Template self-assembly of cyano-bridged supramolecular complexes {[Cu(en)2][KM(CN)6]}n(M = CrIII, FeIII, CoIII)

Reaction of K3[M(CN)6] (M = CrIII, FeIII, CoIII ) with [Cu(en)2](ClO4)2 in water gives three cyanide-bridged supramolecular complexes, {[Cu(en)2][KM(CN)6]} n [M = CrIII (1), FeIII (2), CoIII (3); en = ethylenediamine], which have been characterized by elemental analysis, ICP analysis, IR spectra, TGA-DTA analysis and X-ray diffraction. Complex 1 crystallizes in the monoclinic, space group C2/c with cell dimensions a = 0.85237(12), b = 1.7014(3), c = 1.2103(2) nm, β = 98.70(2)° and Z = 4, and 2 crystallizes in the same space group with a = 0.8401(2), b = 1.6844(5) A, c = 1.1859(2) nm, β = 98.98(2)° and Z = 4. The crystal structures of 1 and 2 reveal a novel three-dimensional porous framework in which [Cu(en)2]2+ acts as a template, [M(CN)6]3− as a building block and K+ as a connecting unit.