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rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2006-7-12
pubmed:abstractText
The electronic absorption spectra of a series of alkoxy-styryl substituted terthiophenes, their corresponding sexithiophenes, and the oxidation products of both have been measured. The terthiophenes studied sigma-dimerize to sexithiophenes during the oxidation process and there is clear evidence of sexithiophene radical cations, dications, and pi-dimers in the electronic absorption spectra. The oxidation of concentrated solutions produces predominantly pi-dimer bands, as expected. The absorption spectrum of the styryl-functionalized sexithiophene dication without alkoxy substitution closely resembles that of unsubstituted sexithiophene, while alkoxy substitution induces changes in the wavelength of the dication band maximum and the overall band shape. Time-dependent density functional theory (TDDFT) calculations have shown that styryl-based molecular orbitals are important in the transitions of the neutral molecules as well as the charged species, the dication in particular. Kinetics analyses confirm the stabilization effect induced by the alkoxy substituents. The presence of a reversible pi-dimer equilibrium was verified by cyclic voltammetry. It is clear from the experimental observations and the theoretical calculations that both the styryl and alkoxy groups are influencing the electronic properties of this class of molecules.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Mar
pubmed:issn
1089-5639
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
109
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1961-73
pubmed:year
2005
pubmed:articleTitle
Characterization of the oxidation products of styryl-substituted terthiophenes and sexithiophenes using electronic absorption spectroscopy and time-dependent DFT.
pubmed:affiliation
Department of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand.
pubmed:publicationType
Journal Article