A study of the bimolecular intersystem crossing reaction induced in the first excited singlet of SO2 by collisions with O2 and other atmospheric gases

✍ Scribed by Fred B. Wampler; Jack G. Calvert; Edward K. Damon

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 524 KB
• Volume: 5
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550050110

✦ Synopsis

The relative intensities of phosphorescence of S02(3B1) molecule: have been determined following the optical excitation of S02('BI) molecules by a 2662 A laser pulse. From a kinetic treatment of these measurements, the intersystem crossing ratio, k2b/(klb + kzb), was determined; SOZ(

With ha = 0 2 , N2, Ar, CO?, and C o , k 2 b / ( k i b + k 2 b ) = 0.030 i 0.013, 0.034 + 0.029, 0.025 +: 0.005, 0.052 i 0.014, and 0.045 j= 0.028, respectively. These data allow a new, more quaatitative evaluation of the extent of involvement of the ''excess'' triplet SO2 in the 31 30 A-irradiated mixtures of SO? and CO at high pressures [5,6]. The new data are also of direct interest in the determination of the theoretical maximum rates of photooxidation of SO:! in the sunlight-irratiated atmosphere of the earth.

'' Reference 12. " Reference 13.

References 8 and 6.

degradation paths of reactions (1) and ( 2) is probably controlled largely by the properties of the SO, molccule, that is, the relative density of states in the triplet and the singlet state manifolds near the vibronic level of the excited singlet and and the extent of the mixing of the singlet and triplet states.