Platinum complexes of dibenzo[1,2]dithiin, dibenzo[1,2]dithiin oxides and related polyaromatic hydrocarbon ligands

The synthesis of platinum bisphosphine complexes of biphenyl-2,2'-dichalcogenates and the oxides of dibenzo[1,2]dithiin and related ligand systems by oxidative addition to [Pt-(PPh3)(4)] is reported. We also describe the synthesis of a new compound, di-benzothiophen-4-yldiselenide and its simple platinum complex (obtained by oxidative addition). All complexes have been fully characterised, principally by using multinuclear NMR spectroscopy and in six cases by means of single-crystal X-ray diffraction studies. The majority are simple S/S or Se/Se complexes, however the addition of dibenzo[1,2]dithin trioxide to [Pt(PPh3)(4)] gives a bimetallic system, [Pt-[2-[S(O)],2'[S(O)(2)]-biphen](PPh3)](2), containing a central Pt2S2O2 core in which the ligand behaves as a tridentate S,S,O donor.