Among the pathways for improving the practice of photodynamic therapy of cancer, increasing the selectivity of photodynamic action is an obvious choice. Considering the different characteristics of mitochondria in normal cells and cancer cells, we designed mitochondria‐targeting photosensitizers. We now demonstrate for the first time that mitochondria‐targeted photosensitizers by triphenylphosphonium (TPP) derivatization are more selective for cancer cells compared to normal cells, presumably due to the larger membrane potential of cancer‐cell mitochondria allowing more efficient accumulation of the photosensitizer.

Addition of fluoride ions switches on the release of singlet oxygen, by removing a steric stopper.

Singlet oxygen generated by the cycloreversion of endoperoxides has anti-coagulant activity.