Synthesis of Luminescent 2-(2′-Hydroxyphenyl)benzoxazole (HBO) Borate Complexes

Complexation of boron trifluoride by a series of electron donor/acceptor substituted 2-(2'-hydroxy phenyl)benzoxazole (HBO) derivatives yields luminescent B(III) complexes with an emission wavelength ranging from 385 to 425 nm in dichloromethane or toluene. Appropriate chemical functionalization of these new dyes allows connection to different photoactive subunits (Boranll, BODIPY), endowing an efficient cascade energy transfer.