caa a22 4500 378851349 CHVBK 20180305123324.0 cr unu---uuuuu 161128e20030901xx s 000 0 eng 10.1524/ract.91.9.525.19995 doi (NATIONALLICENCE)gruyter-10.1524/ract.91.9.525.19995 Structural characterization of a ternary Fe(III)-U(VI)-citrate complex [Elektronische Daten] [Cleveland J. Dodge, Arokiasamy J. Francis] Citric acid, a naturally occurring hydroxycarboxylic acid, forms bidentate, tridentate, dinuclear, or polymeric species, depending on the metal. In the presence of iron and uranium a ternary Fe: U: citric acid complex is formed. We determined the molecular structure of the ternary complex in both the aqueous and solid phase. Fourier transform infrared spectroscopy (FTIR) showed the presence of uni- and bi-dentate bonding of the citric acid to the metals, and the involvement of the α-hydroxyl group. Analysis of molecular fragments generated from time-of-flight secondary ion mass spectroscopy (TOF-SIMS) confirmed the bonding of terminal carboxylate groups of citric acid to uranium and iron. Extended X-ray absorption fine structure (EXAFS) analysis revealed the dinuclear nature of the Fe bonding to citrate and mononuclear uranium species with citrate. Coordination of a sodium atom to the iron was also noted. The proposed empirical formula for the complex is [NaFe2(μ-O)(μ-citrato)(OH)2(H2O)(C6H4O7)bis(UO2)(C6H5O7)]7-. The structure consists of a dinuclear ferric ion core coordinated through an oxy (μ-O) and a carboxylate (μ-citrato) group of citric acid. The mononuclear uranyl ions are coordinated in bidentate fashion to the central carboxylate groups of citric acid and tridentate coordinated to citric acid. © 2003 Oldenbourg Wissenschaftsverlag GmbH Laboratory techniques, experiments nationallicence Analytical chemistry nationallicence Inorganic chemistry nationallicence Dodge Cleveland J. aut Francis Arokiasamy J. aut Radiochimica Acta/International journal for chemical aspects of nuclear science and technology Oldenbourg Wissenschaftsverlag GmbH 91/9/2003(2003-09-01), 525-532 0033-8230 91:9/2003<525 2003 91 ract https://doi.org/10.1524/ract.91.9.525.19995 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1524/ract.91.9.525.19995 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dodge Cleveland J. aut NATIONALLICENCE 700 1- Francis Arokiasamy J. aut NATIONALLICENCE 773 0- Radiochimica Acta/International journal for chemical aspects of nuclear science and technology Oldenbourg Wissenschaftsverlag GmbH 91/9/2003(2003-09-01), 525-532 0033-8230 91:9/2003<525 2003 91 ract CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter