Transformation of Uranyl Peroxide Studtite, [(UO2)(O2)(H2O)2](H2O)2, to Soluble Nanoscale Cage Clusters

• Published in: Inorganic chemistry Vol. 58; no. 10; pp. 6781 - 6789
• Main Authors: Lobeck, Haylie L, Isner, Jordan K, Burns, Peter C
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 20.05.2019; American Chemical Society (ACS)
• Subjects: INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; NANOSCIENCE AND NANOTECHNOLOGY; RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.9b00230

The dissolution behavior of uranyl peroxide studtite, [(UO2)­(O2)­(H2O)2]­(H2O)2, was examined under a wide range of alkaline aqueous environments with and without the addition of hydrogen peroxide. In the absence of added H2O2, studtite dissolved in aqueous solutions with a tetraethylammonium hydroxide to uranium molar ratio greater than 0.5, and the resulting species in solution characterized by Raman spectroscopy and electrospray ionization mass spectrometry (ESI-MS) is the uranyl peroxide nanocluster U24, [(UO2)­(O2)­(OH)]24 24–. This is the first demonstration of the formation of uranyl peroxide nanoclusters from studtite in a solution lacking additional hydrogen peroxide. In similar systems containing added hydrogen peroxide (0.01 M – 1.0 M), studtite dissolved in solutions with a TEAOH to uranium ratio greater than 0.1, and the resulting uranyl peroxide species in solution was U28, [(UO2)­(O2)1.5]28 28–.