Investigation of the structure and reactivity of the stable perfluorodiisopropylethylmethyl radical by ESR and molecular mechanics
Abstract
The hyperfine coupling (HFC) constants of the unpaired electron with the fluorine nuclei in the stable radical [(CF3)2CF]2ĊCF2CF3 (II) were determined by ESR. The stable conformation and the barriers to rotation of the substituents in this radical were calculated by molecular mechanics. The results were consistent with the ESR data. The kinetics of the destruction of the radical (II) were investigated, and the kinetic parameters of the dissociation were determined (k140=4.6·10−4 sec−1, Eact=30±5 kcal/mole). The disappearance of the radical (II) is accompanied by the accumulation of the new radical (CF3)2CFĊ(CF3)CF(CF3)CF2CF3 (IV), which was studied by ESR. Heating of (II) in the presence of electron donors leads to the partly reversible reduction of the radical (II).
Keywords
Molecular Mechanic Kinetic Parameter Fluorine Electron Donor Unpaired ElectronPreview
Unable to display preview. Download preview PDF.
Literature cited
- 1.K. V. Schrer, Jr., T. Ono, K. Yamanouchi, et al., J. Am. Chem. Soc.,107, 718 (1985).Google Scholar
- 2.B. L. Tumanskii, S. P. Solodovnikov, and E. V. Zakharova, Izv. Akad. Nauk SSSR, Ser. Khim., No. 10, 2371 (1989).Google Scholar
- 3.F. Cavagna and C. Shumann, J. Magn. Reson.,22, 333 (1976).Google Scholar
- 4.B. L. Tumanskii, T. V. Timofeeva, and A. A. Kadyrov, Dokl. Akad. Nauk SSSR,312, 1152 (1990).Google Scholar
- 5.U. Burkert and N. L. Allinger (eds.), ACS Monograph No. 177: Molecular Mechanics, ACS, Washington, D.C. (1982).Google Scholar
- 6.S. V. Sereda, M. Yu. Antipin, and L. L. Gervits, Izv. Akad. Nauk SSSR, Ser. Khim., No. 7, 1549 (1989).Google Scholar
- 7.V. V. Voevodskii, Physics and Chemistry of Elementary Chemical Processes [in Russian], Nauka, Moscow (1969), p. 94.Google Scholar