Picosecond radical kinetics. Rate constants for reaction of benzeneselenol with primary alkyl radicals and calibration of the 6-cyano-5-hexenyl radical cyclization

Abstract

The cyclopropylcarbinyl radical ring opening was used as a radical clock to determine rate constants for benzeneselenol trapping in THF and in toluene. Hydrogen atom transfer trapping from PhSeH appeared to be partially diffusion controlled. An operational Arrhenius function for trapping in THF is log (k T .M s)=11.03-2.27/2.3RT. The recommended function for PhScH trapping in other low-viscosity organic solvents is log (k T .M s)=10.87-2.10/2.3RT. The rate constant for trapping at 25 o C is 2.1×10 9 M -1 s -1