Y. Eichen et al., EFFECT OF PROTONATION-DEPROTONATION PROCESSES ON THE ELECTROOPTICAL PROPERTIES OF BIPYRIDINE-CONTAINING POLY(P-PHENYLENE-VINYLENE) DERIVATIVES, Journal of the American Chemical Society, 120(40), 1998, pp. 10463-10470
New electroluminescent, PPV-like, conjugated polymers containing bipyr
idylene-vinylene subunits were prepared and characterized with respect
to their electrooptical properties. The polymers were found to exhibi
t reversible and tunable optical properties depending on protonation-d
eprotonation processes. pH sensitivity and reversible tunability of th
e polymers were observed by photo- and electroluminescence, optical ab
sorption, photoinduced-absorption, and electroabsorption experiments.
A luminescence red-shift of as much as 0.2 eV (similar to 60 nm) was o
bserved upon full protonation of a flee-base film. Films of the free-b
ase form of the new polymers showed, in general, sharper spectra than
the corresponding protonated films, probably due to increased disorder
and stronger interchain interactions in the latter.