Fluorescence Studies of Poly(p-phenyleneethynylene)s: The Effect of Anthracene Substitution.

TitleFluorescence Studies of Poly(p-phenyleneethynylene)s: The Effect of Anthracene Substitution.
Publication TypeJournal Article
Year of Publication1995
AuthorsSwager, TM, Gil, CJ, Wrighton, MS
JournalJournal of Physical Chemistry
Keywordsfluorescence polyphenyleneethynylene anthracene substituent effect

The poly(p-phenyleneethynylene) mols. synthesized by a Pd-catalyzed cross-coupling reaction of diiodobenzene derivs. and derivs. of 1,4-diethynylbenzene, are highly luminescent materials. The polymers are sol. by virtue of the -OC16H33 groups introduced on the arom. rings and by controlling their mol. wt. The fluorescent quantum yields are between 0.35 and 0.40 depending on the material. The excited-state lifetimes of the polymers are 1-2 ns, slightly shorter than that of the model compd. 1,4-diphenylethynyl-2,5-dibutoxybenzene, which has a lifetime of 3 ns. Incorporation of anthracene, coupled at the 9,10-positions by using 9,10-dibromoanthracene, into the polymer backbone decreases the quantum yield to between 0.05 and 0.27 depending on the anthracene content. In addn., low-energy electronic transitions and lower wavelength emission bands assocd. with the anthracene group are produced. The polymers harvest optical energy and transfer it to the anthracene resulting in emission from this chromophore. In the case where only terminal anthracene units, introduced by using 9-bromo-10-phenylethynylanthracene, are present, the process is very efficient with >95% of the energy being transferred to the end groups. [on SciFinder(R)]