ArticleStructural and energetic studies on double salts of M(II)Mg2Cl6·12H2O (M  Ca, Mn, Cd) by X-ray diffraction and density functional methods
Review articleOpen access
Abstract:

AbstractThe crystal structure of the double salt complex MnMg2Cl6·12H2O has been determined by a single crystal X-ray diffraction method. The phase is trigonal, space group P31c, with unit cell dimensions a = 9.953(3) and c = 11.467(3) Å. The crystal structure consists of two kinds of well-separated octahedra, [Mg(H2O)6]2+ and [MnCl6]4−, which is isomorphous with the CdMg2Cl6·12H2O crystal. In order to examine the stability of the double salt crystals, full geometry optimizations have been carried out for several octahedral polyhedra of [M(H2O)6]2+ and [MCl6]4− (MMg2+, Ca2+, Mn2+, Cd2+) by the ab initio density functional method. Comparison of formation energies (ΔE) for [Mg(H2O)6]2+, [M(II)(H2O)6]2+, [MgCl6]4− and [M(II)Cl6]4− independently optimized {(ΔE([Mg(H2O)6]2+) + ΔE([M(II)Cl6]4−)) versus (ΔE([MgCl6]4−) + ΔE([M(II)(H2O6]2+)); M  Ca, Mn, Cd}, reveal that the former combination of polyhedra is significantly stable in comparison with the latter, indicating that the formation energies of the first coordination spheres play a decisive role in determining the constituent polyhedra of the double salt crystals.

Request full text

References (0)

Cited By (0)

No reference data.
No citation data.
Advertisement
Join Copernicus Academic and get access to over 12 million papers authored by 7+ million academics.
Join for free!