Hydrogen‐Bonded Complex of the Parent Phosphinidene

Abstract The diatomic molecule PH is very reactive, and it serves as the parent compound for phosphinidenes featuring a monovalent phosphorus atom. Herein, we report the characterization and reactivity of a rare hydrogen‐bonded complex of PH. Specifically, the molecular complex between PH and HCl has been generated by photolysis of chlorophosphine (H 2 PCl) at 254 nm in a solid Ar‐matrix at 10 K. The IR spectrum of the complex HP⋅⋅⋅HCl and quantum chemical calculations at the UCCSD(T)‐F12a/haTZ level consistently prove that the phosphorus atom acts as a hydrogen bond acceptor with a binding energy ( D 0 ) of −0.6 kcal mol −1 . In line with the observed absorption at 341 nm for the binary complex, the triplet phosphinidene PH undergoes prototype H−Cl bond insertion by reformation of H 2 PCl upon photoexcitation at 365 nm. However, this hydrogen‐bonded complex is unstable in the presence of N 2 and HCl, as both molecules prefers stronger interactions with HCl than PH in the observed complexes HP⋅⋅⋅HCl⋅⋅⋅N 2 and HP⋅⋅⋅2HCl.