On the Crystal Structure of a Tetranuclear Hydroxo Complex of Uranyl(VI).

An Energy Dispersive X‐ray Diffraction Study of Dioxouranium(VI) in 1 M Lithium Citrate

“…The bond lengths, and their spatial disposition are in good agreement with the literature data: dioxouranium(), in solution and in the solid state, is coordinated with five neighbors; the uranium atoms are at the centers of neighboring pentagonal bipyramids. [14] The large peak at about 3.95Å indicates that the five O atoms, positioned on the equatorial plane of the pentagonal bipyramid, do not belong to the citric anions present in solution. The contributions of the five C atoms, bound to the O atoms, are altogether inadequate to fit the experimental peak.…”

Crystal growth, structural characterization, cation–cation interaction classification, and optical properties of uranium(vi) containing oxychlorides, A4U5O16Cl2 (A = K, Rb), Cs5U7O22Cl3, and AUO3Cl (A = Rb, Cs)

“…Uranium oxychlorides have been synthesized by several different methods, including precipitation from lowtemperature solutions, solid state processing, and flux crystal growth. The majority of the compositions were made from low-temperature solutions with high chloride concentrations, 19,21,[34][35][36] however, like all methods, this approach has limitations and it will not crystallize structures where high temperatures are needed to overcome thermal barriers. The flux growth technique, on the other hand, has proven very effective for the discovery of new complex oxide materials, 37 and the use of chloride fluxes for the growth of uranium containing oxides and oxychlorides has been reported previously, 5,17,28,38 suggesting great promise for discovery of novel oxychlorides.…”

Structure cristalline et moléculaire du complexe tétranucléaire K2(UO2)4O2-(OH)2Cl4(H2O)6

“…Ces 6carts sont dfis, pour l'essentiel, ~ des interactions 61ectrostatiques. En effet, les quatre coordinats polaris6s n+gative-ment, qui entourent l'uranium U(2), doivent repousser les oxyg6nes uranyles O (201) R&~rences: (1) ~tudes structurales: (a) Aberg (1969), (b) Perrin (1976b), (c) Jamet, Dao & Morlaes (1975), (d) Aberg (1971), (e) ce travail, (f) Perrin (1977); (2) &udes vibrationnelles: (g) Perrin & C aillet (1976), (h) Perrin & Prigent (1975), (i) K nidiri (1975, (j') Perrin & Prigent (1977).…”