Extension of structure-reactivity correlations for the hydrogen abstraction reaction to methyl radical and comparison to chlorine atom, bromine atom, and hydroxyl radical

Journal Article · Tue Jun 07 00:00:00 EDT 2016 · Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory

DOI:https://doi.org/10.1021/acs.jpca.6b04357· OSTI ID:1263858

Poutsma, Marvin L. ^[1]

---

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

In this study, we presented structure-reactivity correlations for the gas-phase rate constants for hydrogen abstraction from sp3-hybridized carbon by three electrophilic radicals (X^• + HCR₃ → XH + ^•CR₃; X = Cl^•, HO^•, and Br); the reaction enthalpy effect was represented by the independent variable Δ_rH and the polar effect by the independent variables F and R, the Hammett-Taft constants for field/inductive and resonance effects. Here we present a parallel treatment for the less electronegative CH₃^•. In spite of a limited and scattered data base, the resulting least-squares fit [log k₄₃₇(CH₃^•) = 0.0251(Δ_rH) + 0.96(ΣF) 0.56(ΣR) – 19.15] was modestly successful and useful for initial predictions. As expected, the polar effect appears to be minor and its directionality, i.e., the philicity of CH₃, may depend on the nature of the substituents.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1263858
• Journal Information: Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory, Vol. 120, Issue 26; ISSN 1089-5639
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY