Chemiluminescent reactions of sulfur atoms and oxygen atoms in solid argon matrices. SO chemiluminescence

• Published in: The Journal of chemical physics 1978-01, Vol.69 (7), p.3182-3189
• Main Authors: Tevault, David E., Smardzewski, Richard R.
• Format: Article
• Language: English
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.436967

When dilute argon matrices containing H2S+O3, OCS+O3 and H2S+NO2 molecules are exposed to ultraviolet radiation and subsequently allowed to warm from 8 to ∼20°K, several intense visible emissions with extensive vibrational structure appear. Besides those emissions of O2, S2, and SO2, two new luminescent systems are evident. Extensive oxygen-18 and deuterium isotopic studies demonstrated the absence of hydrogen and the presence of a single oxygen atom in the emitting species of both systems, while matrix concentration studies established that the excited state species was an intermediate in SO2 formation, presumably molecular SO. The more intense of the two systems is located between 490–870 nm and contains up to ten members. The low values calculated for T0=22 543 cm−1 and ωe″=1130.7 cm−1 suggest that this transition is most likely SO (c1Σ−→ a 1Δ). A second, weaker emission system of SO with approximately eight members was found between 385–600 nm. T0 for this latter system was estimated at 28 400±1150 cm−1, the larger uncertainty being due to the weakness of the system and overlap with SO2 chemiluminescence. The magnitude of T0, as well as the value calculated for ωe″=1157.9 cm−1, is consistent with the assignment of this transition to the SO(A′ 3Δ→X 3Σ−) system which has recently been reported for S2 and O2 chemiluminescence. Ground state oxygen atoms O(3P) were observed to react with H2S in cryogenic matrices to produce only SO2 chemiluminescence, while no emissions were observed in similar experiments with OCS.