Nuclear magnetic resonance spectra of some phosphine complexes of platinum alkyls and aryls

Abstract

The parameters from the ¹H and ³¹P n.m.r. spectra are reported for trans-[PtMeX(Et₃P)₂](X = Cl, Br, I, NO₃, N₃, NCS, NCO, NO₂, CN), cis-[PtMeX(Et₃P)₂](X = Cl, Br, N₃, NCS, Me), and some related complexes. The platinum–phosphorus coupling constant depends mainly on the covalency and s-character of the Pt–P bond, and this is used to investigate the mutual influence of the ligands in these complexes. The Pt–P bonds are weakened by the inductive effect of a methyl group in the trans-position, and it is argued that phosphines also inductively weaken bonds in the trans-position. The effects of varying the anionic ligands are similar to those produced in platinum hydrides and in methyl mercury compounds.