Aryl-Substituted Poly p-Phenylene Vinylenes

The same group recently reported that the TBB defects can be brought below the nuclear magnetic resonance (NMR) detection limit by employing similar polymerization conditions (i-BuOK in THF at room temperature) in the synthesis of naphthyl-substituted PPVs 51-53 [112]. Although the absorption and PL spectra of all three polymers are similar, the EL can be finely tuned between 486 nm (for 52) and 542 nm (for 53). The external QE (studied for ITO/PEDOT/polymer/Ba/Al device) is also sensitive to the substituents pattern in the naphthyl pendant group 0.08% for 51, 0.02% for 52, and 0.54% for 53. 

MEH-PPV 13, which raises the HOMO and also unexpectedly brings down the LUMO level of the copolymer (see Section 2.2.3) (Chart 2.10). 

An important extension to phenyl-substituted PPVs was first reported by Tsutsui and coworkers [115], who used Gilch polymerization to synthesize fluorenyl-substituted PPVs (57,58,59) and studied their performance in PLEDs (Chart 2.11). Due to bulky but rigid fluorene substituents, these polymers have excellent solubility and yet are thermally stable up to 320°C and have a 

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