Grid-type two-dimensional magnetic multinuclear metal complex: strands of ([CuII(mu-4,4'-bpy)]2+)n cross-linked by octacyanotungstate(V) ions.

Reaction of the preorganized strands of (Cu(II)(mu-4,4'-bpy))n (4,4'-bpy = 4,4'-bipyridine) with W(V)(CN)(8)(-) leads to a novel cyano-bridged Cu(II)(3)W(V)(2) complex [Cu(mu-4,4'-bpy)(DMF)(2)]Cu(mu-4,4'-bpy)(DMF)W(V)(CN)(8).2DMF. 2H(2)O 1. The structure of 1 consists of the expected 2-dimensional grid-type network which is built of infinite (Cu(II)(mu-4,4'-bpy))n chains cross-linked by octacyanotungstate units. The Cu(II)-NC-W(V)-CN-Cu(II) 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) moiety and water molecules. The distance between the adjacent Cu(3)(II)W(2)(V) chains within the layer is 11.12 A 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 Cu(II)(3)W(V)(2) 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)).