Hydrogen bonding in some adducts of oxygen bases with acids. Part II. Infrared spectra of liquid adducts of carboxylic acids with sulphoxides, phosphine oxides, and other bases

Abstract

By variation of the proton levels of donors (mono-, di-, tri-chloroacetic acid) and acceptors (sulphoxides, phosphine oxides, a selenoxide, pyridine N-oxide) a series of adducts was obtained which made possible the investigation of the effects of increasing strength of the hydrogen bond on the spectra. The latter may be grouped into two distinct types: (i) the region 1800–3000 cm.^–1 contains three main bands connected with OH vibrations, and (ii) no such band is in this region, but a strong and broad feature appears at much lower frequencies. Possible origins of these and other spectral characteristics are discussed.