A. Matsumoto, B. Giese
May 20, 1996
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0
Influential Citations
15
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Journal
Macromolecules
Abstract
The structure of methacrylate radicals and other related enolate radicals with various molecular sizes from small molecules to polymers was investigated by ESR spectroscopy. The bromides as precursors for the radicals were prepared by the reaction of the corresponding alkenes with bromotrichloromethane. The radicals were formed by photoirradiation of a toluene solution of the precursor in the presence of hexabutylditin at 213−318 K. The polymer radicals were produced in the ESR tube by the radical polymerization of the corresponding methacrylate with an azo initiator in toluene at 373 K or in p-xylene at 393 K. The ESR spectra of the adduct radicals 1 was revealed to consist of binary components characterized by the following coupling constants and g-values: a1(3H) = 23.4−23.6 G, a2(1H) = 21.6−22.3 G, and g = 2.0043−2.0044 for conformation A and a1(3H) = 23.4−23.5 G and g = 2.0043−2.0044 for conformation B. The α-nitrile radical 9, the dimer or trimer radicals 5−7, and the polymer radicals 8 also gave si...