Studies of matrix isolated uranium tetrafluoride and its interactions with frozen gases

Abstract

The infrared spectra of UF4 were recorded in matrices of neon, argon, krypton, xenon, oxygen, nitrogen, nitric oxide, and carbon monoxide. These data support a tetrahedral structure for UF4 in the gas phase. Nitrogen and carbon monoxide doped argon matrices were studied as well as a fluorine doped nitrogen matrix.

Characterizing the solid hydrolysis product, UF4(H2O)2.5, generated from neat water reactions with UF4 at room temperature

“…37 For IR, the absence of resonance absorption is also consistent with anhydrous UF4 since this compound has no active vibrational modes in the IR spectral range. 38,39 Baseline characterization of anhydrous UF4 was then measured using 19 F NMR (Figure 1). Paramagnetic U 4+ causes the 19 F spin-lattice relaxation time, T1, to be very short, thus permitting a delay of only 4 ms between scans and quick acquisition of spectra with good signal-to-noise.…”

A relativistic density functional study of gaseous uranium tetrahalides

“…Also the infrared spectra of UF 4 were measured by Kunze et al [13,14] and Bukhmarina et al [15][16][17]. They observed a large number of absorption bands in the far-infrared at about 101 cm À1 and the stretching region at about 540 cm À1 .…”

“…The uranium tetrahalides play important roles in nuclear fuel enrichment and reprocessing [1], which have been studied in detail both in the solid state [2] and the gas phase [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. The first experimental electron diffraction studies of the uranium tetrahalides date from 1958 and were interpreted as regular tetrahedral geometries [3].…”

Lanthanides and Actinides

“…Upon complexation of CO to UF 4 , a shift in v c=0 to higher frequency (-»2182 cm -1 ) was observed. 60 An interaction of CO consisting primarily of σ-electron donation can be expected to show this type of behavior. Thus removal of electrons from the slightly antibonding 5σ orbital has the effect of increasing the bond strength and hence the frequency.…”