Synthesis and structure determination of racemic (Δ/Λ)-tris(ethylenediamine)cobalt(III) trichloride hemi(hexaaquasodium chloride)

Abstract

The synthesis and crystal structure of the title racemic compound, [Co(C2H8N2)3]Cl3.{[Na(H2O)6]Cl}0.5, are reported. The trivalent cobalt atom, which resides on a crystallographic threefold axis, is chelated by a single ethylene diamine (en) ligand and yields the tris-chelate [Co(en)3]3+ cation with distorted octahedral geometry after the application of crystal symmetry. The sodium cation (site symmetry \overline{3}), has a single water molecule bound to it in the asymmetric unit and yields a distorted, octahedrally coordinated hydrated [Na(H2O)6]+ cation after the application of symmetry. One of the chloride ions lies on a general position and the other has \overline{3} site symmetry. An extensive array of C—H...O, N—H...Cl and O—H...Cl hydrogen bonds exists between the ethylene diamine ligands, the water molecules of hydration, and the anions present, thereby furnishing solid-state stability.