Synthesis and studies of magnesium hexafluorozirconates MgZrF6 · nH2O (n = 5, 2, 0)
摘要:
Crystalline magnesium hexafluorozirconate MgZrF6 center dot 5H(2)O isostructural to MnZrF6 center dot 5H(2)O, and having a chain-like structure, was synthesized and studied. According to thermogravimetry, the compound undergoes stepwise dehydration in the temperature range of 50-420 degrees C to give the stable phase MgZrF6 center dot 2H(2)O and the final product MgZrF6 isostructural to the cubic modification of MZrF6 (M = Cu, Fe). The vibrational spectra of the initial compound and the dehydration products are analyzed and the structures of the compounds are considered.
Effects of coordination environment on the Zr–F symmetric stretching frequency of fluorozirconate glasses, crystals, and melts
作者:Carol C. Phifer、David J. Gosztola、John Kieffer、C. Austen Angell
DOI:10.1063/1.459766
日期:1991.3
A treatment based on Badger’s rule is used to estimate symmetric stretching frequencies νs of the nonbridging fluorides of various ZrFn groups in the presence of divalent and monovalent countercations. New vibrational spectra of MgZrF6, Ba2ZrF8, and β-BaZr2F10 are presented and incorporated into the method. The factors affecting νs are outlined and discussed in detail. Compilations of estimated frequencies are used to deduce the probable local structure around Zr ions in binary barium fluorozirconate glasses and in fluorozirconate melts containing lithium and sodium ions. It is concluded that the results of Raman spectroscopy indicate the presence of seven- and eight-coordinate Zr in some barium fluorozirconate glasses.