pH‐Switchable Through‐Space Interaction of Organic Radicals within a Self‐Assembled Coordination Cage

Twinned spins yield triplets: The through-space interaction of non-associative stable organic radicals within a self-assembled coordination cage (see scheme) is controlled by pH. The amino group of the radical can be protonated, and the affinity of the radicals for the host consequently decreases at low pH owing to coulombic repulsion. This leads to their release, as observed by ESR spectroscopy.