FT-IR, FT-Raman, NMR Spectroscopic and DFT Quantum Chemical Investigations of 6-Methylcoumarin

Abstract

The structural geometry, electronic and reactivity characteristics, vibrational assignments and the fundamental modes of 6-methylcoumarin have been carried out. The effect of methyl group on the pyrone skeletal vibrations was also discussed. The experimental vibrational frequencies were compared with the wavenumbers obtained theoretically from the B3LYP method employing the high level 6-311++G** and cc-pVTZ basis sets. Frontier molecular orbital (FMO) energy and the LUMO-HOMO energy gap was measured. The atomic charges and the bond properties were examined by natural bond orbital analysis. The hydrogen and carbon environment were examined by NMR spectra. The nuclophilic, electrophilic and free radical attacking sites of 6-methylcoumarin were also analyzed.