ABSTRACT
The application of organoboron compounds as light-absorbing or light-emitting species in areas as relevant as organic electronics or biomedicine has motivated the search for new materials which contribute to the progress of those applications. This article reports the synthesis of four-coordinate boron complexes based on the unexplored 7-(azaheteroaryl)indole ligands. An easy synthetic approach has enabled the fine-tuning of the electronic structure of the organoboron species by modifying a heteroaromatic component in the conjugated system. Furthermore, a comprehensive characterization by X-ray diffraction, absorption and emission spectroscopy, both in solution and in the solid state, cyclic voltammetry, and computational methods has evidenced the utility of this simple strategy. Large Stokes shifts have been achieved in solid thin-films which show a range of emitted light from blue to orange. The synthesized compounds have been used as biocompatible fluorophores in cell bioimaging.
ABSTRACT
A novel class of π-conjugated systems, which combine the indolo[3,2-b]carbazole unit with the formation of four-coordinate boron complexes, is presented. The resulting conjugated compounds have a double-laddered structure that provides interesting optical and electrochemical properties. The wide absorption range, covering most of the visible spectrum, along with the narrowing of the HOMO-LUMO energy gap, due to the presence of diphenylboryl centers, reinforces the potential of these molecules within the area of organic electronics.
