Bis(N-ethylethylenediamine-κ2N,N′)copper(II)-hexacyanocobaltate(III)-water (3/2/4):: a two-dimensional ladder structure of a bimetallic assembly

The title compound, poly[[tetracyano-octa-mu-cyano-hexakis-(N-ethylethylenediamine) tricopper(II)dicobaltate(III)] tetrahydrate], [Cu(C4H12N2)(2)](3)[Co(CN)(6)](2)center dot 4H(2)O or {[Cu3Co2-(CN)(12)(C4H12N2)(6)]center dot 4H(2)O}(n), was crystallized from an aqueous reaction mixture containing Cu(ClO4)(2), N-ethylethylenediamine and K-3[Co(CN)(6)] in a self-assembling process. The polymeric chains are extended through -Co-III-CN-Cu-II linkages involving four or two cyanide ligands of the centrosymmetric [Co(CN)(6)](3-) complex ions, forming a two-dimensional ladder structure. The Cu-II atoms, one of which also lies on an inversion centre, have a distorted octahedral coordination geometry, the degree of tetragonal Jahn-Teller distortion being T = 0.785 and 0.810 (T is the ratio of mean inplane Cu-N bond lengths to axial Cu-N bond lengths). This local Jahn-Teller distortion results from the anisotropic features of this two-dimensional cyano-bridged structure.