Addition of CF₃ Radicals to Substituted Benzenes

Activation energies and entropies of activation of CF3radical addition. Part 1.—Gas phase

“…For example, the relative values of k2 reported by Charles, Pearson and Whittle frequently agree within 20-30 % with those reported by Whittemore, Stefani and Szwarc. 3 In conclusion, the spread in true A values may be not as large as indicated by table 2 of Whittle's paper.17 The extremely high value of A J A j = 210 x 10-8 for bromobenzene, given in that table, seems to be in error. Using the data given in tzble 1 we calculated &-$El to be 4.5 k0.5 kcal/mole, instead of 6.7+0-3 given in ref.…”

“…The CF3 radical additions to a series of olefinic, acetylenic and aromatic substrates were studied [1][2][3][4] to establish the reactivity pattern as a function of substrates structure. The relative rate constants k2 of CF3 addition at 65"C, were chosen to measure the substrate reactivities.…”

Thermal Expansion of Caesium Halides with the CsCl Structure

“…Their thermal expansion can help us understand the nature of interatomic forces between ions. Many experiments have measured the thermal expansion of caesium halides (Bridgman, 1932;Menary, Ubbelohde & Woodward, 1951;Johnson, Agron & Bredig, 1955;Krishnan & Srinivasan, 1956;Pathak & Pandya, 1960;Whittemore, 1962;Christian & Lynch, 1964;Majumdar & Roy, 1965;James & Yates, 1965;White, 1965;Morlin & Tremmel, 1966;Bailey & Yates, 1967;Pathak & Vasavada, 1970;Fullam, 1972;White & Collins, 1973;Srivastava & Merchant, 1973;Rapp & Merchant, 1973;Panter, 1974;Ganesan & Girirajan, 1986). Most of the data are listed in the book by Touloukian, Kirby, Taylor & Lee (1977).…”

Electron transference in hemolytic aromatic substitution reactions

“…The reactivities of aromatic molecules toward trifluoromethyl radicals are linearly related to their ionization potentials (2). Methyl (7), ethyl (8), and trichloromethyl(9) affinities of polycyclic aromatics can be correlated to the energies of the HOMO.…”

“…Dipolar effects in homolytic alkylation reactions of aromatic compounds have been suggested as an explanation of the directive effects in the cyclohexylation of substituted benzenes (1) and of the reactivities of substituted benzenes toward the trifluoromethyl radical (2). In order to further elucidate the nature of possible polar effects in homolytic aromatic substitution reactions, we have studied the methylation of naphthalene in a series of solvents.…”