51739-98-1Relevant academic research and scientific papers
Pyrolysis of Alkyl Benzenes. Relative Stabilities of Methyl-Substituted Benzyl Radicals
Barton, Barrie D.,Stein, Stephen E.
, p. 2141 - 2145 (1980)
Decomposition rates for β C-C bond scission in several methyl-substituted ethylbenzenes were measured in a very low pressure pyroly (VLPP) system from 1050 to 1200 K, and relative stabilities of the resulting substituted benzyl radicals were derived.Relative to ethylbenzene, rates were highest for o-methyl-substituted ethylbenzenes, and little affected by meta and para substitution.Activation energy differences were approximately separable into ortho and nonortho contributions, amounting to a lowering of the activation energy, relative to ethylbenzene, of 1.3-1.7 kJ/mol per m- or p-CH3, and 5.0-6.3 kJ/mol per o-CH3.Rate differences were explained in terms of a partial relaxation of steric interaction in the activated complex.Methyl inductive effects were found to be very small, amounting to a decrease of 1.7 kJ/mol per CH3 in the Gibbs energy of formation of the radicals produced.
Vibronic spectrum of the jet-cooled 2,6-dimethylbenzyl radical in a corona excitation
Lee, Sang Kuk,Ahn, Byoung Uk,Lee, Sang Kyu
, p. 6554 - 6557 (2003)
A jet-cooled 2,6-dimethylbenzyl radical was generated for the first time from a precursor 2,6-dimethylbenzyl chloride with a large amount of inert carrier gas He in a corona-excited supersonic expansion using a pinhole type glass nozzle. The visible fluorescence emanating from the jet was recorded with a long path monochromator to observe the vibronically resolved jet-cooled emission spectrum. The spectrum was analyzed to obtain accurate electronic transition and active vibrational mode frequencies in the ground electronic state by comparison with those from an ab initio calculation.
