Density Functional Theory Study of Solvent Effects on 3-Fluoro-, 3-Chloro-, 3-Bromopyridine

Optimized molecular structures and total energies of 3-fluoro-, 3-chloro-, 3-bromopyridine (3‑FP, 3-CP, and 3-BP) molecules in vacuum, benzene, toluene, chloroform, dichloromethane, ethanol, dimethylsulfoxide and water media were investigated using DFT/B3LYP-6311++G(d,p) method. Moreover, in order to be able to see the effects of changing physical conditions, the thermochemical properties of the structures have been calculated in different temperatures and solvent media. Vibrational frequencies of 3-FP, 3-CP, and 3-BP molecules in vacuum and solvent media were calculated and compared to experimental data from the literature. Also, the chemical reactivities of the structures were calculated from HOMO–LUMO energies. Molecular electrostatic potential maps were plotted and atomic charges of each atom were determined. As a result of the study, it was determined that the molecular parameters of these three structures were slightly influenced by the changing solvent polarity, but the vibration frequencies and other chemical properties have very seriously affected.