2–H 2O (X?=?Cl ?, Br ?, I ?) at 25?°C]]>

摘要

AbstractThe crystallization in the systems glycine–ZnX2–H2O (X?=?Cl?, Br?, I?) was summarised. Occurrence of both equilibrium and non-equilibrium crystallization was found for these systems. The systems include complex compounds, from which three anhydrous and four hydrate formula types were obtained. The main building units of their crystal structures were mixed electroneutral tetrahedra, isolated in the case ofxGly·ZnX2·yH2O (x?=?1, 2, 3;y?=?0, 1, 2) compounds, or connected in more complex polymer chains in the cases of Gly·ZnX2and 2Gly·3ZnI2·4H2O. These crystallization processes were explained on the basis of Pearson’s softness–hardness concept and the chemical species existing in the solutions. The study of the system glycine–ZnBr2–H2O at 25?°C showed the occurrence of equilibrium and non-equilibrium crystallization in it. Three hitherto unknown compounds were obtained, Gly·ZnBr2(monoclinic crystal system, space groupP21), 3Gly·ZnBr2(orthorhombic crystal system, space groupPna21) and 2Gly·ZnBr2·2H2O (monoclinic crystal system, space groupC2/c), and characterised by XRD, IR, Raman, and DTA methods.Graphical abstract

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