A CoII complex for 19F MRI-based detection of reactive oxygen species

A fluorinated, air-stable cobalt(II) complex serves as a turn-on F-19 magnetic resonance imaging (MRI) tracer for reactive oxygen species including H2O2. Upon oxidation with H2O2, the complex converts from paramagnetic high spin Co-II to diamagnetic low spin Co-III resulting in a chemical shift change and enhancement in (19)FNMRsignal. Further, the oxidation can be reversed in the presence of reductant Na2S2O4. The turn-on response is demonstrated by F-19 MRI, characterized by a similar to 2-3 fold enhancement in signal.