Matrix IR Spectra of the Products from F₂ ClF, and Cl₂ Reactions with Pulsed-Laser Evaporated Uranium Atoms

Pulsed Nd:YAG laser ablated uranium atoms were codeposited with F₂ and excess Ar onto a CsI window at 12 K. Infrared spectra revealed the presence of several uranium fluorides including the previously characterized UF₄, UF₅, and UF₆. Lower laser energy favored new absorptions at 400,446,496, and 561 cm⁻¹. These product absorptions increased stepwise during annealings which permitted diffusion and reaction of the fluorine. Similar studies with C1F produced the above absorptions plus a new band at 554 cm⁻¹ which is tentatively assigned to ClF₂⁻. The first bands appearing at 400 and 446 cm⁻¹ are assigned to UF and UF₂, respectively. The 496- and 561-cm⁻¹ bands are tentatively assigned to UF₃ and F₃⁻ respectively. Finally, uranium atoms were reacted with Cl₂. In addition to several absorptions due to UCl₄, a new double at 312 and 308 cm⁻¹ is assigned to UCl₂.