Linked Life Data

19061320

Source:http://linkedlifedata.com/resource/pubmed/id/19061320

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
52
pubmed:dateCreated
2009-1-5
pubmed:abstractText
The factors that control the reactivities of aryl radicals toward hydrogen-atom donors were studied by using a dual-cell Fourier-transform ion cyclotron resonance mass spectrometer. Hydrogen-atom abstraction reaction efficiencies for two substrates, cyclohexane and isopropyl alcohol, were measured for 23 structurally different, positively charged aryl radicals, which included dehydrobenzenes, dehydronaphthalenes, dehydropyridines, and dehydro(iso)quinolines. A logarithmic correlation was found between the hydrogen-atom abstraction reaction efficiencies and the (calculated) vertical electron affinities (EA) of the aryl radicals. Transition state energies calculated for the reaction of three of the aryl radicals with isopropyl alcohol were found to correlate linearly with their (calculated) EAs. No correlation was found between the hydrogen-atom abstraction reaction efficiencies and the (calculated) enthalpy changes for the reactions. Measurement of the reaction efficiencies for the reactions of 15 different hydrogen-atom donors with two selected aryl radicals revealed a logarithmic correlation between the hydrogen-atom abstraction reaction efficiencies and the vertical ionization energies (IE) of the hydrogen-atom donors, but not the lowest homolytic X-H (X = heavy atom) bond dissociation energies of the hydrogen-atom donors. Examination of the hydrogen-atom abstraction reactions of 29 different aryl radicals and 18 different hydrogen-atom donors showed that the reaction efficiency increases (logarithmically) as the difference between the IE of the hydrogen-atom donor and the EA of the aryl radical decreases. This dependence is likely to result from the increasing polarization, and concomitant stabilization, of the transition state. Thus, the hydrogen-atom abstraction reaction efficiency for an aryl radical can be "tuned" by structural changes that influence either the vertical EA of the aryl radical or the vertical IE of the hydrogen atom donor.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-10836065, http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-11782134, http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-11942850, http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-12590557, http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-12729660, http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-14664625, http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-15144982, http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-15771534, http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-16928123, http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-3565762, http://linkedlifedata.com/resource/pubmed/commentcorrection/19061320-8388732
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
31
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17697-709
pubmed:dateRevised
2010-12-17
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Correlation of hydrogen-atom abstraction reaction efficiencies for aryl radicals with their vertical electron affinities and the vertical ionization energies of the hydrogen-atom donors.
pubmed:affiliation
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural