THEORETICAL-STUDIES OF POSSIBLE PROCESSES FOR THE INTERSTELLAR PRODUCTION OF PHOSPHORUS-COMPOUNDS - REACTION OF P+ WITH WATER

A theoretical ab initio molecular orbital study of the reaction of P+ with H2O has been carried out. We have found this reaction to be endothermic for the production of PO+ and HPO+ by 30 and 26 kcal/mol, respectively, at correlated levels. On the other hand, the production of POH+ is found to be exothermic (by approximately 10 kcal/mol). In addition, there is a two-step path toward the formation of POH+ which is found to proceed with no activation energy. This involves isomerization of the POH2+ ion-molecule complex to form HPOH+, and subsequent hydrogen abstraction from this isomer. Therefore, the reaction of P+ with H2O seems to be feasible under interstellar conditions, but only toward the production of POH+.