Synthesis and photophysical properties of isocyano Ruthenium(II) quinoline-8-thiolate complexes with visible-light and near-infrared emission

The reactions of [RuII(SQ)2(PPh3)2] (SQ = quinoline-8-thiolate) with different isocyanide ligands affords a series of emissive bis(quinoline-8-thiolate) ruthenium(II) complexes [RuII(SQ)2(PPh3)(CNR)] (1–6). Two isomeric forms, i.e. cis,trans (1a – 6a) and cis,cis (1b – 6b) have been separated in these reactions. With the variation on the π-accepting ability of the isocyanide ligands, the CN stretches, lowest energy absorptions and the photoluminescence can be systematically modified.