Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Hydrogen abstraction from solvents by the triplet state of p-benzoquinone: a time-resolved electron paramagnetic resonance and laser flash photolysis study

Hydrogen abstraction from solvents by the triplet state of p-benzoquinone: a time-resolved... The reaction of triplet p-benzoquinone in several solvents, such as ethanol, 2-propanol, ethylene glycol, t-butanol, 1,4-dioxane, tetrahydrofuran and cyclohexane, has been studied. The primary photochemical event was shown to be a hydrogen atom abstraction from the solvent and not an electron transfer. In the time-resolved EPR experiments, in all cases, except t-butanol and cyclohexane, the radicals from the solvent were recorded along with p-benzosemiquinone radical and the spectra were dominated by triplet mechanism of spin polarization, giving totally emissive EPR signals. The sites of abstracted hydrogen atom have been identified. In particular, whereas the methine hydrogen atom is abstracted from 2-propanol, both the methylene and hydroxyl hydrogen atoms are abstracted from ethanol. From laser flash photolysis experiments, the rate constants of the hydrogen abstraction in all solvents, except t-butanol and cyclohexane, were found to be (1–5) × 108 M−1 s−1. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Research on Chemical Intermediates Springer Journals

Hydrogen abstraction from solvents by the triplet state of p-benzoquinone: a time-resolved electron paramagnetic resonance and laser flash photolysis study

Download PDF
26 pages

Loading next page...
1
 
/lp/springer_journal/hydrogen-abstraction-from-solvents-by-the-triplet-state-of-p-00hOeW05HM

References (2)

Publisher
Springer Journals
Copyright
Copyright © 2005 by VSP
Subject
Chemistry; Inorganic Chemistry; Physical Chemistry; Catalysis
ISSN
0922-6168
eISSN
1568-5675
DOI
10.1163/1568567053146904
Publisher site
See Article on Publisher Site

Abstract

The reaction of triplet p-benzoquinone in several solvents, such as ethanol, 2-propanol, ethylene glycol, t-butanol, 1,4-dioxane, tetrahydrofuran and cyclohexane, has been studied. The primary photochemical event was shown to be a hydrogen atom abstraction from the solvent and not an electron transfer. In the time-resolved EPR experiments, in all cases, except t-butanol and cyclohexane, the radicals from the solvent were recorded along with p-benzosemiquinone radical and the spectra were dominated by triplet mechanism of spin polarization, giving totally emissive EPR signals. The sites of abstracted hydrogen atom have been identified. In particular, whereas the methine hydrogen atom is abstracted from 2-propanol, both the methylene and hydroxyl hydrogen atoms are abstracted from ethanol. From laser flash photolysis experiments, the rate constants of the hydrogen abstraction in all solvents, except t-butanol and cyclohexane, were found to be (1–5) × 108 M−1 s−1.

Journal

Research on Chemical Intermediates – Springer Journals

Published: Jan 1, 2005

There are no references for this article.