Double-salt formation in crystal structures containing [Co(en)]Cl.

The structures of three racemic double salts of [Co(en)]Cl (en is ethane-1,2-diamine, CHN), namely, bis[tris(ethane-1,2-diamine-κN,N')cobalt(III)] hexaaquasodium(I) heptachloride, [Co(en)][Na(HO)]Cl, bis[tris(ethane-1,2-diamine-κN,N')cobalt(III)] hexaaquapotassium(I) heptachloride, [Co(en)][K(HO)]Cl, and ammonium bis[tris(ethane-1,2-diamine-κN,N')cobalt(III)] heptachloride hexahydrate, (NH)[Co(en)]Cl·6HO, have been determined, and the structural similarities with the parent compound, tris(ethane-1,2-diamine-κN,N')cobalt(III) trichloride tetrahydrate, [Co(en)]Cl·4HO, are highlighted. All four compounds crystallize in the trigonal space group P-3c1. When compared with the parent compound, the double salts show a modest increase in the unit-cell volume.

Structure of Λ(δλλ)-[Co(en)]I(I).

The structure of tris-(ethane-1,2-di-amine-κ ')cobalt(III) bis-(iodide) triiodide, [Co(CHN)]I(I), at 120 K has ortho-rhom-bic (222) symmetry. The di-amine nitro-gen atoms form N-H⋯I hydrogen bonds throughout the lattice, resulting in a three-dimensional network, which involves the iodide and all atoms in the triiodide anions.