Vibrational spectroscopy and density functional theory study of 4-mercaptophenol.

In this paper, 4-mercaptophenol (4-MPH) was designed as a model molecule for theoretical and experimental studies of the molecule structure. Density functional theory (DFT) calculations have been performed to predict the IR and Raman spectra for the molecule. In addition, Fourier transform infrared (FTIR) and Raman spectra of the compound have been obtained experimentally. All FTIR and Raman bands of the compound obtained experimentally were assigned based on the modeling results obtained at the B3LYP/6-311+G(**) level. Our calculated vibrational frequencies are in good agreement with the experimental vales. The molecular electrostatic potential surface calculation was performed and the result suggested that the 4-MPH has two hydrogen bond donors and three hydrogen bond acceptors. HOMO-LUMO gap was also obtained theoretically at B3LYP/6-311+G** level.