We recently invented a new class of oxidatively activated MRI imaging probe that comprises complexes of iron that switch from the Fe(II) oxidation state, which is virtually invisible to the MRI scanner, to the corresponding Fe(III), which is conspicuously visible in an MRI scanner. We have been leveraging this technology to image inflammation in organ systems including the kidneys, liver, bowel, and brain, as the inflammatory microenvironment is aberrantly oxidizing relative to normal tissue to the respiratory burst activity of myeloid immune cells. This talk will cover rthe chemistry that we are pursuing to simultaneously improve the detection/ sensitivity and oxidant specificity of this exciting new class of imaging probe.