Solvent Effect on the Monomer-Dimer Equilibrium and Dimerization of the 1-Methyl-2-methoxycarbonylpyridinyl Radical

Article abstract of DOI:10.1246/bcsj.58.553

Solvent effects on the hyperfine splitting constants, monomer-dimer equilibrium, and kinetic parameters of the dimerization of the 1-methyl-2-methoxycarbonylpyridinyl radical have been examined in detail, using methylcyclohexane, toluene, 2-methyltetrahydrofuran, acetone, and acetonitrile as the solvents.A comparatively large activation energy for the fast step in the two-step dimerization mechanism suggests strongly that the dimeric intermediate is the 2,2'-dimer of the radical, which subsequently rearranges to the stable 4,4'-dimer.