Photochemical reactions of ClF and BrF with hydrogen in solid argon. Infrared spectra of mixed hydracid dimers

Argon diluted samples of H₂ and ClF were codeposited at 10 K, and no reaction was observed. Photolysis produced a sharp 2834.5, 2832.5 cm ^-1 doublet, in agreement with (HF) (HCl) dimer from HF and HCl codeposition experiments. Irradiation at 14-16 K markedly increased the mixed dimer and produced weak monomer and dimer bands of HCl and HF, mixed trimer absorptions, and a sharp band at 3857.9 cm^-1 for the Cl-HF radical complex. In similar experiments with HD, two mixed dimers, (HF) (DCl) and (HCl) (DF), were formed; likewise, photolyzing D₂ with ClF produced two mixed dimers of the form (DF) (DCl) and (DCl) (DF). In the H₂ and BrF system, photolysis produced a sharp absorption at 3814.6 cm^-1, in agreement with (HBr) (HF) dimer from HBr and HF codeposition experiments, and a new 3830.5 cm^-1 band due to the Br-HF radical complex. In a parallel study with HD, two mixed dimers, (HBr) (DF) and (DBr) (HF), were observed while only one mixed dimer, (DBr) (DF), was formed by BrF and D₂. In complementary experiments with H₂ and Cl₂, (HCl) ₂ was observed at 2818.1 and 2816.2 cm^-1.