Syntheses, crystal structures and photophysical properties of d10 transition-metal (Ag+, Cu+, Cd2+ and Zn2+) coordination complexes based on a thiophene-containing heterocyclic thioamide

Four d(10) transition-metal coordination complexes 1-4 (1: [Ag-2(TPT)(2)(TPTH)(2)]; 2: [Cu-6(TPT)(6)]2DMF; 3: [Cd(TPT)(2)(TPTH)]CH3CH2OH, 4: [Zn(TPT)(2)](n)) have been constructed from a newly designed heterocyclic thioamide ligand, TPTH (TPTH=4-(thiophen-2-yl)-pyrimidine-2-thiol). All complexes have been structurally elucidated by single crystal X-ray diffraction analyses. Except for 4, which shows a one-dimensional (1-D) chain structure, 1-3 are all discrete coordination complexes featuring dinuclear, hexanuclear and mononuclear entities, respectively. Their photophysical properties have been evaluated in the solid state at room temperature by UV-vis diffuse reflectance and luminescence spectra. Among them, 2 exhibits a strong red luminescence ((em)=699nm) with a remarkable red-shift of the maximum emission compared to that of the TPTH ligand ((em)=536nm). The red emission observed with 2 is ascribed to a LMCT (ligand-to-metal charge transfer) transition which agrees with the DFT calculations. [GRAPHICS]