MATRIX IR-SPECTRA OF THE PRODUCTS FROM F2, CIF, AND CL-2 REACTIONS WITH PULSED-LASER EVAPORATED URANIUM ATOMS

Pulsed Nd:YAG laser ablated uranium atoms were codeposited with F-2 an d excess Ar onto a CsI window at 12 K. Infrared spectra revealed the p resence of several uranium fluorides including the previously characte rized UF4, UF5, and UF6. Lower laser energy favored new:absorptions at 400, 446, 496, and 561 cm(-1). These product absorptions increased st epwise during annealings which permitted diffusion and reaction of the fluorine. Similar studies with ClF produced the above absorptions plu s 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 UF 2, respectively. The 496- and 561-cm(-1) bands are tentatively assigne d to UF3 and F-3(-) respectively. Finally, uranium atoms were reacted with Cl-2. In addition to several absorptions due to UCl4, a new doubl et at 312 and 308 cm(-1) is assigned to UCl2.