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Kinetics of the photoinduced dissociative reduction of the model alkyl peroxides di-tert-butyl peroxide and ascaridole
| Content Provider | Semantic Scholar |
|---|---|
| Author | Magri, David C. Workentin, Mark S. |
| Copyright Year | 2012 |
| Abstract | Rate constants for the reaction between excited singlet state aromatic donors and the dialkyl peroxide, di-tert-butyl peroxide (DTBP), and the bicyclic endoperoxide, ascaridole (ASC), were measured in acetonitrile using fluorescence quenching techniques. The rate constants, measured with 18 different aromatic donors by Stern-Volmer quenching, range from 9.2 109 to 4.4 106 M-1 s-1. Using accurately measured standard reduction potentials for the peroxides, the driving force for photoinduced electron transfer is predicted to be thermodynamically feasible over the entire range of excited donors ranging from 49 to 10 kcal mol-1 for ASC and 38 to 2 kcal mol-1 for DTBP. However, when the photoinduced kinetics are combined with previously measured electron transfer kinetics by homogeneous redox catalysis with ground state radical-anion donors, a smooth parabolic correlation for a dissociative electron transfer mechanism is not observed. Rather, a discontinuity is observed between the photochemical and electrochemical data sets with the rate constants with singlet excited states donors being over two orders of magnitude larger than the ground state kinetics at the same driving force. The discrepancy is examined considering the importance of attractive interaction between fragments in the dissociative photoinduced electron transfer reactions. |
| Starting Page | 303 |
| Ending Page | 315 |
| Page Count | 13 |
| File Format | PDF HTM / HTML |
| DOI | 10.13171/mjc.1.6.2012.10.06.13 |
| Volume Number | 1 |
| Alternate Webpage(s) | http://ojs.medjphysics.com/index.php/medjchem/article/download/133/106 |
| Alternate Webpage(s) | https://doi.org/10.13171/mjc.1.6.2012.10.06.13 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
