Preparative and proton and phosphorus-31 nuclear magnetic resonance studies on palladium(II) complexes with t-butylphosphines

Abstract

Some new complexes of the types [PdX₂(PBu^tR₂)₂],[PdX₂(PBu^t₂R)₂] and [Pd₂X₄(PBu^t₂Ph)₂](X = Cl, Br, or l; R = Me, Et, Prⁿ, Buⁿ, Ph, or p-tolyl) are described. Many of the complexes have mutually trans, phosphine ligands, as shown by the t-butyl ¹H n.m.r. pattern. ³¹P N.m.r. data for these and other palladium–tertiary phosphine complexes are given. There is a linear correlation between the chemical shift of the free phosphine, δ, and the coordination shift, Δ, on complexation, i.e., for trans-[PdCl₂L₂], Δ=–(28·01 ± 0·61)–(0·359 ± 0·023)δ and for cis-[PdCl₂L₂], Δ=–(38·11 ± 0·86)–(0·315 ± 0·033)δ. Other ¹H n.m.r. and i.r. data are given.