Benzoannelated aza-, oxa- and azaoxacirculenes as promising blue organic emitters
2016 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, no 40, 28040-28051 p.Article in journal (Refereed) Published
In the present work, we studied the synergetic effect of benzoannelation and NH/O-substitution for enhancing the absorption intensity in a series of novel designed benzoannelated aza- and oxacirculenes. Semi-empirical estimations of the fluorescence rate constants allowed us to determine the most promising fluorophores among all the possible benzoannelated aza-, oxa- and mixed azaozacirculenes. Among them, para-dibenzoannelated circulenes demonstrated the most intense light absorption and emission due to the prevailing role of the linear acene chromophore. Calculated phi(fl) values are in complete agreement with experimental data for a number of already synthesized circulenes. Thus, we believe that the most promising circulenes designed in this study can demonstrate an intensive fluorescence in the case of their successful synthesis, which in turn could be extremely useful for the fabrication of future blue OLEDs. Special attention is devoted to the aromaticity features and peculiarities of the absorption spectra for the two highly-symmetrical (D-4h ground state symmetry) pi-isoelectronic species as well as the so-called tetrabenzotetraazacirculene and tetrabenzotetraoxacirculene molecules. Both of them are characterized by rich electronic spectra, which can be assigned only by taking into account the vibronic coarse structure of the first electronic absorption band; the 0-1 and 0-2 transitions were found to be active in the absorption spectrum in complete agreement with experimental data obtained for both energy and intensity. The corresponding promotive vibrational modes have been determined and their vibronic activity estimated using the Franck-Condon approximation.
Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY , 2016. Vol. 18, no 40, 28040-28051 p.
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:kth:diva-196386DOI: 10.1039/c6cp03060bISI: 000385180600038PubMedID: 27711404ScopusID: 2-s2.0-84991660782OAI: oai:DiVA.org:kth-196386DiVA: diva2:1050426
QC 201611242016-11-292016-11-142016-11-29Bibliographically approved