Carbamoylphosphinidene: A Phosphorus Analogue of Carbonyl Nitrene

Abstract

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 NH 2 C(O)P, which was generated through the photolytic (193 nm) dehydrogenation of phosphinecarboxamide (NH 2 C(O)PH 2 ) in a solid N 2 -matrix at 12 K. The characterization of NH 2 C(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 15 N) and quantum chemical calculations. Upon visible-light irradiation at 680 nm, NH 2 C(O)P inserts into dihydrogen by the reformation of NH 2 C(O)PH 2 with concomitant isomerization to the more stable aminophosphaketene (NH 2 PCO). Additionally, the photoisomerization of NH 2 C(O)PH 2 to NH 2 C(OH) = PH along with decomposition by yielding hydrogen-bonded complexes HNCO•••PH 3 and HPCO•••NH 3 has been observed in the matrix.