The X-ray crystallographic study of the reaction of bis(2-thienyl) ditelluride with tetrakis(triphenylphosphine)platinum or -palladium

The oxidative addition of dithienyl ditelluride to [Pt(PPh3)(4)] in dichlor omethane results in the formation of a trinuclear complex [Pt3Te2(Th)(PPh3) (5)]Cl (Th = 2-thienyl, C4H3S) (1) as well as a mononuclear complex [PtCl(T h)(PPh3)(2)] that have been identified and structurally characterized by X- ray crystallography and P-31-NMR spectroscopy. The analogous reaction invol ving [Pd(PPh3)(4)] forms a mixture of several products. In dichloromethane [Pd6Cl2Te4(TeTh)(2)(PPh3)(6)] (2) can be isolated and its X-ray structure d etermined. In toluene [Pd6Te4(TeTh)(4)(PPh3)(6)] (3) is formed. Both 2 and 3 have a similar hexanuclear framework which has previously been reported f or [Pd6Te6(PEt3)(8)] in the literature. These products indicate that the cl eavage of both Te-Te and C-Te bonds as well as the choice of the solvent pl ay an important role in the oxidative addition. The trinuclear and hexanucl ear complexes can be considered to be formed from an initial mononuclear ad dition product. The reaction pathways are compared to those involved in the reaction of Th2Se2 and [M(PPh3)(4)] (M = Pt, Pd). (C) 2000 Elsevier Scienc e S.A. All rights reserved.