10.1021/jp802257m.s001
Linhong Jing
Linhong
Jing
Leonard P. Guler
Leonard P.
Guler
George Pates
George
Pates
Hilkka I. Kenttämaa
Hilkka I.
Kenttämaa
The Selectivity of Charged Phenyl Radicals in Hydrogen Atom Abstraction Reactions with Isopropanol
American Chemical Society
2008
ion cyclotron resonance
selectivity
CH 3 group
isotope effects decrease
CD 3 group
CH group
phenyl radicals correlates
Hydrogen Atom Abstraction Reactions
hydrogen atom abstraction
isopropanol
electron affinity
deuterium atom abstraction
Charged Phenyl Radicals
OH
electron affinity increases
2008-10-09 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/The_Selectivity_of_Charged_Phenyl_Radicals_in_Hydrogen_Atom_Abstraction_Reactions_with_Isopropanol/2908501
The vertical electron affinity is demonstrated to be a key factor in controlling the selectivity of charged phenyl radicals in hydrogen atom abstraction from isopropanol in the gas phase. The measurement of the total reaction efficiencies (hydrogen and/or deuterium atom abstraction) for unlabeled and partially deuterium-labeled isopropanol, and the branching ratios of hydrogen and deuterium atom abstraction, by using a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer, allowed the determination of the selectivity for each site in the unlabeled isopropanol. Examination of hydrogen atom abstraction from isopropanol by eight structurally different radicals revealed that the preferred site is the CH group. The selectivity of the charged phenyl radicals correlates with the radical’s vertical electron affinity and the reaction efficiency. The smaller the vertical electron affinity of a radical, the lower its reactivity, and the greater the preference for the thermodynamically favored CH group over the CH<sub>3</sub> group or the OH group. As the vertical electron affinity increases from 4.87 to 6.28 eV, the primary kinetic isotope effects decrease from 2.9 to 1.3 for the CD group, and the mixture of primary and α-secondary kinetic isotopes decreases from 6.0 to 2.4 for the CD<sub>3</sub> group.