Time-Resolved Gas Electron-Diffraction Study of the 193-Nm Photolysis of 1,2-Dichloroethenes
by Ewbank, J. D.; Luo, J. Y.; English, J. T.; Liu, R. F.; Faust, W. L.; Schafer, L.
We have employed time-resolved gas electron diffraction. using an excite-and-probe technique developed on the basis of various precedents,1-2 for study of the 193-nm photodissociation of isomeric 1,2-dichloroethenes. The procedure3 involves a pulsed electron beam synchronous with photoexcitation and on-line electron diffraction intensity recording with a photodiode array. When the time delay between excitation and diagnostic electron scattering is 15 ns, only fragmentation and no cis-trans somerization is observed. When the time delay is several milliseconds, cis-trans isomerization is prevalent. This finding confirms the thesis that, because of faster intervening dissociative processes, cis-trans isomerization is not a primary photochemically driven unimolecular rearrangement of 193-nm irradiated dichloroethenes but hinges upon intermolecular collisions.
- Journal
- Journal of Physical Chemistry
- Volume
- 97
- Issue
- 34
- Year
- 1993
- Start Page
- 8745-8751
- URL
- https://dx.doi.org/10.1021/j100136a016
- ISBN/ISSN
- 0022-3654
- DOI
- 10.1021/j100136a016