Exploration and Synthesis of Fluorescent Oxadiazole and Thiadiazole Boronyls

Abstract

In the last decade, OLEDs have become increasingly ubiquitous in the market, already available in top-range monitors, televisions, and mobile phones. With the push for cheaper devices, much research has focused on finding new dopants to be used in these displays. Simple azole-based organoboron dyes have shown promise in this application, and our lab has investigated tetra-coordinated boron complexes of the oxadiazole and thiadiazole family. These ligands were chosen for their excellent electron transport capability and ability to make use of boron’s unique capability to form B(N,O)X type complexes. Our investigation focused on limiting the rotational sources of internal quenching, and some evidence suggests a notable bathochromic shift when chelated to with BPh2 while chelation to BF2 showed signs of a hypsochromic shift. Unfortunately, a lack of suitable instrumentation forced an end to the exploration of thiadiazole complexes. The onset of COVID-19 further stymied compound characterization, though NMR and limited fluorescence spectroscopic data on BPh2(ODP) was collected.