Light‐Switchable Metal Complexes: Introducing Photoresponsive Behaviour Through Azoheteroarenes

Abstract Azoheteroarenes are emerging classes of photoswitches with versatile scaffolds that offer distinct features such as efficient photoisomerization, tunable stability of the photoswitched states, and bidirectional photoswitching. Moreover, the heteroatoms of such photoswitches exhibit coordination ability to bind to the metal centers. The resulting azoheteroarene‐based metal complexes can be designed and developed to tune various metal‐based properties towards intriguing applications such as in optics, magnetic properties, data storage applications, and catalysis. Despite the diverse utility of azopyridines in such contexts, other azoheteroarenes, particularly the state‐of‐the‐art five‐membered heterocycle‐based photoswitches, remain under‐explored. In this Review, we describe the diverse classes of azoheteroarene‐coordinated metal complexes reported in the literature and survey their photoswitching behaviour and applications. Furthermore, we identify potential azoheteroarene candidates for building photochrome‐coupled metal complexes and supramolecular architectures for maximizing the photo‐tuning of metal‐related properties.