An All-Inorganic, Polyoxometalate-Based Catechol Dioxygenase That Exhibits >100 000 Catalytic Turnovers

Following a critical analysis of the dioxygenase literature and injection of the insights therein into the development of new dioxygenase catalysts, two new, of four total exemplary, polyoxoanion precatalysts have been synthesized, characterized, and then discovered to exhibit record catalytic lifetime 3,5-di-tert-butylcatechol (DTBC; 1) dioxygenase activity using molecular oxygen as the terminal oxidant. A total of 24 additional polyoxoanion and other precatalysts have also been surveyed for their DTBC dioxygenase activity. The four exemplary precatalyst complexes are the trivanadium(V)-containing, orange-red parent polyoxoanions (n-Bu4N)7[SiW9V3O40], I, and (n-Bu4N)9[P2W15V3O62], II, and their previously unknown polyoxoanion-supported, dark green iron complexes (n-Bu4N)5[(CH3CN)xFe·SiW9V3O40], III, and (n-Bu4N)5[(CH3CN)xFe·P2W15V3O62], IV. Careful, high (95 ± 5%) mass balance studies are reported, studies rare in the dioxygenase literature, but studies made possible in the case of I−IV by their high act...