Electrochemical and computational studies of some 9,10-anthraquinone derivatives in acetonitrile solution

The electrochemical behavior of some recently synthesized 9,10-anthraquinone derivatives on Au electrode in acetonitrile was investigated. In the absence of proton donors, the anthraquinones reduced in two successive one-electron steps. The first step is reversible or nearly reversible, while the second step is quasi-reversible. The influence of molecular structure on the reduction potential is addressed. The diffusion coefficients of the anthraquinone derivatives were determined from chronoamperometry and rotating disk electrode measurements. The heterogeneous electron transfer rate constants and charge transfer coefficients were evaluated from rotating disk voltammetry measurements. An ab-initio quantum mechanical method was carried out at the DFT-B3LYP level to compute the electrode's formal potentials for the four anthraquinones AQ1-AQ4 in acetonitrile solution. A nice linear relationship was observed between the theoretically predicted values and experimentally determined formal electrode potentials of the 9,10-anthraquinone derivatives.