Heterobimetallic Cluster-Based Coordination Polymers: Assembly, Structures And Third-Order Nonlinear Optical Properties

Reactions of (NH4)(2)WS4 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(mu-CN)(2)(mu-I)(2)]}(n) (1), [WS4Cu4(mu-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.