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 NH₂C(O)P, which was generated through the photolytic (193 nm) dehydrogenation of phosphinecarboxamide (NH₂C(O)PH₂) in a solid N₂-matrix at 12 K. The characterization of NH₂C(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 ¹⁵N) and quantum chemical calculations. Upon visible-light irradiation at 680 nm, NH₂C(O)P inserts into dihydrogen by the reformation of NH₂C(O)PH₂ with concomitant isomerization to the more stable aminophosphaketene (NH₂PCO). Additionally, the photoisomerization of NH₂C(O)PH₂ to NH₂C(OH) = PH along with decomposition by yielding hydrogen-bonded complexes HNCO···PH₃ and HPCO···NH₃ has been observed in the matrix.