Synthesis of J-aggregating dibenz [a, j] anthracene-based macrocycles

Publication Type:

Journal Article

Source:

J. Am. Chem. Soc., ACS Publications, Volume 131, Issue 15, p.5659-5666 (2009)

ISBN:

0002-7863

Keywords:

2009, 2013 and earlier

Abstract:

Several fluorescent macrocycles based on 1,3-butadiyne-bridged dibenz[a,j]anthracene subunits have been synthesized via a multistep
route. The synthetic strategy involved the initial construction of a
functionalized dibenz[a,j]anthracene building block, subsequent
installation of free alkyne groups on one side of the polycyclic aromatic
framework, and a final cyclization based on a modified Glaser coupling
under high-dilution conditions. Photophysical studies on three conjugated
macrocycles revealed the formation of J-aggregates in thin films, as well
as in concentrated solid solutions (polyisobutylene matrix), with peak
absorption and emission wavelength in the range of λ = 460−480 nm. The
characteristic red-shifting of the J-aggregate features as compared to the
monomer spectra, enhancement in absorption intensities, narrowed
linewidths, and minimal Stokes shift values, were all observed. We
demonstrate that improvements in spectral features can be brought about by
annealing the films under a solvent-saturated atmosphere, where for the
best films the luminescence quantum efficiency as high as 92% was
measured. This class of macrocycles represents a new category of
J-aggregates that due to their high peak oscillator strength and high
luminescence efficiency have the potential to be utilized in a variety of
optoelectronic devices.