The hypothetical PH5 molecule and its reaction to PH3+H2

The molecule PH5 is interesting because it is the prototype of phosphoranes and moreover of systems with pentavalent phophorous. PH5 is the simplest of all electron rich (hypervalent) molecules. This paper discusses the question of the metastability of PH5 and studies the equilibrium structure and the force field. The potential hypersurface for the reaction PH5 to PH3+H2 is discussed. The author comments on bimolecular and auto-catalytic desintegration processes, hyperfine structure, and on the chances of whether PH5 will ever be observed experimentally. It is shown that if there were only the concerted decomposition possible, PH5 should be kinetically quite stable