Raman spectroscopic study of the uranyl carbonate mineral voglite

Raman spectroscopy, complemented with infrared spectroscopy, was used to study the uranyl carbonate mineral voglite. The mineral has the formula Ca₂Cu²⁺ (UO₂)(CO₃)₃](CO₃)^?6H₂O, and bands attributed to these vibrating units are readily identified in the Raman spectrum. Symmetric stretching modes at 836 and 1094 cm^?1 are assigned to ν₁(UO₂)²⁺ and ν₁(CO₃)^2? units, respectively. The ν₃ antisymmetric stretching modes of (UO₂)²⁺ are not observed in the Raman spectrum but may be readily observed in the infrared spectrum at 898 cm^?1. The ν₃ antisymmetric stretching mode of (CO₃)^2? is observed in the Raman spectrum at 1369 cm^?1 as a low intensity band as is also the ν₃(CO₃)^2? infrared modes at 1362, 1425, 1509 and 1566 cm^?1. No ν₂(CO₃)^2? Raman bending modes are observed for voglite. The Raman band at 749 cm^?1 and the two infrared bands at 747 and 709 cm^?1 are assigned to the ν₄(CO₃)^2? bending modes. U? O bond and O? H…O bond lengths in the structure of voglite were inferred from the infrared and Raman spectra. Copyright © 2007 John Wiley & Sons, Ltd.