Synthesis, photophysics, structure‐tunable photoluminescence, and electrochemical properties of soluble poly(p‐phenylenevinylene)‐based polymers with adjacent 1,3,4‐oxadiazoles in the backbone

Abstract

Three new poly(p‐phenylenevinylene)‐based polymers containing two 1,3,4‐oxadiazole moieties in the main chain per repeat unit were synthesized by Heck coupling. A single, double, or triple bond was introduced between the oxadiazoles to provide a means for modifying the polymer properties. The polymers were readily soluble in common organic solvents and showed Tg values lower than 50 °C. The color of the emissive light in both the solid state and the solution could be tuned by a change in the nature of the bond between the oxadiazole rings. The polymers emitted ultraviolet‐green light in solution with a photoluminescence (PL) emission maximum at 345–483 nm and blue‐green light at 458–542 nm in thin films. The PL quantum yields in solution were 0.36–0.43. The electrochemical properties are affected by the nature of the bond between the oxadiazoles as well. In polymers with a single bond between the oxadiazoles, a lower ionization potential was observed than in polymers with a double or triple bond. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3079–3090, 2005

Coumarin‐containing poly(fluorenediylvinylene)s: Synthesis, photophysics, and electroluminescence

“…A broad, featureless emission band and a very large Stokes shift (165 nm) were observed in CF and are characteristic of excimers or aggregates in the solid state 47, 48. Similar behavior was observed for several PPV‐based polymers as shown in our previous articles,49, 50 but in CF, both the redshift and Stokes shift were much larger. We assume that the pronounced tendency to aggregate in polymer CF was due to the aliphatic chains in fluorene moieties, whereas the double bond in CV could undergo conformation changes that could prevent aggregation.…”

Regulation of hub mRNA stability and translation by miR430 and the dead end protein promotes preferential expression in zebrafish primordial germ cells

“…This feature results in imbalance in charge injection and transport, and thus poor external quantum efficiencies from single‐layer OLEDs 5, 12–14. One of the most efficient way to improve the electron affinity of these polymers is the insertion of electron‐deficient moieties such as CN group,15 1,3,4‐oxadiazole,16–19 quinoxaline,20–22 pyridine,23 and quinoline24 in the conjugated backbone. On the other hand, the incorporation of electron‐rich triphenylamine or carbazole in polymer backbones can lower ionization potential values, and subsequently the energy barrier for hole injection from the anode.…”

Bipolar poly(p‐phenylene vinylene)s bearing electron‐donating triphenylamine or carbazole and electron‐accepting quinoxaline moieties

“…This feature results in imbalance in charge injection and transport, and thus poor external quantum efficiencies from single-layer OLEDs. 5,[12][13][14] One of the most efficient way to improve the electron affinity of these polymers is the insertion of electron-deficient moieties such as CN group, 15 1,3,4-oxadiazole, [16][17][18][19] quinoxaline, [20][21][22] pyridine, 23 and quinoline 24 in the conjugated backbone. On the other hand, the incorporation of electron-rich triphenylamine or carbazole in polymer backbones can lower ionization potential values, and subsequently the energy barrier for hole injection from the anode.…”