Optical, Electrochemical, and Sensing Properties of Polyfluorenes Bearing Thiazole or Oxazole and Triphenylamine in the Main Chain

Polyfluorenes bearing thiazole (PFTH) or oxazole (PFOX) heterocyclic units as well as triphenylamine (TPA) in the main chain were synthesized. The ratio of thiazole or oxazole/TPA in the polymer chain varies from 100/0 to 25/75. The optical properties of polymers depend on thiazole or oxazole contents. Cyclic voltammetry reveals that thiazole or oxazole hinder the oxidation of polymers and only polymers with TPA show reversible oxidation. The Electron Affinities do not practically depend on composition of the polymer chain. The sensing properties of polymers PFTH100 and PFOX100 are investigated toward several cations and anions. Polymers detect two analytes, Fe2+ and Hg2+. PL quenching shows linear response to Fe2+ in wide concentration region 1-800 mu M. I- anions quench the emission of polymers. Hg2+ turns on the emission of the polymer/I- complex at concentrations as low as 1 mu M. Enhancement of polymer/I- emission exhibits linear response to Hg2+ concentration. PFTH100 is able to detect Fe2+ and H2+ that coexist in a solution. (C) 2016 Wiley Periodicals, Inc.