93824-69-2Relevant academic research and scientific papers
Absolute Rate Constants for the Addition of Hydroxymethyl Radicals to Alkenes in Methanol Solution
Wu, J. Q.,Fischer, H.
, p. 167 - 180 (1995)
Absolute rate constants and their temperature dependencies were determined for the addition of hydroxymethyl radicals (.CH2OH) to 20 mono- or 1,1-disubstituted alkenes (CH2 = CXY) in methanol by time-resolved electron spin resonance spectroscopy.With the alkene substituents the rate constants at 298 K (k298) vary from 180 M-1s-1 (ethyl vinylether) to 2.1*106 M-1s-1 (acrolein).The frequency factors obey log A/M-1s-1 = 8.1 +/- 0.1, whereas the activation energies (Ea) range from 11.6 kJ/mol (methacrylonitrile) to 35.7 kJ/mol (ethyl vinylether).As shown by good correlations with the alkene electron affinities (EA), log k298/M-1s-1 = 5.57 + 1.53 * EA/eV (R2 = 0.820) and Ea = 15.86 - 7.38 * EA/eV (R2 = 0.773), hydroxymethyl is a nucleophilic radical, and its addition rates are strongly influenced by polar effects.No apparent correlation was found between Ea or log k298 with the overall reaction enthalpy.
