Synthesis andmolecular geometry of [trans-PtCl2PBu3]2 (di-t-Bu-diimine) containing a s,s-N,N' bridging diimine with a planar anti-(trans-P-Pt-NCCN-Pt-P-trans)-skeleton

Abstract

Complexes of the type [MCl{2}XR'{3}]{2}R-dim (M = Pd or Pt; XR'{3} = arsine or phosphine) are formed in almost quantitative yield in the reactions of [MCl{2}XR'{3}]{2} with @a-diimine (11 molar ratio Pt-dimer/R-dim). An X-ray study of [PtCl{2}PBu{3}]{2}t-Bu-dim [Z = 2, a = 11.4540(11), b = 16.1169(7), c = 12.9202(12) @9 and @b = 99.82(1); R = 5.9%] reveals a structure consisting of two planar trans-PtCl{2}P-units bridged by a planar NCCN skeleton in anti-configuration [C@?C 1.48(2), C@?N 1.27(3), N@?Pt 2.214(10) @9]. As a consequence of the orthogonal position of the platinum coordination plane and the NCCN plane the @b-imine proton resides a short distance from the platinum atom (about 2.6 @9). The structure in solution has been determined by }1{H, }1{}3{C, }3{}1{P and }1{}9{}5{Pt NMR spectroscopy. The observed spectra point to retention of the structural features in solution as evidenced by a large down field shift of the imine protons, e.g. 9.58 ppm and an AA'MM' pattern in [PdCl{2}PEt{3}]{2}t-Bu-dim. The present compounds are the first examples of complexes which contain a @s, @s'-N,N' planar bridging diimine ligand as a general structural feature.