Detection of different oxidation states of individual manganese porphyrins during their reaction wit

Abstract

Manganese porphyrins have been extensively investigated as model systems for the natural enzyme cytochrome P450 and as synthetic oxidation catalysts. Here, we report single-molecule studies of the multistep reaction of manganese porphyrins with molecular oxygen at a solid/liquid interface, using a scanning tunnelling microscope (STM) under environmental control. The high lateral resolution of the STM, in combination with its sensitivity to subtle differences in the electronic properties of molecules, allowed the detection of at least four distinct reaction species. Real-space and real-time imaging of reaction dynamics enabled the observation of active sites, immobile on the experimental timescale. Conversions between the different species could be tuned by the composition of the atmosphere (argon, air or oxygen) and the surface bias voltage. By means of extensive comparison of the results to those obtained by analogous solution-based chemistry, we assigned the observed species to the starting compound, reaction intermediates and products. A scanning tunnelling microscope has been used to image multistep chemical reactions at a solid/liquid interface with single-molecule resolution. On reacting Mn(III) porphyrins with either O2 or a single oxygen donor, at least four distinct reaction intermediates and products were detected and their interconversion could be observed in real space and real time.

Cite this article

den Boer, D., Li, M., Habets, T. et al. Detection of different oxidation states of individual manganese porphyrins during their reaction with oxygen at a solid/liquid interface. Nature Chem 5, 621–627 (2013). https://doi.org/10.1038/nchem.1667

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