Raman spectroscopy of uranopilite of different origin - implications for molecular structure
Frost, Ray L., Cejka, Jiri, Weier, Matt L., Martens, Wayde N., & Ayoko, Godwin A. (2007) Raman spectroscopy of uranopilite of different origin - implications for molecular structure. Journal of Raman Spectroscopy, 38(4), pp. 398-409.
Uranopilite, [(UO2)6(SO4)O2(OH)6(H2O)6](H2O)8, the composition of which may vary, can be understood as a complex hydrated uranyl oxy hydroxy sulfate. The structure of uranopilite of different localities has been studied by Raman spectroscopy at 298 and 77 K. A single intense band at 1009 cm-1 assigned to the ￮1 (SO4)2- symmetric stretching mode shifts to higher wavenumbers at 77 K. Three low intensity bands are observed at 1143, 1117 and 1097 cm-1. These bands are attributed to the (SO4)2- ν3 antisymmetric stretching modes. Multiple bands provide evidence that the symmetry of the sulphate anion in the uranopilite structure is lowered. Three bands are observed at 843 to 816 cm-1 in both 298 and 77 K spectra and are attributed to the ν1 symmetric stretching modes of the (UO2)2+ units. Multiple bands prove the symmetry reduction of the UO2 ion. Multiple OH stretching modes prove a complex arrangement of OH groupings and hydrogen bonding in the crystal structure. A series of infrared bands not observed in the Raman spectra are found at 1559, 1540, 1526 and 1511 cm-1 attributed to ￤ UOH bending modes. U-O bond lengths in uranyl and O-H…O bond lengths are calculated and compared with X-ray single crystal structure analysis. Raman spectra of uranopilites of different origin show subtle differences in spectra proving the spectra are origin and sample dependent. Hydrogen-bonding network and its arrangement in the crystal structure play an important role in the origin and stability of uranopilite.
Citation countsare sourced monthly fromand citation databases.
These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.
Citations counts from theindexing service can be viewed at the linked Google Scholar™ search.
Full-text downloadsdisplays the total number of times this work’s files (e.g., a PDF) have been downloaded from QUT ePrints as well as the number of downloads in the previous 365 days. The count includes downloads for all files if a work has more than one.
Repository Staff Only: item control page