Infrared solvent shifts and molecular interactions. Part IX. P–H and PO dipoles and the hydrogen-bonding ability of the P–H group

Abstract

The effect of solvent on the P–H stretching mode of diphenylphosphine and the P–H and PO stretching modes of a series of phosphonates has been studied. The solvent dependency of ν(PO) is similar to that of other ν(XO) but that of ν(P–H) does not follow the pattern of other ν(X–H) frequencies. It is concluded that the P–H group in these compounds is barely capable of forming hydrogen bonds. The spectra confirm the keto-structure of phosphonate esters; the doublet nature of ν(PO) is considered to arise from rotational isomers.