Metal‐Free Activation of Hydrogen, Carbon Dioxide, and Ammonia by the Open‐Shell Singlet Biradicaloid [P(μ‐NTer)] 2

The Group 15 open‐shell singlet biradicaloid [P(μ‐NTer)] 2 (Ter=2,6‐bis(2,4,6‐trimethylphenyl)phenyl) was utilized in the activation of stable small molecules. Fast reactions with H 2 , CO 2 , and NH 3 were observed. Dihydrogen easily added to [P(μ‐NTer)] 2  , yielding [HP(μ‐NTer)] 2 under ambient conditions whereas reversible release of molecular hydrogen was observed at slightly elevated temperatures ( T >60 °C). As [P(μ‐NTer)] 2 is a species with phosphorus in the unusual formal oxidation state +II, it is capable of reducing carbon dioxide to afford a zwitterionic compound, [OP(μ‐NTer) 2 P], and carbon monoxide. The reaction of [P(μ‐NTer)] 2 with ammonia led to the formation of an azadiphosphiridine after rearrangements of the central P 2 N 2 heterocycle.