An Azobenzene‐Functionalized Zinc(II) Coordination Complex as a Robust Photoswitch

This study presents the synthesis and photochemical characterization of a novel azobenzene‐appended tripicolylamine ligand and its corresponding zinc complex. The ligand was prepared through a five‐step synthetic route and successfully metalated with zinc(II) acetate and zinc(II) triflate. Photoisomerization studies revealed that the ligand and zinc complex achieve ~85% trans‐to‐cis conversion with 370 nm irradiation while maintaining excellent reversibility across multiple switching cycles. As expected, thermal back‐isomerization kinetics follow first‐order behavior with half‐lives of 50 and 59 h for the ligand and complex, respectively. Coordination to Zn(II) preserves the photoswitching characteristics of the free ligand, providing a well‐defined model platform for studying photoresponsive coordination chemistry.