Complexes with a Monohapto Bound Phosphorus Tetrahedron and Phosphaalkyne1

The reaction of white phosphorus with the coordinatively unsaturated [M(CO) 3 (PR 3 ) 2 ] complexes (M = Mo, W; R = Cy, Pr i ) yields the compounds [M(CO) 3 (PR 3 ) 2 (η 1 -P 4 )] in which the P 4 -tetrahedron is end-on bonded to the metal. In the same manner reacts Ar‘C⋮P (Ar‘ = C 6 H 2 Bu t 3 -2,4,6) with this complex to give [W(CO) 3 (PCy 3 ) 2 (η 1 -P⋮CAr‘)]. The X-ray structures of the products are discussed, and for the P 4 -unit in [W(CO) 3 (PCy 3 ) 2 (η 1 -P 4 )] the librational analysis was performed to correct their translational and rotational motions.