An Autocatalytic System of Photooxidation-Driven Substitution Reactions on a Fe(II)4L6 Cage Framework

The functions of life are accomplished by systems exhibiting nonlinear kinetics: autocatalysis, in particular, is integral to the signal amplification that allows for biological information processing. Novel synthetic autocatalytic systems provide a foundation for the design of artificial chemical networks capable of carrying out complex functions. Here we report a set of Fe(II)4L6 cages containing BODIPY chromophores having tuneable photosensitizing properties. Electron-rich anilines were observed to displace electron-deficient anilines at the dynamic-covalent imine bonds of these cages. When iodoaniline residues were incorporated, heavy-atom effects led to enhanced (1)O2 production. The incorporation of (methylthio)aniline residues into a cage allowed for the design of an autocatalytic system: oxidation of the methylthio groups into sulfoxides make them electron-deficient and allows their displacement by iodoanilines, generating a better photocatalyst and accelerating the reaction.