Well-defined [3,3′]bicarbazolyl-based electroactive compounds for optoelectronics

Well-defined electroactive compounds were synthesized from 9H,9′H-[3,3′]bicarbazolyl and different halo-substituted arylamines by the modified Ullmann coupling reaction. Photophysical properties of dilute solutions of the derivatives were investigated in detail. The new materials were found to constitute glasses with glass transition temperatures ranging from 34 to 130 °C as characterized by differential scanning calorimetry. The compounds possess good solubility in common organic solvents and high thermal stability with 5% weight loss temperatures of 359–440 °C. The electron photoemission spectra for amorphous layers of the compounds have been recorded and the ionization potentials of 5.23–5.47 eV have been established. Room temperature hole drift mobility in the layers of some compounds molecularly dispersed in polymeric host exceed 10−5 cm2/V s at an electric field of 106 V/cm.