative frequency) by calculating individually frequencies at the stationary points on potential energy surface. Conformational analysis of all molecules was performed by making one and two dimensional scans around single bonds. In this way, their most stable states were determined.