A SPECTROSCOPIC AND PHOTOISOMERIZATION STUDY OF BROMINE DIOXIDES IN ARGON MATRICES

The FTIR and UV spectra of OBrO have been measured in solid argon matr ices at 17 and 4 K. All three fundamentals of OBrO could be observed, The previously unknown frequency of the bending vibration (nu(2)) was located at 317.0/316.3 cm(-1) for (OBrO)-O-16-Br-79-O-16/(OBrO)-O-16-B r-81-O-16 and at 302.1/301.4 cm(-1) for (OBrO)-O-18-Br-79-O-18/(OBrO)- O-18-Br-81-O-18. 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 r eversible. In addition the wavelength dependency of the OBrO and BrOO photochemistry in argon matrices and the isomerisation rate has been d etermined in the wavelength range from 200 to 600 nm.