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Probing the photoreactivity of aryl chlorides with oxygen

dc.contributor.authorSilva, José P. da
dc.contributor.authorJockusch, Steffen
dc.contributor.authorTurro, Nicholas J.
dc.date.accessioned2015-06-22T14:13:53Z
dc.date.available2015-06-22T14:13:53Z
dc.date.issued2009
dc.description.abstractMolecular oxygen was used to probe the mechanism of the phototransformation of chlorobenzene and 4-chloroanisole in organic solvents. Laser. ash photolysis, electron paramagnetic resonance and product distribution studies clarified the reaction mechanisms of these compounds under a wide range of conditions. The main primary photochemical reaction step is the homolytic cleavage of the C-Cl bond to produce a triplet radical pair in the solvent cage. In non-polar solvents hydrogen abstraction, after radical diffusion, leads to reduction. In polar solvents, in addition to H-abstraction, electron transfer within the caged radical pair occurs and leads to an ion pair (phenyl cation and Cl(-)). In the presence of oxygen, phenyl radicals can form phenylperoxyl radicals which have a bathochromically shifted absorption, thus making the homolytic cleavage visible by. ash photolysis. The peroxyl radicals can couple, leading to more polar compounds, or undergo back reaction to the phenyl radical. For concentrations of the aryl chlorides of higher than 10(-3) M, dimerization becomes an important transformation process and occurs after reaction of the transients with ground state molecules. In addition, excimer formation is postulated to be involved in the dimerization process.
dc.identifier.doihttps://dx.doi.org/10.1039/b815039g
dc.identifier.issn1474-905X
dc.identifier.urihttp://hdl.handle.net/10400.1/6588
dc.language.isoeng
dc.peerreviewedyes
dc.publisherRoyal Society of Chemistry
dc.relation.isbasedonP-003-RM8
dc.titleProbing the photoreactivity of aryl chlorides with oxygen
dc.typejournal article
dspace.entity.typePublication
oaire.citation.endPage216
oaire.citation.startPage210
oaire.citation.titlePhotochemical & Photobiological Sciences
oaire.citation.volume8
person.familyNameSilva
person.givenNameJosé Paulo da
person.identifier.ciencia-id3413-C4F4-73F7
person.identifier.orcid0000-0002-6458-7328
person.identifier.ridA-4606-2008
person.identifier.scopus-author-id7201733236
rcaap.rightsopenAccess
rcaap.typearticle
relation.isAuthorOfPublicatione2004fa2-a47d-44b0-b11c-fc95fe51cbf9
relation.isAuthorOfPublication.latestForDiscoverye2004fa2-a47d-44b0-b11c-fc95fe51cbf9

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