Bis(N-ethylethylenediamine-κ2 N,N′)copper(II)–hexacyanocobaltate(III)–water (3/2/4): a two-dimensional ladder structure of a bimetallic assembly

Abstract

The title compound, poly[[tetracyano-octa-μ-cyano-hexakis(N-ethylethylenediamine)tricopper(II)dicobaltate(III)] tetrahydrate], [Cu(C4H12N2)2]3[Co(CN)6]2·4H2O or {[Cu3Co2(CN)12(C4H12N2)6]·4H2O} n , was crystallized from an aqueous reaction mixture containing Cu(ClO4)2, N-ethylethylenediamine and K3[Co(CN)6] in a self-assembling process. The polymeric chains are extended through –CoIII–CN–CuII– linkages involving four or two cyanide ligands of the centrosymmetric [Co(CN)6]3− complex ions, forming a two-dimensional ladder structure. The CuII 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 in-plane 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.