Cation Radical Polymerization. A Fundamentally New Polymerization Mechanism

Electron-transfer catalyzed cycloaddition reactions of unactivated cyclic olefins in weakly coordinating anion electrolyte

“…The key factor in the initiation step, namely the comparative E1/2 potentials of the olefin and the redox agent, has been discussed in a number of papers. 1,9,[14][15][16][17][18] It has been specifically stated that these reactions will not proceed at discernible rates unless the potential of the catalyst is within about 500 mV of that of the olefin. [16][17][18] In fact, a catalyst seems to be most effective if its oxidation potential is a few hundred millivolts less than that of the olefin.…”

Cation radical chain cycloaddition polymerization and cationic macrocyclopolymerization

“…The abundant presence of cyclobutapolymer linkages was evident from the (broad) 1 H NMR absorption of d 1.15, which is characteristic of methyl groups attached to a cyclobutane ring. To further corroborate the proposed cyclobutapolymer structure, the model compound 4 was prepared via a monofunctional reaction analogous to that presumed to be involved in the polymerization of 3 (Scheme 5).…”

“…High ®eld 1 H NMR spectra were recorded on a General Electric GN-500 spectrometer. Chemical shifts (d) are reported in parts per million down®eld from a tetramethylsilane reference, and coupling constants (J) are given in hertz.…”

“…Column chromatography on silica gel (hexanes:ethyl acetate = 13:1) afforded the pure product (14 g, 77.5%): 1 H NMR (CDCl 3 , 250 MHz), d 3.42 (d, 2H, J = 6.67), 3.68 (t, 2H, J = 6.11), 4.31 (t, 2H, J = 6.11), 5.06 (dd, 2H, J = 15.2, 9.51), 6.0 (m, 1H), 6.82 (d, 1H, J = 8.2), 6.98 (d, 1H, J = 7.32), 7.18 (d, 2H, J = 7.2); LRMS, m/e 242 (M 1); HRMS, calculated for C 11 H 13 OBr 241.022801, found 241.022823.…”

Chemical trapping experiments support a cation-radical mechanism for the oxidative polymerization of aniline

“…Arylamine cationradicals can add to alkenes. [31][32][33] Therefore, the formation of addition compounds between aniline and alkenes would be strong evidence for the intermediacy of anilinium cation-radical.…”