Conformationally Restricted Aza‐BODIPY: Highly Fluorescent, Stable Near‐Infrared Absorbing Dyes

Abstract Novel NIR fluorescent, conformational restricted aza‐dipyrromethene boron difluoride (aza‐BODIPY) dyes were prepared by an efficient process. Such conformational restricted aza‐BODIPY dyes possess intense absorption, strong fluorescence, high chemical and photostability. Additionally, the sharp fluorescence of non‐amine containing aza‐BODIPY dyes is insensitive to solvent polarity.