Highly emissive conjugated polymer excimers.

TitleHighly emissive conjugated polymer excimers.
Publication TypeJournal Article
Year of Publication2005
AuthorsKim, Y, Bouffard, J, Kooi, SE, Swager, TM
JournalJournal of the American Chemical Society
Date Publishedoct
Keywordspentiptycene quinone ring polyphenyleneethynylene excimer mediation emission tailoring, polyphenyleneethynylene prepn excimer mediation pendant ring structure

Conjugated polymers often display a decrease of fluorescence efficiency upon aggregation due in large part to enhanced interpolymer interactions that produce weakly emissive species generally described as having excimer-like character. We have found that poly(phenylene ethynylene)s with fused pendant [2.2.2] ring structures having alkene bridges substituted with two ester groups function to give highly emissive, broad, and red-shifted emission spectra in the solid state. To best understand the origin of this new solid-state emissive species, we have performed photophysical studies of a series of different materials in solution, spin-coated thin films, solid solutions, and Langmuir films. We conclude that the new, red-shifted, emissive species originate from excimers produced by interchain interactions being mediated by the particular [2.2.2] ring system employed. The ability to design structures that can reliably produce highly emissive conjugated polymer excimers offers new opportunities in the emission tailoring of electroluminescence and sensory devices.