Biphasic Perchlorate Activation Enabled by a Dinuclear Fe-NHC Complex

Perchlorate, initially perceived as a weakly coordinating counterion rather than a reactive oxidizing reagent due to its kinetic stability, has garnered attention for its potential in microbial systems. In anaerobic conditions, microbes utilize perchlorate as a terminal oxidant for methane oxidation, involving two distinct stages: extraction and release. The biphasic activation process necessitates the collaborative action of multiple enzymes, a phenomenon not extensively explored in artificial systems. To address this, a dinuclear Fe-NHC complex 1 was designed to enable the biphasic activation of perchlorate. Initially, complex 1 extracts the oxidative potential of perchlorate, leading to the formation of Fe(III)-O-Fe(III) complex 2 as the oxidation product. Subsequently, the extracted oxidative potential can be released by photolyzing a mixture of complex 2 and 9,10-dihydroanthracene. Further, an oxidative homocoupling reaction is initiated under anaerobic conditions, achieving the complete biphasic activation of perchlorate using a single artificial catalyst. This work provides new paradigm for constructing biomimetic anaerobic oxidation using kinetically inert high-valent oxygenated acid anions as oxidants.