Synthesis of asymmetric biphenyl derivatives for optoelectronic applications

• Ten compounds with biphenyl as backbone was asymmetrically modified.
• These compounds emit intense pure-blue with high quantum yields up to 80%.
• The cyclic voltammograms are completely reversible.
• These compounds are useful for blue-emitting, hole-transport and host materials.

We report the synthesis and optical properties of a series of ten organic compounds with biphenyl as the backbone and asymmetrically modified by triphenylamines, carbazoles and tetraphenylsilanes (BP 1-10). BP 1-10 were synthesized mainly by Ullmann coupling reaction and Suzuki cross-coupling reaction and characterized by EA, NMR, MS, UV–Vis, DSC, TGA, fluorescence spectra and cyclic voltammetry. They exhibit reversible electrochemical behavior with low oxidation potentials and emit intense pure-blue light with high fluorescence quantum yields (up to 80%). BP 1 was fabricated into multi-layered light-emitting diodes as blue-emitting, host and hole transport materials. Based on the performance of BP 1 and the similarity in chemical structure to those compounds reported in literature, these compounds are expected to be good and versatile hole transport, host and blue emitting materials.