Effect of solvent and temperature on OH stretching bands produced by van der Waals interactions

Abstract

The influence of solvents which are inert or weak hydrogen-bond acceptors on the OH stretching band of t-butyl alcohol and the effect of temperature have been studied. Frequency shifts, Δν, and half-widths, Δν_1/2, change linearly with temperature. This linear relationship and the relative influence of the solvent can be described by a recently proposed model of inert liquids. This model gains importance by its effectiveness in predicting spectroscopic behaviour and is shown to increase our understanding of liquids. Van der Waals forces influence Δν, Δν_1/2 and band intensities in a similar fashion, although to a lesser extent than hydrogen bonds. The transition between inert solvents and weak hydrogen-bond acceptors is studied. The half-bandwidth provides an interesting method to differentiate between dispersion and hydrogen-bond interactions.