Reaction Pathways of Diplatinum Complexes Bearing a Phenylpropene‐ Derived π/σ‐Chelator with Weak/Strong σ‐Donor Neutral Ligands

Abstract

The reaction of complexes [Pt(μ-Cl)(arylolefin)] 2 with various either weak σ-donor L N,S,O ligands or strong σ-donor NHCs ligands results in [PtCl(arylolefin)(L N,S,O )] with L N,S,O in a cis position to the C=C group (series A) or [PtCl(arylolefin)(NHC)] with NHC in a trans position to the C=C group (series B), respectively. The reaction directions are decided by the nature of the reactants, and not by the reaction conditions. Analyses of NMR spectra, XRD and DFT results indicate that the formation of series B is strongly dominated by electronic properties, while steric factors direct the reaction to form series A. The chemical shifts of ethylenic protons and carbons as well as the values of 2 J PtH , 3 J PtH for the allyl protons and the 3 J PtH value for H6 in the aryl group are unambiguously different for series A and series B. In addition, one complex [Pt(μ-Cl)(EtEug)] 2 and five complexes [PtCl(arylolefin)(NHC)] have been characterized by single crystal XRD.