Heterobimetallic Cluster‐Based Coordination Polymers: Assembly, Structures and Third‐Order Nonlinear Optical Properties

Reactions of (NH4)2WS4 with CuCN, CuCN/1,2‐bis(4‐pyridyl)propane (bppa) or [Cu(MeCN)4]PF6/bppa under different reaction conditions afforded a set of two‐ or three‐dimensional W/Cu/S cluster‐based coordination polymers including {[Et4N]2[WS4Cu4(μ‐CN)2(μ‐I)2]}n (1), [WS4Cu4(μ‐CN)2(bppa)2]n (2) and {[WS4Cu4(bppa)4](PF6)2}n (3), respectively. Compound 2 can be readily formed from reaction of 1 with bppa under solvothermal conditions. Compounds 1 and 2 feature two‐dimensional networks with a “sql” topology, while 3 possesses a two‐fold interpenetrated three‐dimensional net with a rare “reo” topology. Compounds 1–3 in DMF exhibited different third‐order nonlinear optical responses, and they all showed a reverse saturable absorption while 2 held a strong self‐focusing effect. Assembly from reactions of (NH4)2WS4 with CuCN, CuCN/bppa or [Cu(MeCN)4PF6]/bppa afforded 2D and 3D cluster‐based coordination polymers with interesting structures and third‐order nonlinear optical properties.