Photostable BF₂-Chelated Fluorophores Based on 2-(2'-Hydroxyphenyl)benzoxazole and 2-(2'-Hydroxyphenyl)benzothiazole

Abstract

Organic chromophores based on small molecules have attrac- ted considerable attention over the past decades due to their potential applications including organic light-emitting diodes (OLEDs), solar cells, dye lasers, photosensitizers and molecular probes. 1 A great variety of organic and organometallic lumine- scent molecules with different chemical/photophysical proper- ties adapted to specific needs have been reported, and a number of those are also commercially available. 2 we report the synthesis and characterization of two new boron complexes, 1 and 2, based on HBO and HBT as potential blue luminescent materials. Boron complexes 1 and 2 were synthesized in one step accor- ding to Scheme 1. Commercially available HBO and HBT were reacted with boron trifluoride etherate (BF3·OEt2) in dichloro- methane at room temperature to give dyes 1 and 2, in 50% and 92% isolated yields. Boron complexes 1 and 2 exhibited good solubility in common organic solvents such as THF, CH2Cl2, CHCl3, toluene, dichloroethane and DMSO. Their structure and purity were confirmed by 1 H and 13 C NMR spectroscopy and HR-MS.