Experimental and DFT studies of solvent effects on molecular structure and physical properties of Dipyridylamine pyridine based ligand

Abstract

The solvent effects on molecular structure, electronic, vibrational and thermochemical properties of 2,2′-Dipyridylamine were investigated by using experimental and theoretical methods. 2,2′-Dipyridylamine molecule was selected for this study intentionally because it has two pyridyl rings connected by amine bridge. This allows to change the stable equilibrium geometry, even the slightest effects. Dichloromethane was chosen as solvent. The reason for this selection is to examine whether the chlorine atoms make hydrogen bonds with the ligand atoms. For this purpose, firstly 2,2′-Dipyridylamine solution was prepared and characterized by FT-IR and FT-Raman spectroscopy. Secondly, crystal structure of 2,2′-Dipyridylamine was obtained to compare with the calculated geometric parameters. The crystal structure was analyzed by Single Crystal X-Ray diffraction methods. Density Functional Theory calculations were conducted with B3LYP functional and 6-31G(d) basis set. The theoretical vibrational properties of optimized geometric structure were computed in vapor and solvation phases. Two different theoretical approaches were discussed, based on the experimental results. It can be seen from the experimental and theoretical studies that the structural, vibrational, thermochemical and electronic properties are dependent on the solvent effects for selected structure. Furthermore, the chlorine atoms of Dichloromethane do not make hydrogen bonds with the ligand atoms.