DFT and <i style="">ab-initio</i> study of structure of 1,4-dichloro-2-nitrobenzene

673-678The vibrational spectroscopy of 1,4-dichloro-2-nitrobenzene (DCNB) by means of quantum chemical calculations has been studied. The FT-Raman and FT-IR spectra of DCNB have been recorded in the region 3500-50 cm-1 and 4000-400 cm-1, respectively. The fundamental vibrational frequencies and intensity of vibrational bands have been evaluated using density functional theory (DFT) with standard B3LYP/6-311+G (d,p) and B3LYP/6-311++G (d,p) basis set combinations for optimized geometries. The observed FT-IR and FT-Raman vibrational frequencies have been anlaysed and compared with theoretically predicted vibrational frequencies. The assignments of bands to various normal modes of molecule have also been carried out