PHOTOCHEMISTRY OF CHLORINE DIOXIDE IN ICE

The photochemistry of chlorine dioxide, OClO, in amorphous ice has bee n investigated using FTIR and UV-vis spectroscopy. Exposure to ultravi olet light (lambda = 360 nm) quantitatively converted the OClO to the chlorine peroxy radical, ClOO. The asymmetric stretch of OClO at 1100 cm(-1) and the O-O stretch of ClOO at 1440 cm(-1), along with the char acteristic UV absorptions at 360 and 260 nm, respectively, were used f or monitoring the photochemical process, Under the dilute conditions u sed, the only photoproduct appears to be ClOO, in contrast with the ga s-phase photolysis which yields predominantly ClO. These findings have implications for stratospheric ozone loss, Namely, the photochemical conversion of OClO to ClOO in stratospheric ice particles may represen t a new ozone-depleting mechanism.