Mimicking the Regulation Step of Fe-Monooxygenases: Allosteric Modulation of Fe -Oxo Formation by Guest Binding in a Dinuclear Zn -Fe Calix[6]arene-Based Funnel Complex.

A heteroditopic ligand associated with a calix[6]arene scaffold bearing a tris(imidazole) coordinating site at its small rim and an amine/pyridine ligand at its large rim has been prepared, and its regioselective coordination to Zn at the small rim and Fe in the amine/pyridine ligand has been achieved. The heterodinuclear complex obtained displays an overall cone conformation capped by the tris(imidazole)Zn moiety and bears a non-heme Fe complex at its base. Each of the metal centers exhibits one labile position, allowing the coordination inside the cavity of a guest alkylamine at Zn and the generation of reaction intermediates (Fe (OOH) and Fe O) at the large rim.