Water Complex of Imidogen

Imidogen (NH) is the simplest nitrogen hydride that plays an important role in combustion and interstellar chemistry, and its combination with H₂O is the prototypical amidation reaction of O-H bonds involving a nitrene intermediate. Herein, we report the observation of the elusive water complex of NH, a prereaction complex associated with the amidation reaction in a solid N₂ matrix at 10 K. The hydrogen-bonded structure of NH···OH₂ (versus HN···HOH) is confirmed via IR spectroscopy with comprehensive isotope labeling (D, ¹⁸O, and ¹⁵N) and quantum chemical calculations at the UCCSD(T)/aug-cc-pVQZ level of theory. In line with the observed absorption at 350 nm, irradiation of the complex at 365 nm leads to O-H bond insertion, yielding hydroxylamine NH₂OH.