FT-IR spectroscopy combined with DFT calculation to explore solvent effects of vinyl acetate

• ν(CO) of VAc is employed to reflect chemical reactivity of CC group in VAc.
• Correlations between the νcal(CO) and solvent parameter equations suggest limitation of using the PCM model.
• Long-range electrostatic solvation free energies of VAc are calculated by the SMD model.
• Ab initio calculation allow assignments of the νexp(CO) in alcohol solvents.

The infrared vibration frequencies of vinyl acetate (VAc) in 18 different solvents were theoretically computed at Density Function Theory (DFT) B3LYP/6-311G* level based on Polarizable Continuum Model (PCM) and experimentally recorded by FT-IR spectroscopy. The solvent-induced long-range bulk electrostatic solvation free energies of VAc (ΔGelec) were calculated by the SMD model. The CO stretching vibration frequencies of VAc were utilized as a measure of the chemical reactivities of the CC group in VAc. The calculated and experimental CO stretching vibration frequencies of VAc (νcal(CO) and νexp(CO)) were correlated with empirical solvent parameters including the KBM equation, the Swain equation and the linear solvation energy relationships (LSER). Through ab initio calculation, assignments of the two CO absorption bands of VAc in alcohol solvents were achieved. The PCM, SMD and ab initio calculation offered supporting evidence to explain the FT-IR experimental observations from differing aspects.

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