The equilibrium crystallization of complex compounds of the type Gly路MSO
4路5H
2O with a structure derived from those of the crystallized double salts MSO
4路
xH
2O, where
x = 6, 7 was predicted and proven in the systems Gly-MSO
4-H
2O (M = Mg
2+, Mn
2+, Fe
2+, Co
2+, Ni
2+ and Zn
2+). It was predicted that stable octahedral complexes [M(H
2O)
6]
2+ and
trans-[M(H
2O)
4(O-gly)
2]
2+, as well as [SO
4]
2鈭?/sup> tetrahedra, which were the main building units of the crystallizing Gly路MSO4路5H2O compounds (triclinic crystal system, space group P 鈭?#xA0;1), were predominating in these solutions. The vibrational spectra and the thermal behavior of the Gly路MSO4路5H2O compounds (M = Mg2+, Co2+, Zn2+) are in accord with the refined crystal structures. The cobalt compound displays antiferromagnetic behavior whereas the nickel and manganese compounds are ferromagnetic.In the manganese system where MnSO4路H2O (308 K) crystallizes, the only complex compound is the anhydrous Gly路MnSO4 with a polymeric type structure .
A new compound Gly路CoSO4路3H2O was found in the cobalt system under unstable equilibrium conditions. Gly路CoSO4路3H2O was proven to consist of two types of octahedra, trans-[Co(H2O)4(O-gly)2]2+ and trans-[Co(H2O)2(SO4)2(O-gly)2]2鈭?/sup>, forming a chain structure (monoclinic crystal system, space group P21/c).