Raman Spectroscopic Study of Acetone-Phenol Mixtures

Abstract

Acetone-phenol mixtures with phenol mole fractions in the range 0.079-0.6000 were studied by Raman spectroscopy. Spectra were obtained in the regions of acetone C=O stretching and C-C symmetric stretching bands. Principal factor analysis applied to the set of C=O stretching bands revealed two independent components belonging to free and hydrogen-bonded acetone. Interaction with phenol produces a new band at a lower wavenumber in the C=O vibration region and an additional band at a higher wavenumber in the C-C symmetric stretch region. These changes were explained by charge delocalization induced by the hydrogen bond. On applying band deconvolution and target factor analysis, it was deduced that the equilibrium constant K of 1:1 acetone-phenol complex formation is too high to be determined by Raman spectroscopy in the range 0.079-0.400 mole fraction of phenol. At equal mole fractions of acetone and phenol, values of K = 2.61 and 3.22 dm3 mol-1 were obtained by deconvolution and target factor analysis, respectively. An investigation of ternary solutions with an inert solvent showed no significant differences in acetone-phenol interaction between this system and binary mixtures. © 1998 John Wiley & Sons, Ltd.