Species Distribution and Coordination of Uranyl Chloro Complexes in Acetonitrile

Autor:	Luc Van Meervelt, Christoph Hennig, Rik Van Deun, Linda Fluyt, Johan Wouters, Peter Nockemann, Christiane Görller-Walrand, Kristof Van Hecke, Kelly Servaes
Rok vydání:	2008
Předmět:	Inorganic Chemistry Crystallography chemistry.chemical_compound Aqueous solution Coordination sphere Extended X-ray absorption fine structure Chemistry Crystal structure Physical and Theoretical Chemistry Absorption (chemistry) Uranyl Acetonitrile Monoclinic crystal system
Zdroj:	Inorganic Chemistry. 47:2987-2993
ISSN:	1520-510X 0020-1669
DOI:	10.1021/ic7014435
Popis:	The complex formation of the uranyl ion, UO2 2+, with chloride ions in acetonitrile has been investigated by factor analysis of UV-vis absorption and U L3 edge EXAFS (extended X-ray absorption fine structure) spectra. As a function of increasing [Cl-]/[UO 2 2+] ratio, the five monomeric species [UO 2(H2O)5]2+, [UO2Cl(H 2O)2(MeCN)2]+, [UO 2Cl2(H2O)(MeCN)2], [UO 2Cl3(MeCN)2]-, and [UO 2Cl4]2- have been observed. The distances determined in the first coordination sphere are: U-Oax = 1.77 Å, U-OH2O = 2.43 Å, U-NMeCN = 2.53 Å, and U-Cl = 2.68 Å. A crystalline material has been obtained from the intermediate solution with the [Cl-]/[UO2 2+] ratio of ∼2, where [UO2Cl2(H2O)(MeCN) 2] is the dominating species. The crystal structure analysis of this material revealed a tetrameric complex, [(UO2) 4(μ2-Cl)4(μ3-O) 2(H2O)2(CH3CN)4] ·(CH3CN). The crystal data are: monoclinic, space group P21/n, a = 10.6388(5) Å, b = 14.8441(5) Å, c = 10.8521(5) Å, β = 109.164(5)°, and Z = 2. The U(VI) coordination of the solution species [UO2Cl2(H2O)(MeCN) 2] changes during the crystallization by replacing one MeCN molecule with a bridging μ3-O atom in the tetramer.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::83b40e54dd558daf3ce5a8b487e21478 https://doi.org/10.1021/ic7014435 Zobrazit plný text záznamu