Structures and Photoluminescence Properties of Two Cu(I) Thiolate Complexes Supported by Sulfur-Sulfur Interactions

Two novel Cu(I) complexes, [Cu(tdt)] (1) and [Cu₆(mtt)₆] (2), were synthesized using the solvothermal method with CuI and 1,3,4-thiadiazole-2-thiol (Htdt) or 4-methylthiazole-2-thiol (Hmtt). In 1, Cu(I) coordinates with the tdt ligand to form a new two-dimensional copper-sulfur based coordination polymer; tdt links binuclear copper clusters into a graphite-like layered structure. In 2, Cu(I) coordinates with the mtt ligand to form a copper-sulfur cluster-based compound; six mtt surround six copper atoms to construct an inverted triangular prismatic [Cu₆S₆] cluster molecule. Sulfur-sulfur interactions were observed in the structures of both compounds. We also tested the luminescent properties of the compounds: complex 1 emits red light at 632 nm under excitation, while complex 2 emits near-infrared photoluminescence at 833 nm in its solid-state photoluminescence spectrum.