A spectroscopic and photoisomerisation study of bromine dioxides in argon matrices Original Research Article

The FTIR and UV spectra of OBrO have been measured in solid argon matrices at 17 and 4 K. All three fundamentals of OBrO could be observed. The previously unknown frequency of the bending vibration (ν2) was located at 317.0/316.3 cm−1 for 16O79Br16O/16O81Br16O and at 302.1/301.4 cm−1 for 18O79Br18O/18O81Br18. OBrO was synthesised by photoisomerising BrOO at 275 nm. The BrOO/argon matrix was prepared by adding bromine atoms from a discharge flow system to molecular oxygen on the surface of a growing argon matrix. We show that the photoisomerisation of BrOO to OBrO is reversible. In addition the wavelength dependency of the OBrO and BrOO photochemistry in argon matrices and the isomerisation rate has been determined in the wavelength range from 200 to 600 nm.