Derivatized quinone: Potential electrodes for ionic batteries - A quantum chemical study

The present study explored the effect of the replacement of single to all four Hs by electronegative F group in the structure and the respective electrochemical properties of 1,4-benzoquinone (1,4-BQ or BQ) using theoretical techniques. The considered BQ derivatives in its neutral and anionic states were optimized at PBE/6–311+G(d,p) level of theory in gas and solvent phases using density functional theory technique. The solvation free energy calculations were computed using C-PCM (Conductor like Polarizable Continuum Model) solvation model to approximate the solvation contributions to the free energies. The calculated Gibbs free energy was found to be more negative for fluorine substituted quinone derivatives than bare 1,4-BQ and much more negative values were obtained in solvent phase than in gas phase. The calculated redox potential was in the range between 2.43V to 3.29V and increased with the fluorine substitution and was found to be larger for BQ with 3 fluorine substituents. The obtained results added significance to the present study which emphasized the effect of substitution at different position and number to tailor the redox properties of quinone molecules. Thus, in general, the fluorine substituted BQ derivatives might act as potential cathodes for ion batteries