A study of the molecular, vibrational, electronic and quantum chemical investigation of 2-methyl-1-vinylimidazole

• The FT-IR and FT-Raman spectra of 1-methyl-2-imidazolethiol have been recorded.
• The temperature dependence of the thermodynamic properties was investigated.
• The atomic charges and charge delocalization of the molecule have been analysed.
• The reactivity sites have been identified by MESP analysis.
• NMR spectra have been investigated.

The spectroscopic properties of 2-methyl-1-vinylimidazole (abbreviated as 2M1VIM) were examined by FT-IR, FT-Raman and NMR techniques. FT-IR and FT-Raman spectra were recorded in the region 4000–400 cm−1 and 3500–50 cm−1, respectively. The 1H and 13C NMR spectra were recorded in CDCl3. The structural and spectroscopic data of the molecule in the ground state were calculated by using density functional theory (DFT) employing B3LYP and LSDA methods with 6-311++G(d,p) basis set. The geometry of the molecule was fully optimized, vibrational spectra were calculated and fundamental vibration were assigned on the basis of potential energy distribution (PED) of the vibrational modes calculated with scaled quantum mechanical (SQM) method. The optimized structure of the compound was interpreted and compared with the reported experimental values. The observed vibrational ware numbers, absorption wavelengths and chemical shifts were compared with calculated values. The calculated HOMO and LUMO energies show that charge transfer occur within the molecule. As a result, the optimized geometry, and calculated spectroscopic data show a good agreement with the experimental results.

The spectroscopic properties of the title compound 2-methyl-1-vinylimidazole (2M1VIM) led to the complete FT-IR and FT-Raman vibrational studies, calculation of HOMO–LUMO, NBO analysis and molecular electrostatic potential (2M1VIM). The temperature dependence of thermodynamic properties has been analysed. The values of the total dipole moment (μ) and the first order hyperpolarizability (β) of the investigated compound were computed using B3LYP/6-311++G(d,p) calculations. The 13C and 1H nuclear magnetic resonance (NMR) chemical shifts of the molecule have been recorded.Figure optionsDownload as PowerPoint slide