Dimethyl Compounds of Platinum(II). 1. Oxidative Addition Reactions Involving Group IV Element-Halogen Bonds

Abstract

Reactions of PtMe2(N-N) (N-N = 2,2′-bipyridine, 1, 10-phenanthroline, 2, 9-dimethyl-4,7-diphenyl-1,10-phenanthroline) with methyltin- or aryltin-halogen compounds SnRnCl4-n (R = Me, Ph; = 0-3), lead diphenyl dichloride, PbPh2Cl2, and lead triphenyl chloride, PbPh3Cl, proceeded via an oxidative addition involving the Sn-Cl or Pb-Cl bond to give the new compounds PtMe2Cl(N-N)(SnRnCl3-n) and PtMe2Cl(N-N)(PbPhmCl3-m) (m = 1, 2) in almost quantitative yield. The compounds and their reactions were studied by 1H NMR spectroscopy. Exchange reactions of PtMe2Cl(bpy)(SnRnCl3-n) with SnR′mCl4-m and reactions with Mel showed that their relative stability decreased in the order SnPhCl2 > SnMeCl2 > SnPh2Cl > SnMe2Cl > SnPh3 > SnMe3. With Mel no reaction was observed, PtMe3Cl(bpy) was formed, or PtMe3I(bpy) depending upon the stability of the platinum-tin bond. In contrast with the SnRnCl4-n compounds themselves, the platinum-tin compounds were not affected by Lewis bases such as H2O, ROH, pyridine, and PPh3. Although there was evidence that the platinum-lead bonds were stronger than the corresponding tin bonds, the former compounds decomposed in CH2Cl2 solution except PtMe2Cl(Ph2Me2phen)(PbPh2Cl), which was stable. In addition a halogen exchange between PtMe3Cl(bpy) and MeI was observed. © 1977, American Chemical Society. All rights reserved.