Spectroscopic, structural, electronic and bioactive characteristics of 3,5-bis(2,5-dimethylphenyl)pyridine (1): An experimental and theoretical investigations

Abstract

3,5-bis(2,5-dimethylphenyl)pyridine (1); a novel derivative of 3,5-dibromopyridine was synthesized via Pd(0) catalyzed cross coupling reaction. The compound under investigation was characterized by XRD and different spectroscopic techniques. Density functional theory (DFT) was applied to compound 1 and experimental XRD data and DFT data are found in good agreement with each other. Calculated FT-IR results are found to be in excellent agreement with experimental FT-IR findings. Chemical shift values for NMR were calculated for compound (1) in the gas phase which show deviation to experimental values might be because of medium affects. Natural bond orbital (NBO) study was also performed which indicates that the methyl groups influence van der Waals interactions among the adjacent bonds, especially, delocalization of energy during the interaction. Energy gap values of HOMO-LUMO calculated through frontier molecular orbital (FMO) analysis provided enough evidence that molecule is biologically active. Molecular electrostatic potential (MEP) mapping indicated that electron density is located on nitrogen whereas carbon and hydrogen atom are favorable sites for nucleophilic attack. Moreover, the bioactivities of compound (1) have been confirmed by the experimental activity in terms of zones of inhibition against bacteria and fungus.