@article {Bezrukavnikova:2002:1070-3284:212, author = "Bezrukavnikova I.M. and Polynova T.N. and Poznyak A.L. and Stopolyanskaya L.V.", title = "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", journal = "Russian Journal of Coordination Chemistry", volume = "28", number = "3", year = "2002", abstract = "
The cobalt(III) complexes with tridentate ethylenediamine-N,N"-diacetate ions (Edda^2–) 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)]ClO_4 · H_2O (monoclinic crystals with a = 9.243 (2) Å, b = 14.167 (4) Å, c = 13.046 (3) Å,
= 91.19 (2)°, Z = 4, space group P2_1/c), the secondary N atom of the Dien ligand occupies the trans-position relative to the N atom of the Edda^2– 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)]_ · 2H_2O was determined: monoclinic crystals with a = 9.136 (3) Å, b = 15.484 (3) Å, c = 10.564 (3) Å,
= 110.67 (5)°, Z = 4, space group P2_1/c.