Key points are not available for this paper at this time.
Abstract The tautomeric behaviour of five secondary phosphane oxides (SPOs) with different electronic properties has been investigated by NMR and IR spectroscopy, density functional theory calculations and X‐ray structural analysis. Proof is given that only with strong electron‐withdrawing groups on the phosphorus atom can the relevant trivalent phosphinous acid be observed in the equilibrium, whereas in the case of electron‐rich phosphane oxides the pentavalent species dominates. For a detailed analysis of the IR spectra, the deconvolution programme BTEM has been successfully applied.
Christiansen et al. (Wed,) studied this question.