Transition metal–carbon bonds. Part XXXVI. Internal metallations of platinum–dimethyl(1-naphthyl)phosphine and –dimethyl(1-naphthyl)arsine complexes and attempts to effect similar reactions with palladium

Abstract

A number of complexes of the types [MX₂{EMe₂(1-naphthyl)}₂](M = Pt or Pd; X = Cl, I, or Me; E = P or As, are described). The platinum halide complexes showed no tendency to undergo internal metallation reactions even on prolonged heating but the methyl analogues (X = Me) readily evolved methane on pyrolysis to give complexes in which the naphthyl group had been metallated in the 8-(peri-) position. In the presence of sodium acetate, however, the platinum halide complexes readily give metallated derivatives, e.g. cis- or trans-[PtCl₂L₂](L = PMe₂C₁₀H₇) gives [PtCl(P–C)L] where (P–C) the peri-metallated phosphine (L). We were unable to metallate the palladium complexes, either decomposition occurred or starting material was recovered. ¹H N.m.r. data are given. The resonances of protons at positions 2 and 3 for complexes of types cis-[MX₂(EMe₂C₁₀H₇)₂] absorb at abnormally high τ-values (3–4); an explanation for which is given.