Synthesis and characterization of aromatic poly( 1,3,5-triazine-ether)s for electroluminescent devices

Various difluoro functionalized aromatic 1,3,5-triazine monomers were prepared. A series of poly(1,3,5-triazine-ether)s was synthesized by polycondensation with 4,4'-hexafluoroisopropylidenebis[phenol]. The polymers have excellent thermal stability and are amorphous with glass transition temperatures in the range 190-250 degrees C. In order to examine the potential application these polymers may possess for use in organic electroluminescent devices, the redox properties were studied by cyclic voltammetry. It was found that the monomers have high electron affinities and reach LUMO values in the range of -2.7 to -3.1 eV. This opens the possibility to utilize 1,3,5-triazine-containing materials as electron injecting/hole blocking layer in LEDs. Initial LED results are in accordance with these high electron affinities.