Conformational, structural, electronic, and vibrational investigations on 5-methyl-4-(2-thiazolylazo)resorcinol by FT-IR, FT–Raman, NMR, and DFT

Abstract

The all conformers of 5-methyl-4-(2-thizolylazo)resorcinol have been identified by Spartan 13 software. All conformers have been optimized B3LYP/6-311G (d, p) level of theory in Gaussian 09 software. According to potential energy surface search, 5-methyl-4-(2-thizolylazo)resorcinol has eight conformers. All the structural parameters of the most stable conformer of 5-methyl-4-(2-thizolylazo)resorcinol are predicted using DFT (B3LYP) method with the same basis set given above. The vibrational frequencies are recorded by the Fourier transform infrared (FT-IR 4000–550 cm−1) and Fourier transform Raman (FT–Raman; 4000–100 cm−1) spectra in the powder form. The vibrational frequencies are predicted and compared with experimental FT-IR and FT–Raman ones. The experimental 1H and 13C NMR spectra have been recorded and compared with the theoretical chemical shifts determined by the GIAO method. The results of UV–Vis spectra of molecule are also presented. Theoretical results compared with the experimental results for the identification and characterization of 5-methyl-4-(2-thizolylazo)resorcinol molecule.