AROMATIC POLYETHERS WITH 1,3,5-TRIAZINE UNITS AS HOLE BLOCKING ELECTRON-TRANSPORT MATERIALS IN LEDS

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'-(hexafluoroisopropylidene)diphenol. The pol ymers have excellent thermal stability and are amorphous with glass tr ansition temperatures in the range of 190-250 degrees C. In order to e xamine the potential to apply these polymers in organic electrolumines cent devices, the redox properties were studied by cyclic voltammetry. It was found that the monomers have high electron affinity and reach LUMO values in the range of -2.7 to -3.1 eV. This opens the possibilit y to utilize 1,3,5-triazine containing materials as electron injecting /hole blocking layer in LEDs. First LED results are in accordance to t hese high electron affinities.