Study of phosphorus acid amides in the condensed state by the IR spectroscopy method

1. The IR spectra of some phosphorus acid amides and their deutero analogs were measured in the condensed state in the 700–4000 cm−1 region, and an assignment of the frequencies of the absorption bands was made. 2. In the condensed state the phosphorus acid amides form an intermolecular hydrogen bond via the N-H protons of the amide groups and the oxygen of the P=O group.