Fusion and planarization of bisBODIPY: a new family of photostable near infrared dyes

We have synthesized a new family of directly-fused bisBODIPY BBP 1 through a key FeCl3-mediated intramolecular oxidative cyclodehydrogenation reaction and its derivatives 2 and 3 from the Knoevenagel reaction. These dyes display effective expansion of π-conjugation over the two BODIPYs due to their locked coplanar conformation, showing intriguing electrochemical and spectroscopic properties, such as intensive absorption/emission bands ranging from 676 to 877 nm and high photostability.