Harnessing reductive BF 2 -complexation via Ru(II)-catalyzed N-O cleavage of isoxazoles.

Developed here is a highly fluorescent organic N,O bidentate BF 2 complex from isoxazole in the presence of a Ru(II) catalyst. Herein, the complexation proceeds via a selective N-O cleavage of the isoxazole ring. The complex shows absorption ( λ max,abs ) in the range of 352-363 nm with an extinction coefficient ( ε ) in the range of 8000-64 000 M -1 cm -1 , and fluorescence emission ( λ max,em ) in the range of 413-485 nm with a Stokes shift of 61-125 nm having quantum yield up to 33%. Apart from the solution state, the solid BF 2 complex 2u exhibits absorption at 405 nm and strong fluorescence emission at 550 nm with a quantum yield of 26.9%.