Notes. First synthesis and structural assessment of alkali-metal carbonatodioxoperoxouranate(VI) monohydrates, A2[UO2(O2)(CO3)]·H2O, and carbonato-oxodiperoxovanadate(V) trihydrates, A3[VO(O2)2(CO3)]·3H2O

Abstract

The complexes A₂[UO₂(O₂)(CO₃)]·H₂O (A = Na or K) have been synthesised from the reaction of the product obtained by treating UO₂(NO₃)₂·6H₂O with AOH and AHCO₃(ratio U : CO₃^2–= 1:4) with an excess of 30% H₂O₂ at pH 7–8, and A₃[VO(O₂)₂(CO₃)]·3H₂O (A = Na or K) have been synthesised by treating V₂O₅ with A₂CO₃(ratio V: CO₃^2–= 1 :1.5) and an excess of 30% H₂O₂ at pH ca. 7. They were precipitated with ethanol. The occurrence of trans OUO and terminal VO in the [UO₂(O₂)(CO₃)]^2– and [VO(O₂)₂(CO₃)]^3– ions, respectively, and the presence of triangular bidentate O₂^2– and chelated bidentate CO₃^2– groups, have been ascertained from i.r. and laser Raman spectra. The complexes A₂[UO₂(O₂)(CO₃)]·H₂O can be dehydrated at Ca. 100 °C, a temperature at which A₃[VO(O₂)₂(CO₃)]·3H₂O starts to decompose.