Formation of (σ-Alkenyl)- and (μ-Vinylidene)palladium and -platinum Complexes by Oxidative Addition of 4,4-Dichloro-1,1-diphenyl-2-azabuta-1,3-diene − The Molecular Structure of an Unusual Asymmetric (μ-Vinylidene)Pd−Pd Complex

✍ Scribed by Michael Knorr; Gérard Schmitt; Marek M. Kubicki; Estelle Vigier

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 128 KB
• Volume: 2003
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200390073

✦ Synopsis

Abstract

4,4‐Dichloro‐1,1‐diphenyl‐2‐azabuta‐1,3‐diene (1) oxidatively adds to [Pd(PPh~3~)~4~] and [Pt(C~2~H~4~)(PPh~3~)~2~] giving rise to the σ‐alkenyl complexes trans‐[MCl{[C(Cl)=C(H)−N=CPh~2~]}(PPh~3~)~2~] (2a: M = Pd; 2b: M = Pt). When 1 is treated with [Pd(PPh~3~)~4~] in a 1:2 ratio in refluxing toluene, the dimetallic μ‐vinylidene complex [(PPh~3~)ClPd{μ‐[C=C(H)−N=CPh~2~]}PdCl(PPh~3~)~2~] (3) is formed. In this fluxional compound, a PPh~3~ ligands migrates in a reversible manner between the two Pd centers. Substitution of the PPh~3~ ligands of 3 by 2 equiv. of Ph~2~PCH~2~PPh~2~ affords the A‐frame complex [ClPd(μ‐dppm)~2~{μ‐[C=C(H)−N=CPh~2~]}PdCl] (4). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)