The ab initio study and NBO analysis of the solvent dielectric constant effects and the implicit water molecules on the structural stability of the 1-(6-chloroquinoxalin-2-yl)-2-(4-(trifluoromethyl)-2,6-dinitrophenyl) hydrazine

Ab initio molecular orbital (MO) and density functional theory (DFT) methods were used to analyze the structure and the relative stability of 1-(6-chloroquinoxalin-2-yl)-2-(4-(trifluoromethyl)-2,6-dinitrophenyl) hydrazine in gas phase and the different solvent media. The effects of solvent dielectric constant and the implicit water molecules were investigated on the structural stability and intramolecular interactions. All used methods revealed that by the increase of solvent dielectric constant, the relative stability of the considered compound increase. Hence, the most stable structure is perceived in aqueous solution. Furthermore, natural bond orbital (NBO) analysis demonstrated that in the presence of implicit water molecules, the lone pair electrons of nitrogen have the most contribution in the resonance interactions of the aromatic rings and their stability. These facts may be the probable reasons behind the structural stability of the considered structure in the water solution based on energetic data and NBO analysis at the microscopic level.