Collect. Czech. Chem. Commun. 1983, 48, 1376-1389

The crystal and molecular structure of calcium (S,S)-ethylenediamine-N,N'-disuccinatoferrate octahydrate

František Pavelčík and Viktor Kettmann

Department of Analytical Chemistry, Pharmaceutical Faculty, Comenius University, 832 32 Bratislava


Crystals of Ca[Fe((S,S)-EDDS)]2.8 H2O are monoclinic with lattice parameters of a = 1.0284, b = 0.8403, c = 2.1273 nm, β = 116.04°. The space group is Pc, Z = 2. The structure was solved by the heavy atom method and refined by the least squares method to give R = 0.057. The crystals consist of [Fe(III) ((S,S)-EDDS)]- anions, hydrated Ca2+ cations and molecules of water of crystallization. The iron atoms are coordinated by two nitrogen atoms and four oxygen atom of the carboxyl groups of the hexadentate ligand. The coordination polyhedron of the iron atom forms a deformed octahedron. The absolute configuration of the complex is (O,C-6-13-A) for the (S,S) absolute ligand configuration.