Fig. 1: Proof-of-concept autonomous research in fundamental electrochemistry.

a Concept of an autonomous closed-loop process for mechanistic investigation of molecular electrochemistry from cyclic voltammetry (CV). b Annotated photograph and (c) schematic of our constructed autonomous electrochemical platform based on classical electroanalytical setups and installed in an oxygen/moisture-free glovebox. The platform is deployed for mechanistic studies of the reaction of cobalt tetraphenylporphyrin (CoTPP) with a library of organohalide (RX) electrophiles in dimethylformamide (DMF) solvent using tetrabutylammonium hexafluorophosphate (NBu₄PF₆) as the supporting electrolyte. d A prototypical EC mechanism in which a quasi-reversible if not completely reversible reduction of Co^IITPP (E step) yields a nucleophilic Co^ITPP species that attacks the R–X bond and forms a metal–alkyl bond (C step) bearing a characteristic second-order kinetic rate constant (k₀). e Deep-learning (DL) capability that transduces CV features into quantifiable figures-of-merit (mechanism propensity distributions, denoted as y) compatible with downstream Bayesian optimization and automated experimentation. The voltammograms in (e) are adapted from the middle panel in Fig. 2a, where the experimental conditions are detailed. The reverse-to-forward peak current ratio (i_pa/i_pc) between anodic (i_pa) and cathodic (i_pc) peak currents of the Co^II/I redox is defined in Supplementary Note 5. Five prototypical mechanisms (E, EC, CE, ECE, DISP1) in molecular electrochemistry are defined in Supplementary Table 6. f A generally applicable closed-loop workflow designed to explore the parameter space and discern the possible presence of an EC mechanism given a specific RX (Stage I) and, if an EC mechanism is present, to further suggest and identify the desired experimental conditions for the quantification of k₀ value (Stage II).