Photoswitching Lanthanoid Luminescence With Diazocines

Abstract The unique photophysical properties of the lanthanoids provide the core functionality for various high‐tech applications, including optoelectronic materials, lasers, anti‐counterfeiting dyes, or tools for biological sciences. The combination of these luminophores with photoswitches has the potential to make them remote controllable and adds new layers of complexity to their applications. We herein report that such a photomodulation of Eu III , Tb III , and Yb III luminescence is possible with the aid of diazocine photoswitches. The new approach, which does not require covalent connection of the photoswitch and antenna ligand, is by design suitable for multiplexing applications and allows for a drastic and reversible modulation of the overall luminescence intensity and luminescence lifetimes. Photophysical studies under bypassing of the antenna ligand and at 77 K gave insights into the mechanism of the effect.