Synthesis, characterisation and study of the first luminescent platinum(II) compound with a [C,N,S]− terdentate ligand. X-ray crystal structure of [Pt{C6H4CHN(C6H42-SMe)}Cl]

The study of the reactions of the thioimine C6H5CHN(C6H42-SMe) with cis-[PtCl2(DMSO)2] or cis-[PtCl2(PhCN)2] is reported. The results obtained from the reactions of cis-[PtCl2(DMSO)2] with the Schiff base suggest that this platinum(II) complex induces the hydrolyses of the imine. In contrast to these findings, the treatment of equimolar amounts of C6H5CHN(C6H42-SMe) and cis-[PtCl2(PhCN)2] under refluxing toluene lead to the cycloplatinated complex: [Pt{C6H4CHN(C6H42-SMe)}Cl], which is luminescent in solution at 298 K. The X-ray crystal structure of this compound reveals that the ligand acts as a [C(sp2),N,S]− ligand and has the E (anti-) conformation. The reaction of the cycloplatinated compound [Pt{C6H4CHN(C6H42-SMe)}Cl] with PPh3 is also reported. This process produces the cleavage of the PtS bond and the formation of [Pt{C6H4CHN(C6H42-SMe)}Cl(PPh3)] in which the ligand acts as a monoanionic (C,N)− bidentate group.