Linked Life Data

18399913

Source:http://linkedlifedata.com/resource/pubmed/id/18399913

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2008-9-2
pubmed:abstractText
The BF(3)-catalyzed photodimerization of parent coumarin (1), three 6-alkylcoumarins (2-4) and N-methyl-2-quinolone (5) in dichloromethane was studied by time-resolved UV-vis spectroscopy. The lowest triplet state properties in the absence and presence of BF(3) were outlined, in particular the effect of self-quenching which initiates dimerization. The quantum yield of intersystem crossing (Phi(isc)) of 1-4 increases with BF(3) concentration, approaching Phi(isc) = 0.3. Phi(isc) and the relative quantum yield of dimerization go along, thereby favoring an overall triplet mechanism in both the direct and BF(3)-catalyzed photodimerization. The product ratio of 5 changes strongly with the BF(3) concentration from 100%anti-hh for the free quinolone to 100%syn-ht for the 1:1 complex.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0031-8655
pubmed:author
pubmed:issnType
Print
pubmed:volume
84
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1224-30
pubmed:meshHeading
pubmed:articleTitle
Lewis-acid-catalyzed photodimerization of coumarins and N-methyl-2-quinolone.
pubmed:affiliation
Max-Planck-Institut für Bioanorganische Chemie, Mülheim an der Ruhr, Germany. goerner@mpi-muelheim.mpg.de
pubmed:publicationType
Journal Article