Title: | "A structural and electrochemical investigation of 1-alkyl-3-methylimidazolium salts of the nitratodioxouranate(VI) anions [[UO2(NO3)2]2(mu 4-C2O4)]2-, [UO2(NO3)3]-, and [UO2(NO3)4]2" |
Author(s): | Bradley AE; Hardacre C; Nieuwenhuyzen M; Pitner WR; Sanders D; Seddon KR; Thied RC; |
Address: | "The QUILL Centre, The School of Chemistry, Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom" |
ISSN/ISBN: | 0020-1669 (Print) 0020-1669 (Linking) |
Abstract: | "The properties of the 1-butyl-3-methylimidazolium salt of the dinuclear mu(4)-(O,O,O',O'-ethane-1,2-dioato)bis[bis(nitrato-O,O)dioxouranate(VI)] anion have been investigated using electrochemistry, single-crystal X-ray crystallography, and extended X-ray absorbance fine structure spectroscopy: the anion structures from these last two techniques are in excellent agreement with each other. Electrochemical reduction of the complex leads to the a two-electron metal-centered reduction of U(VI) to U(IV), and the production of UO(2), or a complex containing UO(2). Under normal conditions, this leads to the coating of the electrode with a passivating film. The presence of volatile organic compounds in the ionic liquids 1-alkyl-3-methylimidazolium nitrate (where the 1-alkyl chain was methyl, ethyl, propyl, butyl, pentyl, hexyl, dodecyl, hexadecyl, or octadecyl) during the oxidative dissolution of uranium(IV) oxide led to the formation of a yellow precipitate. To understand the effect of the cation upon the composition and structure of the precipitates, 1-alkyl-3-methylimidazolium salts of a number of nitratodioxouranate(VI) complexes were synthesized and then analyzed using X-ray crystallography. It was demonstrated that the length of the 1-alkyl chain played an important role, not only in the composition of the complex salt, but also in the synthesis of dinuclear anions containing the bridging mu(4)-(O,O,O',O'-ethane-1,2-dioato), or oxalato, ligand, by protecting it from further oxidation" |
Notes: | "PubMed-not-MEDLINEBradley, Antonia E Hardacre, Christopher Nieuwenhuyzen, Mark Pitner, William R Sanders, David Seddon, Kenneth R Thied, Robert C eng 2004/04/13 Inorg Chem. 2004 Apr 19; 43(8):2503-14. doi: 10.1021/ic035350b" |