| Popis: |
A new kinetic scheme for the dissociation of I 2 by O 2 (a) has been proposed by Azyazov et al. (J. Chem. Phys. 130, 104306/9 (2009)). In principle, the reactions initiated by UV photolysis of N 2 O/I 2 mixtures can be used to probe the chain propagation stage of this dissociation model, and provide additional validation. In the present study, 193 nm laser photolysis of N 2 O/I 2 mixtures was used to initiate secondary chemical reactions and to produce iodine atoms. Singlet oxygen was generated in this system by the fast reaction O( 1 D)+N 2 O→ O 2 (a)+N 2 . Emission spectroscopy and laser induced fluorescence techniques were used to follow the time evolutions of I* and I 2 . The photolysis of N 2 O/I 2 mixtures creates all of the species needed to sustain the chain propagation stage of I 2 dissociation process. However, it was found that the high pressures of N 2 O needed to generate sufficient concentrations of O 2 (a) suppressed the I 2 dissociation process. Computational modeling indicated that suppression of the chain propagation reactions under the conditions examined was consistent with the revised dissociation model. |
