Synthesis and Studies of BODIPY-Ferrocene Conjugates: An Overview.

Boron(III) difluoro dipyrromethene (BODIPY) dyes are known for their strong absorption, high fluorescence quantum yields, narrow emission bands, and high photostability. These properties make them suitable for sensing, imaging, and therapeutic applications. The incorporation of the redox-active ferrocene unit into the BODIPY framework yields donor-acceptor hybrid systems with fascinating electronic and photophysical properties. In these systems, photoinduced electron transfer often triggers fluorescence quenching and facilitates reversible electrochemical control of excited states. Structural modification of the BODIPY core, particularly through the incorporation of π-conjugated linkers (e.g., C═C and C≡C bonds) at the meso- and pyrrolic positions, extends the conjugation. These modifications enhance electronic communication between donor ferrocene and acceptor BODIPY and allow the incorporation of auxiliary units like porphyrin, pyrene, fullerene, and biotin. This review highlights recent advances in the synthesis of BODIPY-ferrocene conjugates using Sonogashira coupling, Knoevenagel condensation, and click chemistry. Their spectroscopic, electrochemical, and computational investigations are also described, including their tunable photophysical, redox properties, and prospective applications in sensors, molecular switches, and optoelectronic materials.