Synthesis and P–P cleavage reactions of [P(X)X′]2; X-ray structures of [Co{P(X)X′}(CO)3] and P4[P(X)X′]2 [X = N(SiMe3)2, X′ = NPri2]

Abstract

Treatment of P(X)(X′)Cl with KC₈ gave the crystalline diphosphine [P(X)X′]₂ (1) which dissociated reversibly into the phosphinyl radical ˙P(X)X′ (2), a plausible intermediate in the reaction of 1 with [Cr(CO)₆], [Co(NO)(CO)₃] or P₄, yielding [Cr{P(X)X′}₂(CO)₃] (3), [Co{P(X)X′}(CO)₃] (4), or 1,4-P₄[P(X)X′]₂ (5); the P(X)X′ substituent is pyramidal at P in 5 but planar in 4 [X = N(SiMe₃)₂, X′ = NPrⁱ₂].