Double-salt formation in crystal structures containing [Co(en)3]Cl3

The structures of three racemic double salts of [Co(en)3]Cl3 (en is ethane-1,2-diamine, C2H8N2), namely, bis[tris(ethane-1,2-diamine- κ 2N,N ′ )cobalt(III)] hexaaquasodium(I) heptachloride, [Co(en)3]2[Na(H2O)6]Cl7, bis[tris(ethane-1,2-diamine- κ 2N,N ′ )cobalt(III)] hexaaquapotassium(I) heptachloride, [Co(en)3]2[K(H2O)6]Cl7, and ammonium bis[tris(ethane-1,2-diamine- κ 2N,N ′ )cobalt(III)] heptachloride hexahydrate, (NH4)[Co(en)3]2Cl7 · 6H2O, have been determined, and the structural similarities with the parent compound, tris(ethane-1,2-diamine- κ 2N,N ′ )cobalt(III) trichloride tetrahydrate, [Co(en)3]Cl3 · 4H2O, are highlighted. All four compounds crystallize in the trigonal space group P\overline{3}c1. When compared with the parent compound, the double salts show a modest increase in the unit-cell volume. The structure of the chiral derivative [ Λ -Co(en)3]2[Na(H2O)6]Cl7 has also been redetermined at cryogenic temperatures (120   K) and the disorder noted in a previous report has been accounted for.

Source: Acta Crystallographica Section C - April 5, 2023 Category: Chemistry Authors: Kollitz, M.R. Lappin, A.G. Oliver, A.G. Tags: double salt sodium potassium ammonium ethane-1,2-diamine unit-cell volume crystal structure research papers Source Type: research