Azobenzene-functionalized metal-organic polyhedra for the optically responsive capture and release of guest molecules

Stimuli-responsive metal-organic polyhedra (srMOPs) functionalized with azobenzene showed UV-irradiation-induced isomerization from the insoluble trans-srMOP to the soluble cis-srMOP, whereas irradiation with blue light reversed this process. Guest molecules were trapped and released upon cis-to-trans and trans-to-cis isomerization of the srMOPs, respectively. This study provides a new direction in the ever-diversifying field of MOPs, while laying the groundwork for a new class of optically responsive materials. Lock in the guests, later set them free: Stimuli-responsive metal-organic polyhedra (srMOPs) functionalized with azobenzene showed UV-light-induced isomerization from insoluble srMOPs substituted with trans-azobenzene to soluble srMOPs with cis-azobenzene units; irradiation with blue light reversed this process (see picture). Guest molecules were trapped upon cis-to-trans and released upon trans-to-cis isomerization of the azobenzene units.