SYNTHESIS AND CHARACTERIZATION OF CYCLOPALLADATED AND NON-CYCLOPALLADATED COMPLEXES OF LIGANDS CONTAINING THE 1,3-BIS(THIOMETHYL)BENZENE UNIT

The reactivity of [Pd(CH3CN)(2))Cl-2] toward the ligands 1,3-bis(ethyl thiomethyl)benzene (HL(1)), 1,3-bis(benzylthiomethyl)benzene (HL(2)), 1,3-bis(phenylthiomethyl) benzene (HL(3)) and dimethyl 2,2'-[1,3-pheny lenebis(methylthio)]-dibenzoate (HL(4)) has been investigated. In all cases the reaction of the palladium(II) salt with the corresponding li gand in acetonitrile at room temperature afforded the simple non-cyclo palladated complex. Analytical and spectroscopic data of these complex es suggest that the two sulfur atoms of the ligands and two chlorine a toms coordinate simultaneously to the palladium ion defining monomeric species. Cyclopalladated complexes of ligands HL(1)-HL(4) have been o btained by refluxing their non-cyclopalladated derivatives in acetonit rile or by direct reaction of the starting materials in the same solve nt at refluxing temperature. Different reaction times have been found depending on the ligand. Cyclopalladated complexes of ligands HL(1), H L(2) and HL(4) have been characterized by X-ray diffraction methods. A ll of them display square-planar coordination around the palladium ato m provided by the rigid S2C chelating moiety of the 1,3-bis(thiomethyl )benzene unit and the chlorine atom which is located in a trans positi on with respect to the Pd-C bond. Copyright (C) 1996 Elsevier Science Ltd