[CuCN.Me(3)SnCN.0.5bpy] (bpy = 4,4'-Bipyridine): A Novel Supramolecular Assembly Involving the No Longer Unusual {Cu(2)(&mgr;-CN)(2)(CN)(2)} Motif.

Reaction of K(3)[Cu(CN)(4)] with Me(3)SnCl and 4,4'-bipyridine (bpy) affords the novel ternary adduct [CuCN.Me(3)SnCN.0.5bpy], 2, as yellow, cubelike crystals. The supramolecular architecture of 2 consists, according to a single-crystal X-ray study, of remarkably porous, approximately planar sheets held together by almost perpendicular bpy pillars. Basic building blocks of the sheets are {Cu(2)(&mgr;-CN)(2)(CN)(2)} fragments whose N atoms are connected, via Me(3)Sn bridges, with the N atoms of adjacent fragments. 2 crystallizes in space group P2(1)/c with (at 20 degrees C) a = 10.035(4) Å, b = 11.980(3) Å, c = 12.425(5) Å, beta = 110.94(3) degrees, and Z = 4. The dinuclear building blocks resemble strongly those of the long known, but chemically more labile, layered coordination polymer [CuCN.NH(3)], 1. Although the lattice of 2 consists of two equivalent, ideally interpenetrating 3D frameworks, spacious, straight channels of a cross section of ca. 10 Å x 5 Å persist in this unprecedented structure. The likewise polymeric new adduct [CuCN.Me(3)SnCN.H(2)O] (3) obtained from K(3)[Cu(CN)(4)] and Me(3)SnCl in the absence of bpy may be considered as a formal precursor of 2.