A tool for deciphering the redox potential ranking of organic compounds: the case study of biomass extracted quinones for sustainable energy
Carbonyl compounds have emerged as promising organic electrodes for sustainable energy storage. Accelerating the process of performant materials discovery relies on the possibility of developing methodologies to enable the scan of various sets of candidates. The genesis of such educated guess strategy has to be privileged to reduce the search space of experiments, accelerate this research area and contribute to the sustainable effort. To address this challenge, we built a quantitative structure-activity relationship to unveil the origin of the redox potential magnitude as a function of both structural features and complexation effects. The potential of this prediction model is demonstrated on various ortho-quinones directly deriving from naturally occurring catechols. Beyond the modulation provided by substituent change, the possibility of calling to various kinds of alkaline(-earth)-ion electrochemistry is examined thoroughly. The power of partitioning the total molecular energy into additive atomic group contributions is highlighted and the built-up of this robust strategy enables a guidance towards rational selection of most suited compound/metal-ion couples. An upshift/downshift of the redox potential by switching from Li to Mg/Na is revealed, while the identification of the relative role played by the various components of the systems as well as electrostatic interactions is clearly identified. These results, particularly the evidence of different substituent effects on the single/double reduction potentials and as a function of type of electrochemistry (Li/Na/Mg), have important implications for designing new electroactive compounds with tailored redox properties.