A Mononuclear Manganese(II) Complex Demonstrates a Strategy To Simultaneously Image and Treat Oxidative Stress

A manganese(II) complex with a ligand containing an oxidizable quinol group serves as a turn-on sensor for H2O2. Upon oxidation, the relaxivity of the complex in buffered water increases by 0.8 mM–1 s–1, providing a signal that can be detected and quantified by magnetic resonance imaging. The complex also serves as a potent antioxidant, suggesting that this and related complexes have the potential to concurrently visualize and alleviate oxidative stress.