Reaction of halide ion with [Cr(CO)2(η-C6Me6)(NO)][PF6]: stabilisation of the product by phosphine substitution and X-ray crystal structure of trans, trans-[Cr(I)(CO)2(PPh2Me)2(NO)]

Abstract

Addition of halide ion, X-, to [Cr(CO)₂(η-C₆Me₆)(NO)][PF₆] afords red solutions from which, on addition of phosphorus donor ligands, L, may be isolated [Cr(X)(CO)₂(L)₂(NO)]. The identities of two carbonylnitrosyl species present in the intermediate red solutions are discussed with reference to the crystal structure of trans,trans-[Cr(I)(CO)₂(PPh₂Me)(NO)]; crystals are monoclinic, space group P2₁, with Z= 2 in a unit cell of dimensions a= 9.796(4), b= 18.019(8), c= 8.968(1)Å, β= 116.96(3)°. The structure was solved from diffractometer data by the heavy-atom method, and refined to R 0.005 for 2.233 observed reflections.