Synthesis, structure and luminescent properties of a unique [WS4Cu4]-based supramolecular compound [WS4Cu4(dmpzm)2(dca)2]∞

Treatment of [Et4N]4[WS4Cu4I6] (1) with two equivalents of bis(3,5-dimethylpyrazolyl)methane (dmpzm) and two equivalents of sodium dicyanamide (dca) in DMF/MeOH afforded a polymeric cluster of [WS4Cu4(dmpzm)2(dca)2]∞ (2). Compound 2 was fully characterized by elemental analysis, IR, UV–Vis, 1H NMR, and TGA measurements. An X-ray analysis revealed that the [WS4Cu4] core of 2 works as a very distorted tetrahedral 4-connecting node that expands to form a rare 3D (6581) topology. Photoluminescent studies on 1 and 2 in the solid state at ambient temperature revealed that 2 displayed significant enhancement of luminescent properties relative to its discrete parent cluster 1.