PTOC Esters Research Articles

Picosecond radical kinetics. Ring openings of phenyl-substituted cyclopropylcarbinyl radicals

Rate constants for ring openings of the trans-(2-phenylcyclopropyl)carbinyl radical (1a), the cis-(2-phenylcyclopropyl)carbinyl radical (1b), and the (2,2-diphenylcyclopropyl)carbinyl radical (1c) were studied by competition kinetics using PTOC esters as radical precursors and hydrogen atom transfer trapping from benzeneselenol as the basis reaction. Radical 1a was studied in two solvents, toluene and THF; the experimental Arrhenius function for ring opening of 1a was log (κ r .s)=13.9-3.3/2.3RT (R in kcal/mol)