Observation of intermediates by online mass spectrometry to demonstrate the multiple mechanisms of dye-sensitized photocatalysis†

Online mass spectrometry was applied to reveal multiple mechanisms of visible-light irradiated dye-sensitized photocatalysis for o-phenylenediamine oxidation. The reactants, products and short-lived intermediates were recorded and dynamically tracked. Dimer and unexpected trimer intermediates were observed to deduce the stepwise aerobic photooxidation mechanism with multiple routes, which was supported by theoretical calculations.

Automated summary

Online mass spectrometry was used to investigate the mechanisms of visible-light irradiated dye-sensitized photocatalysis for o-phenylenediamine oxidation, revealing dimer and unexpected trimer intermediates. The stepwise aerobic photooxidation mechanism with multiple routes was deduced with support from theoretical calculations.