Structural characteristics and harmonic vibrational analysis of the stable conformer of 2,3-epoxypropanol by quantum chemical methods

The FT-IR and FT-Raman spectra of H bond inner conformer of 2,3-epoxypropanol have been recorded in the regions 3700–400 and 3700–100 cm−1, respectively. The spectra were interpreted in terms of fundamentals modes, combination and overtone bands. The normal coordinate analysis was carried out to confirm the precision of the assignments. The structure of the conformers H bond inner and H bond outer1 were optimised and the structural characteristics were determined by density functional theory (DFT) using B3LYP and MP2 methods with 6-31G∗∗ and 6-311++G∗∗ basis sets. The vibrational frequencies were calculated in all these methods and were compared with the experimental frequencies which yield good agreement between observed and calculated frequencies. The electronic properties HOMO and LUMO energies were measured by time-dependent TD-DFT approach.

Graphical abstractThe conformational analysis of 2,3-epoxypropanol were performed. The structure of the conformers H bond inner and H bond outer1 were optimised and the structural characteristics were determined by DFT and MP2 methods with 6-31G∗∗ and 6-311++G∗∗ basis sets. The complete vibrational assignment and analysis of the fundamental modes of the most stable conformer H bond inner was carried out using the experimental FTIR and FT-Raman data, and quantum mechanical studies.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► FTIR and FT-Raman investigations of 2,3-epoxypropanol were carried out. ► The conformational analysis of this compound was performed. ► Energy, structural, thermodynamical characteristics H bond inner and H bond outer1 conformers were determined. ► The electronic properties and NBO analysis were carried out. ► Steric effect of hydroxymethyl group on the epoxy ring parameters has been analysed.