Supramolecular Storage and Controlled Photorelease of an Oxidizing Agent using a Bambusuril Macrocycle

The oxidizing ability of peroxodisulfate upon complexation inside the Bambusuril macrocycle cavity is inhibited. This dianionic agent can be released on demand from its stable 1:1 complex in water (log K_a =6.9 m^-1 ) by addition of a more strongly bound anion, such as iodide (log K_a =7.1 m^-1 ), which can also be delivered in situ upon irradiation from a 4-hydroxyphenacyl iodide derivative with spatial and temporal precision. The oxidizing properties of peroxodisulfate ions liberated from the complex recover and can take part in subsequent chemical transformations.