FTIR study of hydrogen bonding interactions between alkyl esters and hexanol, p-cresol in carbon tetrachloride

The effect of hydroxyl group in hexanol and p-cresol on the carbonyl vibration of representative compounds belonging to methyl methacrylate, ethyl methacrylate and butyl methacrylate in carbon tetrachloride has been studied by FTIR spectroscopic method. The integrated intensities and change in dipole moments for O-H and C=O bonds were calculated. Utilizing Nash method, the formation constant and free energy of the 1:1 complexes have been calculated. The formation constant and free energy change values vary with chain length of acrylic esters, which suggests that the strengths of the intermolecular hydrogen bonds (O–H...O=C) are dependent on chain length of acrylic esters. The strength of the intermolecular C=O: HO bonds is shown to be dependent on the basicity of the C=O group of alkyl esters and the acidity of the proton donor.