Infrared spectra in the 550–410 cm−1 region for laser-ablated U atoms codeposited with chloroform in excess argon at 8 K. U and 0.5% CHCl3 in argon codeposited for 1 h (a), after λ > 290 nm irradiation (b), after λ > 220 nm irradiation (c), and after annealing to 30 K (d). U and 0.5% 13CHCl3 in argon codeposited for 1 h (e), and after λ > 220 nm irradiation (f). U and 0.5% CDCl3 in argon codeposited for 1 h (g), and after λ > 220 nm irradiation (h). U and 2% CHBr3 in argon codeposited for 1 h (i), after λ > 290 nm irradiation (j), after λ > 220 nm irradiation (k), and after annealing to 30 K (l).