Soluble Flavanthrone Derivatives: Synthesis, Characterization, and Application to Organic Light-Emitting Diodes.
Simple modification of benzo[h]benz[5,6]acridino[2,1,9,8-klmna]acridine-8,16-dione, an old and almost-forgotten vat dye, by reduction of its carbonyl groups and subsequent O-alkylation, yields solution-processable, electroactive, conjugated compounds of the periazaacene type, suitable for the use in organic electronics. Their electrochemically determined ionization potential and electron affinity of about 5.2 and -3.2 eV, respectively, are essentially independent of the length of the alkoxyl substituent and in good agreement with DFT calculations. The crystal structure of 8,16-dioctyloxybenzo[h]benz[5,6]acridino[2,1,9,8-klmna]acridine (FC-8), the most promising compound, was solved. It crystallizes in space group P1‾ and forms π-stacked columns held together in the 3D structure by dispersion forces, mainly between interdigitated alkyl chains. Molecules of FC-8 have a strong tendency to self-organize in monolayers deposited on a highly oriented pyrolytic graphite surface, as observed by STM. 8,16-Dialkoxybenzo[h]benz[5,6]acridino[2,1,9,8-klmna]acridines are highly luminescent, and all have photoluminescence quantum yields of about 80 %. They show efficient electroluminescence, and can be used as guest molecules with a 4,4'-bis(N-carbazolyl)-1,1'-biphenyl host in guest/host-type organic light-emitting diodes. The best fabricated diodes showed a luminance of about 1900 cd m(-12) , a luminance efficiency of about 3 cd A(-1) , and external quantum efficiencies exceeding 0.9 %.
Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland.
Kamil
K
Kotwica
Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland. piotrbujakchem@poczta.onet.pl.
Piotr
P
Bujak
Physics Department, University of Durham, South Road, Durham, DH1 3LE, UK.|Faculty of Chemistry, Silesian University of Technology, M. Strzody 9, 44-100, Gliwice, Poland.
Przemyslaw
P
Data
Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland.
Wojciech
W
Krzywiec
Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland.
Damian
D
Wamil
Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland.
Piotr A
PA
Gunka
Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland.
Lukasz
L
Skorka
Institute of Physical Chemistry, Polish Academy of Science, Kasprzaka 44/52, 01-224, Warsaw, Poland.
Tomasz
T
Jaroch
Institute of Physical Chemistry, Polish Academy of Science, Kasprzaka 44/52, 01-224, Warsaw, Poland.
Robert
R
Nowakowski
Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland.
Adam
A
Pron
Physics Department, University of Durham, South Road, Durham, DH1 3LE, UK. a.p.monkman@durham.ac.uk.
Andrew
A
Monkman
alkylation; dyes/pigments; luminescence; self-assembly; semiconductors