Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

Infrared spectra of mineral possessing layer structure - liebigite, Ca₂[UO₂(CO₃)₃].(8-11) H₂O, schroeckingerite, NaCa₃[UO₂(CO₃)₃]SO₄F.10 H₂O, voglite, Ca₂Cu[UO₂(CO₃)₄].6 H₂O (?), and synthetic andersonite, Na₂Ca[UO₂(CO₃)₃].6 H₂O - were measured and interpreted and compared with the published infrared spectra of ammonium, potassium, rubidium, and cesium dioxo-tricarbonatouranates(VI). From the analysis of the infrared spectra it follows - in accordance with the results of X-ray diffraction analysis - that in the dioxo-tricarbonatouranate(VI) complex anion, [UO₂(CO₃)₃]^4-, forming hexagonal bipyramid, three bidentately bonded carbonate groups are present in the equatorial plane (in liebigite and andersonite and apparently also in schroeckingerite and voglite). The coordinations of the SO₄^2- and F^- ions in schroeckingerite and of the fourth carbonate group (?) in voglite have not been elucidated.