Impacts of intramolecular B-N coordination on photoluminescence, electronic structure and electroluminescence of tetraphenylethene-based luminogens

N,C-Chelate four-coordinate organoborons are a new class of luminogenic materials but the impacts of intramolecular B N coordination on the optoelectronic properties of the luminogens are not fully understood. In this work, B N coordination is grafted onto two tetraphenylethene (TPE)-based luminogens and the thermal stabilities, optical properties and electronic structures of the generated organoborons are investigated and compared with those of counterparts without B N coordination. Both luminogens are thermally stable and show aggregation-induced emission. The presence of B N coordination not only improves photoluminescent property of the luminogens, affording excellent solid-state fluorescence quantum yields up to unity, but also lowers the LUMO energy levels, owing to p(pi)-pi* conjugation. The application of both organoborons as emitters for organic light-emitting diodes is evaluated. The devices of them exhibit superior electroluminescent efficiencies to the devices of counterparts, demonstrating that B N coordination is conducive to electroluminescent property of the luminogens. (C) 2013 Elsevier Ltd. All rights reserved.