Tuning the Photophysical and Electroluminescence Properties in Asymmetrically Tetrasubstituted Bipolar Carbazoles by Functional Group Disposition.

Carbazoles decorated with both donor and acceptor fragments offer a classical way to optimize bipolar functional properties. In this work, a series of carbazoles featuring triphenylamine donors and cyano acceptors are synthesized and their structure-property relationship is studied. The effects of connectivity and the chromophore number density on photophysical and electroluminescence properties are investigated.

Fine-Tuning of Photophysical and Electroluminescence Properties of Benzothiadiazole-Based Emitters by Methyl Substitution.

New benzothiadiazole-based materials containing methyl substitution are prepared and characterized as promising green/yellowish green emitters for electroluminescent applications. The dyes exhibited shorter wavelength absorption and emission when compared to nonmethylated dyes. A dye containing methyl group on the donor side exhibited blue shift in absorption and emission when compared to the analogous dye containing methyl group away from donor.