Electrochemical behavior of chlorophylls, bacteriochlorophylls, and related macrostructures—a review

This review discusses the electrochemical behavior of chlorophylls and bacteriochlorophylls as individual molecules, as well as their complexes, like reaction centers and photosystems I and II. The first part is devoted to describing chlorophylls and bacteriochlorophylls structures, and oxidation and reduction processes on various electrode materials in various solvents. The dependence of number, positions, and reversibility of the observed redox peaks on the solvent composition and aggregation is also discussed. The following part is aimed at reaction centers and photosystems naturally occurring in living organisms. Attention is paid to proper electrode modification, orientation of the studied systems on the electrode surface and reproducibility of the observed phenomena. The differences in electrochemical behavior at metallic and graphitic electrodes are discussed. In the last part, possible future opportunities are pronounced, like modern electrode materials, in situ studies and extension of the redox studies to the reaction centers and photosystems from other organisms.

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