Structural Transitions during Thermal Destruction in Family of Zinc Fluoridozirconate Crystal Hydrates

The structure of ZnZrF₆·6H₂O and ZnZrF₆·5H₂O (high- and low-temperature forms) crystal hydrates and products of their thermal destruction ZnZrF₆·4H₂O, ZnZrF₆·2H₂O, ZnZrF₆, and ZnZr₂F₁₀·2H₂O have been studied. With the exception of ZnZr₂F₁₀·2H₂O, compounds of ZnZrF₆·nH₂O (n = 6, 5, 4, 2, 0) are isostructural to their formula analogs NiZrF₆·6H₂O, α- and β-MgZrF₆·5H₂O, CuZrF₆·4H₂O, MgZrF₆·2H₂O, and MgZrF₆, respectively. The structure of ZnZr₂F₁₀·2H₂O is built of unique infinite network anionic layers \(_{\infty }^{2}\)[Zr₂F₁₀]^2–, in which ZrF₈ square antiprisms are formed tetranuclear cycles and are shared six of their vertices with four neighboring Zr-polyhedra according to the law “…–edge–edge–vertex–vertex–…”; ZnF₄(H₂O)₂-octahedra link Zr-layers to each other into a framework.