π-Conjugated Polymers Exhibiting a Novel Doping Based on Redox of Side Chains
摘要:
Novel polyphenylene and polythiophene derivatives that have N,N'-diphenyl-1,4-phenylene-diamine (PDA) units were synthesized using the palladium-catalyzed Suzuki coupling or cross coupling. Each obtained polymer has good redox activity, and the polyphenylene derivatives have two redox couples in acetonitrile that contain 1 M trifluoroacetric acid, whereas the polythiophene derivatives show only one redox couple under the same conditions. The electronic conductivity of the polythiophene derivatives was dramatically enhanced (0.1 S/cm) by the one-electron oxidation of the PDA unit (0.4 V, vs Ag/Ag+), because of the injection of a radical cation into the main chain from the PDA unit. Spectroelectrochemistry showed that the radical cation of the thiophene-substituted PDA was more delocalized than the phenylene-substituted unit. Electrochemical analysis of the model compounds revealed that the injection of radical monocation radical carriers into the main chain is based on electron communication between the intramolecular PDAs.
Novel polyphenylene and polythiophene derivatives that have N,N'-diphenyl-1,4-phenylene-diamine (PDA) units were synthesized using the palladium-catalyzed Suzuki coupling or cross coupling. Each obtained polymer has good redox activity, and the polyphenylene derivatives have two redox couples in acetonitrile that contain 1 M trifluoroacetric acid, whereas the polythiophene derivatives show only one redox couple under the same conditions. The electronic conductivity of the polythiophene derivatives was dramatically enhanced (0.1 S/cm) by the one-electron oxidation of the PDA unit (0.4 V, vs Ag/Ag+), because of the injection of a radical cation into the main chain from the PDA unit. Spectroelectrochemistry showed that the radical cation of the thiophene-substituted PDA was more delocalized than the phenylene-substituted unit. Electrochemical analysis of the model compounds revealed that the injection of radical monocation radical carriers into the main chain is based on electron communication between the intramolecular PDAs.