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rdf:type
pubmed:issue
28
pubmed:dateCreated
2007-7-12
pubmed:abstractText
The photophysical properties of a tetrahedral molecule with naphthalene diimide (NDI) moieties and of two model compounds were investigated. The absorption and fluorescence spectra of dialkyl-substituted NDI are in agreement with literature. While the absorption spectra of phenyl-substituted molecules are similar to all other NDIs, their fluorescence showed a broad band between 500 and 650 nm. This band is sensitive to the polarity of the solvent and is attributed to a CT state. The absorption spectra and lifetime (10+/-2 ps) of the electronically excited singlet state of a dialkyl-substituted NDI was determined by femtosecond transient absorption spectroscopy, and the latter was confirmed by picosecond fluorescence spectroscopy. Nanosecond flash photolysis showed the subsequent formation of the triplet state. The presence of a phenyl substituent on the imide nitrogen of NDI resulted in faster deactivation of the singlet state (lifetime 0.5-1 ps). This is attributed to the formation of a short-lived CT state, which decays to the local triplet state. The faster deactivation was confirmed by fluorescence lifetime measurements in solution and in a low-temperature methyl-tetrahydrofuran glass.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jul
pubmed:issn
1089-5639
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
111
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6151-6
pubmed:year
2007
pubmed:articleTitle
Femtosecond time-resolved photophysics of 1,4,5,8-naphthalene diimides.
pubmed:affiliation
Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands.
pubmed:publicationType
Journal Article