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Flavin Derivatives with Tailored Redox Properties: Synthesis, Characterization, and Electrochemical Behavior
Author(s) -
Kormányos Attila,
Hossain Mohammad S.,
Ghadimkhani Ghazaleh,
Johnson Joe J.,
Janáky Csaba,
de Tacconi Norma R.,
Foss Frank W.,
Paz Yaron,
Rajeshwar Krishnan
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201600207
Subject(s) - flavin group , redox , chemistry , cyclic voltammetry , electrochemistry , molecule , aqueous solution , electron transfer , photochemistry , bulk electrolysis , substituent , electrode , voltammetry , combinatorial chemistry , inorganic chemistry , organic chemistry , enzyme
This study establishes structure–property relationships for four synthetic flavin molecules as bioinspired redox mediators in electro‐ and photocatalysis applications. The studied flavin compounds were disubstituted with polar substituents at the N1 and N3 positions (alloxazine) or at the N3 and N10 positions (isoalloxazines). The electrochemical behavior of one such synthetic flavin analogue was examined in detail in aqueous solutions of varying pH in the range from 1 to 10. Cyclic voltammetry, used in conjunction with hydrodynamic (rotating disk electrode) voltammetry, showed quasi‐reversible behavior consistent with freely diffusing molecules and an overall global 2e − , 2H + proton‐coupled electron transfer scheme. UV/Vis spectroelectrochemical data was also employed to study the pH‐dependent electrochemical behavior of this derivative. Substituent effects on the redox behavior were compared and contrasted for all the four compounds, and visualized within a scatter plot framework to afford comparison with prior knowledge on mostly natural flavins in aqueous media. Finally, a preliminary assessment of one of the synthetic flavins was performed of its electrocatalytic activity toward dioxygen reduction as a prelude to further (quantitative) studies of both freely diffusing and tethered molecules on various electrode surfaces.