Carbamoylphosphinidene: A Phosphorus Analogue of Carbonyl Nitrene.

Carbonyl nitrenes are versatile intermediates that have been extensively characterized; however, their phosphorus analogues remain largely unknown. Herein, we report the observation of a rare example of carbonyl phosphinidene NHC(O)P, which was generated through the photolytic (193 nm) dehydrogenation of phosphinecarboxamide (NHC(O)PH) in a solid N-matrix at 12 K. The characterization of NHC(O)P in the triplet ground state with matrix-isolation IR and ultraviolet-visible (UV-vis) spectroscopy is supported by comprehensive isotope labeling experiments (D and N) and quantum chemical calculations. Upon visible-light irradiation at 680 nm, NHC(O)P inserts into dihydrogen by the reformation of NHC(O)PH with concomitant isomerization to the more stable aminophosphaketene (NHPCO). Additionally, the photoisomerization of NHC(O)PH to NHC(OH) = PH along with decomposition by yielding hydrogen-bonded complexes HNCO···PH and HPCO···NH has been observed in the matrix.