Hydration and Amination of Phosphorus Mononitride

As a heavy analogue of molecular nitrogen (N2), phosphorus mononitride (PN) is currently a major P-bearing interstellar species that only has fleeting existence on Earth. Chemically, PN is very reactive as demonstrated by its spontaneous oligomerization reactions, however, its reactivity toward other molecules remains scarcely explored. Herein, we present a study on the reactions of PN with water (H2O) and ammonia (NH3). Specifically, PN reacts with H2O in the gas phase to yield aminophosphinidene oxide H2NPO, which can be converted to the less stable isomers HNPOH and HP(O)NH via photoinduced hydrogen migration reactions in an Ar-matrix at 10 K. Alternatively, these PN-bearing species can be generated through photoisomerization of the least stable isomer H2PNO that can be synthesized by radical association reaction between •PH2 and •NO in the gas phase. By analogy, the reaction between PN and NH3 proceeds photolytically, yielding the N-H insertion product H2NPNH. Our results showcase the novel O/N-H insertion reactivity of PN, thereby advancing our knowledge about its astrochemical evolution in the interstellar medium (ISM).