Codeposition of argon dilute samples of O3and CO produced new narrow absorption lines which are assigned to the CO:O3complex. One line appears at 2140.44 cmminus;1, 2 cmminus;1above the CO frequency which shows that it is a weakly bonded complex. Its spectrum exhibits three new lines near the ngr;3doublet of O3. The two lines observed at 1042.56 and 1043.37 cmminus;1appear clearly at 5 K; the lowest frequency one, at 1041.35 cmminus;1, is overlapped at 5 K by the high frequency component of the ngr;3doublet of isolated O3and can only be detected when the temperature is raised, as it is almost not temperature dependent up to 20 K. Irradiation of the sample at 5 K with the 266 nm emission of a quadrupled NDhyphen;YAG laser leads to an efficient decomposition of free and complexed ozone and an increase of CO2with two regimes, a fast beginning similar to the O3and CO:O3decays followed by a much slower one. After such an irradiation at 5 K, some recombination of O3and CO:O3is observed during a warming at 10 K. A careful analysis of the relative intensities variation shows that CO2is only produced inside the CO:O3complex, from the reaction of CO with1Datomic oxygen. As1Doxygen atoms are very fastly relaxed to3Pones during their migration through the matrix, isolated CO does not react. We have shown evidence of a very limited migration of atomic oxygen at 5 K in solid argon, and of an efficient one at 10 K.
展开▼
