DFT, FT-IR and FT-Raman investigations of 1-methyl-2-imidazolecarboxaldehyde

• The experimental and theoretical investigations of title molecule were performed.
• IR and Raman spectra of title molecule have been analyzed.
• The solvent effects are described by the SCI-PCM model successfully.
• Intermolecular hydrogen bonding between title molecule and water has been analyzed.

The FT-IR and FT-Raman spectra of 1-methyl-2-imidazolecarboxaldehyde were recorded in the region 4000–400 cm−1 and 3500–50 cm−1, respectively. Optimized geometric parameters, conformational equilibria, normal mode frequencies, and corresponding vibrational assignments of title molecule were examined by means of density functional theory (DFT) method with B3LYP/6-311++G(d,p) basis set. All vibrational frequencies were assigned in detail with the help of total energy distribution (TEDs). The results showed that the DFT/B3LYP method predics vibrational frequencies and the structural parameters effectively. Furthermore, solvent effects are investigated in different solvents (chloroform, dimethylsulfoxide and water) using the self-consistent isodensity polarizable continuum model (SCI-PCM). All results indicate that the combination of SCI-PCM model and DFT/B3LYP/6-311++G(d,p) calculation could give excellent explanations of the solvent effects. Intermolecular hydrogen bonding between 1-methyl-2-imidazolecarboxaldehyde and water was investigated using quantum chemical methods. DFT calculations were used to optimize the adducts of heterocycle with the single water molecule.