Synthesis, structure, and clathration ability of the microporous three-dimensional coordination polymer (3)(infinity)[{CuCN(4,4 '-bpy)}center dot 2(4,4 '-bpy)]

The respectively yellow and red coordination polymers (2)(infinity)[(CuCN)( 2)(mu-4,4'-bpy)] (1) and (3)(infinity)[{CuCN(mu-4,4'-bpy)} . 2(4,41-bpy)] ( 2) (4,4'-bpy = 4,4'-bipyridine) may be prepared by self-assembly of CuCN an d 4,4'-bpy at the appropriate molar ratio in acetonitrile solution at 100 d egrees C. In 1 infinite CuCN chains are linked by 4,4'-bpy ligands into lam ellar polymers which exhibit short Cu ... C(N) contacts of 2.41(1) Angstrom between one of the crystallographically independent copper atoms and cyani de carbon atoms of a neighbouring corrugated sheet. At a molar ratio of CuC N:4,4'-bpy below 2:3, the heteroaromatic ligands also adopt a structure-dir ecting role to afford 3, in which (2)(infinity)[(CuCN)(2)(mu-4,4'-bpy)] she ets are now joined by additional bridging 4,4'-bpy spacer molecules to prov ide a three-dimensional framework, whose nanometer-sized channels (12.76x13 .12 Angstrom) accomodate two noncoordinated 4,4'-bpy guest molecules. A DTA /TGA trace demonstrates that these can be removed in two steps at 150 and 1 76 degrees C.