Matrix-isolation infrared spectra of HOOBr and HOBrO produced upon VUV light irradiation of HBr/O2/Ne system

Vacuum ultraviolet (VUV) light photolysis of an HBr/O2 mixture in a Ne matrix has produced HO2Br isomers (HOOBr and HOBrO), which are important reaction intermediates in atmospheric chemistry. The observed bands have been assigned with an aid of a quantum chemical calculation at CCSD/aug-cc-pVDZ. These assignments have been confirmed by the experimental results using isotopic species of 18O2 or DBr. Their characteristic bands are discussed in comparison with those of HOOCl and HOClO from an HCl/O2 mixture [7]. Both HOOBr and HOBrO are found to be photolyzed with the UV light below 385 nm.