Grid-Type Two-Dimensional Magnetic Multinuclear Metal Complex: Strands of {[Cu^II(μ-4,4‘-bpy)]²⁺}<i>_n</i> Cross-Linked by Octacyanotungstate(V) Ions

Reaction of the preorganized strands of {[CuII(μ-4,4‘-bpy)]2+}n (4,4‘-bpy = 4,4‘-bipyridine) with [WV(CN)8]3- leads to a novel cyano-bridged CuII3WV2 complex [Cu(μ-4,4‘-bpy)(DMF)2][Cu(μ-4,4‘-bpy)(DMF)]2[WV(CN)8]2·2DMF· 2H2O 1. The structure of 1 consists of the expected 2-dimensional grid-type network which is built of infinite {[CuII(μ-4,4‘-bpy)]2+}n chains cross-linked by octacyanotungstate units. The CuII−NC−WV−CN−CuII linkage exhibits the topology of a 3,2-chain. The skeleton of the layer is additionally stabilized by a hydrogen bond network formed by terminal cyano ligands of the [W(CN)8]3- moiety and water molecules. The distance between the adjacent Cu3IIW2V chains within the layer is 11.12 Å along the a axis. The layers are connected by H-bonds of NCN−NDMF−NCN linkages into 3-D supramolecular architecture. The magnetic properties correspond to a dominant ferromagnetic coupling within the CuII3WV2 pentamer units (J = +35(4) cm-1) and much weaker effective AF interunit coupling which include both intra- and inter-3,2-chain interactions between pentamers (J‘ = −0.05(1) cm-1).