Conjugated Polymers with Geminal Trifluoromethyl Substituents Derived from Hexafluoroacetone

Convenient syntheses of 9,9-bis(trifluoromethyl)fluorene and 6,6,12,12-tetrakis(trifluoromethyl)indenofluorene are reported. The monomers were readily prepd. in two steps from simple halo-aroms. and hexafluoroacetone, which serves as the source of the geminal trifluoromethyl groups. Iodination yields polymerizable monomers that were used to prep. several conjugated polymers. The photophys. properties of these polymers are reported. The polymers demonstrate slightly blue-shifted UV-vis absorption and fluorescence emission spectra and high soln. and solid-state fluorescence quantum efficiency. Polymer photobleaching expts. reveal that poly(fluorene)s with geminal trifluoromethyl substituents demonstrate greater photooxidative stability than poly(9,9-dioctylfluorene). [on SciFinder(R)]