Low temperature chlorination and bromination of UF4 in argon matrices

Probing the electronic structures of low oxidation-state uranium fluoride molecules UFx− (x = 2−4)

“…6 The UF 5 molecule, which has C 4v symmetry, has also been well characterized. [5][6][7][31][32][33][34][35] Uranium tetrafluoride (UF 4 ) is a stable compound, in which U has an oxidation of U 4+ (5f 2 ). The UF 4 molecule in the gas phase has T d symmetry with a bond length of 2.056 ± 0.001 Å.…”

Matrix Infrared Study on the Fluorination and Chlorination of UCl4

“…Earlier matrix isolation infrared studies [1,2] on the UF 4 reaction with F 2 and Cl 2 have observed several U -F modes for UF 5 , UF 4 C1, and UF 4 C1 2 . Similarly, UF5CI along with excess UF 6 has been isolated in various matrices and characterized using infrared spectroscopy [3].…”

“…In addition, the solid inert gas matrices significantly reduce the potential of overlapping absorptions which hampered the IR study [4] on the uranium halides in liquid Xe. Like the earlier studies on the UF 4 reactions [1,2], the purpose of this matrix IR study is to characterize the uranium (V and VI) halides due to halogenation reactions, but this time the fluorination and chlorination have been approached with the UC1 4 reactant. The first IR spectra of UC1 4 F and UCI5 will be described below.…”

Mass Spectrometric Identification of Gaseous Uranium(IV) Fluoride Chlorides: UF3Cl(g) and UF2Cl2(g)

“…Recent investigations of uranium mixed halides [16][17][18][19] have focused on the low-temperature (below -60° C) synthesis and spectroscopic characterization of uranium(V) and uranium(VI) fluoride chlorides. The UF"C1^" (n = 1-5) compounds were prepared in low-temperature inert solvents or matrices by partial chlorine-exchange of UF 6 [17,18] and by fluorination of UC1 4 [19].…”

“…Although these uranium(VI) mixed halide compounds were found to be unstable above -60° C, a mass spectrum for UF 5 Cl(g) was reported [18]. The compound UF 4 C1 was obtained in a solid argon matrix at 12 Κ from the reaction of UF 4 with Cl 2 [16], and UFC1 4 was prepared by the reaction of UC1 4 with F 2 [19]. Whereas UF"C1 4 _" materials were previously characterized as bulk solid solution phases, the U(V) and U(VI) fluoride chlorides were prepared and isolated as discrete molecular species in a condensed matrix/solvent.…”