Fig. 4: Substrate scope studies and mechanistic insights.

a The generally applicable closed-loop workflow enables autonomous investigation of EC mechanism between CoTPP and a diverse scope of RX substrates amid negative controls and outliers, and the k₀ values of up to 30 substrates toward the electrogenerated Co^ITPP are measured over multiple orders of magnitude. * within the inquired parameter space; ** reacts with the electrogenerated Co^ITPP but does not follow an EC mechanism. b Hammett plot of para-substituted primary benzyl bromide derivatives on the σ scale, where k_X and k_H are the k₀ values of the para-substituted (p-X-PhCH₂Br, denoted as p-X, where X represents a para-substituent) and unsubstituted (PhCH₂Br, denoted as p-H) substrates, respectively. The error bars in (a) and (b) represent the standard deviations of k₀ and log₁₀(k_X/k_H), respectively, for those substrates measured by the closed-loop workflow for multiple replicates. c Additional manual CV experiments, via sequential titration of Cl(CH₂)₃CN with an increasing equivalent (equiv.) relative to Co^IITPP, confirm Cl(CH₂)₃CN as a mechanistic outlier that reacts with Co^ITPP but does not follow an EC mechanism. 1 mM Co^IITPP in DMF using 0.1 M NBu₄PF₆. Data distributions underlying the error bars in (a) and (b) are presented in Source Data file.