Ethylenediamine-N,N"-Diacetate Ion (Edda2–) as a Tridentate Ligand: Synthesis and Structure of the [Co(Edda)(Dien)]ClO4 · H2O and [Co(Edda)(En)(CN)] · 2H2O Complexes

Research paper by I. M. Bezrukavnikova, T. N. Polynova, A. L. Poznyak, L. V. Stopolyanskaya

Indexed on: 01 Mar '02Published on: 01 Mar '02Published in: Russian Journal of Coordination Chemistry


The cobalt(III) complexes with tridentate ethylenediamine-N,N"-diacetate ions (Edda2–) and additional ligands, namely, diethylenetriamine (Dien) or ethylenediamine (En) and cyanide ions, were synthesized. As follows from X-ray diffraction analysis of [Co(Edda)(Dien)]ClO4· H2O (monoclinic crystals with a = 9.243 (2) Å, b = 14.167 (4) Å, c = 13.046 (3) Å, β = 91.19 (2)°, Z = 4, space group P21/c), the secondary N atom of the Dien ligand occupies the trans-position relative to the N atom of the Edda2– ligand, which contains a free acetate group. Two fac-isomers of [Co(Edda)(En)(CN)] with the CN– ion in the cis- and trans-positions relative to the oxygen atom of the carboxyl group were isolated, and the structure of the trans-(O,CN)-[Co(Edda)(En)(CN)]· 2H2O was determined: monoclinic crystals with a = 9.136 (3) Å, b = 15.484 (3) Å, c = 10.564 (3) Å, β = 110.67 (5)°, Z = 4, space group P21/c.