Experimental and theoretical investigation of the spectroscopic properties of some aromatic compounds

In this study, spectroscopic properties of Ethyl 6-Chloronicotinate, Methyl 4-Bromo-2-Chloronicotinate, Methyl-5-Bromo-2-Chloronicotinate (E6ClN, M4B2ClN, M5B2ClN) molecules, which are located in the aromatic compound classes, were studied experimentally and theoretically for the first time. After determining the most stable structures of the molecules, molecular structures, vibration frequencies, electronic properties, thermodynamic properties were calculated theoretically. All theoretical calculations of these molecules were performed by using DFT / B3LYP method and 6-311 ++ G (d, p) basis set. In order to evaluate experimental results with the theoretical results, Fourier Transform Infrared (FTIR), Fourier Transform Raman (FT-Raman), Nuclear Magnetic Resonance (NMR), and Ultraviolet (UV) spectra of the compounds were recorded. Assigments of the fundamental vibrational modes of the molecules were made according to the potential energy distribution (PED). As a result of these studies the theoretical and experimental data were found to be in a good aggrement.