Four mono-/bi-nuclear palladium(II) complexes of triphenylphosphine and heterocyclic-N/NS ligands: Synthesis, structural characterization and luminescence properties

Abstract

The reactions of palladium(II) chloride, PPh 3 and heterocyclic-N/NS ligand in a mixture of CH 3CN (5 ml) and CH 3OH (5 ml) produced [PdCl 2(PPh 3)(L1)]·(CH 3CN) ( 1) (L1 = ADMT = 3-amino-5,6-dimethyl-1,2,4-triazine), [PdCl 2(PPh 3)(L2)] ( 2) (L2 = 3-CNpy = 3-cyanopyridine), [PdCl(PPh 3)(L3)] 2·(CH 3CN) ( 3), [PdCl(PPh 3) 2(HL3)]Cl ( 4) (HL3 = Hmbt = 2-mercaptobenzothiazole). The coordination geometry around the Pd atoms in these complexes is a distorted square plane. In 3, L3 acts as a bidentate ligand, bridging two metal centers, while in 4, HL3 appears as monodentate ligand with one nitrogen donor atom uncoordinated. Complexes 1– 4 are characterized by IR, luminescence, NMR and single crystal X-ray diffraction analysis. All complexes exhibit luminescence in solid state at room temperature.