Rate constants for the addition of the 2-cyano-2-propyl radical to alkenes in solution

Article abstract of DOI:10.1002/kin.550250405

Absolute rate constants for the addition of the 2-cyano-2-propyl radical to 26 alkenes CH₂ = CXY at 315 K were determined in solution by time-resolved electron-spin-resonance spectroscopy. They vary with the alkene substituents from 30 M^-1 s^-1 to 7′010 M^-1 s^-1. For styrene the temperature dependence is given by log k/M^-1 s^-1 = 7.7 - 26.1/Θ where Θ = 2.303 RT in kJ/mol. An analysis of the substituent effects in terms of polar and enthalpic factors reveals a dominant influence of the overall reaction enthalpy.