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http://dx.doi.org/10.5012/bkcs.2002.23.2.267

Product-Resolved Photodissociations of Iodotoluene Radical Cations  

Shin, Seung-Koo (FT-ICR Laboratory, Department of Chemistry, Pohang University of Science and Technology)
Kim, Byung-Joo (Division of Chemistry and Radiation, Korea Research Institute of Standards and Science)
Jarek, Russell L. (Department of Chemistry, University of California)
Han, Seung-Jin (Department of Chemistry, University of California)
Publication Information
Bulletin of the Korean Chemical Society / v.23, no.2, 2002 , pp. 267-270 More about this Journal
Abstract
Photodissociations of o-, m-, and p-iodotoluene radical cations were investigated by using Fourier-transform ion cyclotron resonance (FT-ICR) spectrometry. Iodotoluene radical cations were prepared in an ICR cell by a photoionization charge-transfer method. The time-resolved one-photon dissociation spectra were obtained at 532 nm and the identities of $C_7H_7^+$ products were determined by examining their bimolecular reactivities toward toluene-$d_8$. The two-photon dissociation spectra were also recorded in the wavelength range 615-670 nm. The laser power dependence, the temporal variation, and the identities of $C_7H_7^+$ were examined at 640 nm. The mechanism of unimolecular dissociation of iodotoluene radical cations is elucidated: the lowest barrier rearrangement channel leads exclusively to the formation of the benzyl cation, whereas the direct C-I cleavage channel yields the tolyl cations that rearrange to both benzyl and tropylium cations with dissimilar branching ratios among o-, m-, and p-isomers. With a two-photon energy of 3.87 eV at 640 nm, the direct C-I cleavage channel results in the product branching ratio, [tropylium cation]/[benzyl cation], in descending order, 0.16 for meta >0.09 for ortho >0.05 for para.
Keywords
FT-ICR; Time-resolved photodissociation; Iodotoluene; Tolyl cation; Product-resolved photodissociation;
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1 Lifshitz, C.; Levin, I.; Kababia, S.; Dunbar, R. C. J. Phys. Chem. 1991, 95, 1667   DOI
2 Lifshitz, C. Acc. Chem. Res. 1994, 27, 138   DOI   ScienceOn
3 Shin, S. K.; Han, S-J.; Kim, B. Int. J. Mass. Spectrom. Ion Processes 1996, 158, 345   DOI   ScienceOn
4 Kim, B.; Shin, S. K. J. Chem. Phys. 1997, 106, 1411   DOI   ScienceOn
5 McLafferty, F. W.; Winkler, J. J. Am. Chem. Soc. 1974, 96, 5182   DOI
6 McLafferty, F. W.; Bockhoff, F. M. J. Am. Chem. Soc. 1979, 101, 1783   DOI
7 Olesik, S.; Baer, T.; Morrow, J. C.; Ridal, J. J.; Buschek, J.; Holmes, J. L. Org. Mass Spectrom. 1989, 24, 1008   DOI
8 Dunbar, R. C.; Lifshitz, C. J. Chem. Phys. 1989, 94, 3542
9 Lin, C. Y.; Dunbar, R. C. J. Phys. Chem. 1994, 98, 1369   DOI   ScienceOn
10 Proctor, C. J.; McLafferty, F. W. Org. Mass Spectrom. 1983, 18, 193   DOI
11 Dunbar, R. C.; Honovich, J. P.; Asamoto, B. J. Phys. Chem. 1988, 92, 6935   DOI
12 Choe, J. C.; Kim, M. S. Int. J. Mass. Spectrom. Ion Processes 1991, 107, 103   DOI   ScienceOn
13 Cho, Y. S.; Kim, M. S.; Choe, J. C. Int. J. Mass. Spectrom. Ion Processes 1995, 145, 187   DOI   ScienceOn
14 Lu, K. T.; Eiden, G. C.; Weisshaar, J. C. J. Phys. Chem. 1992, 96, 9742   DOI
15 Jackson, J.-A. A.; Lias, S. G.; Ausloos, P. J. Am. Chem. Soc. 1977, 99, 7515   DOI
16 Shin, S. K. Chem. Phys. Lett. 1997, 280, 260   DOI   ScienceOn
17 Kim, B.; Shin, S. K., unpublished
18 McCrery, D. A.; Freiser, B. S. J. Am. Chem. Soc. 1978, 100, 2902   DOI
19 Shen, J.; Dunbar, R. C.; Olah, G. A. J. Am. Chem. Soc. 1974, 96, 6227
20 Ignatyev, I. S.; Sundius, T. Chem. Phys. Lett. 2000, 326, 101   DOI   ScienceOn