10.1021/acs.inorgchem.7b01418.s001 Fang Wang Fang Wang Sabine Becker Sabine Becker Mikael A. Minier Mikael A. Minier Andrei Loas Andrei Loas Megan N. Jackson Megan N. Jackson Stephen J. Lippard Stephen J. Lippard Tuning the Diiron Core Geometry in Carboxylate-Bridged Macrocyclic Model Complexes Affects Their Redox Properties and Supports Oxidation Chemistry American Chemical Society 2017 X-ray diffraction studies methane monooxygenase hydroxylase phenol-imine macrocyclic ligands Diiron Core Geometry Carboxylate-Bridged Macrocyclic Model Complexes Affects Me carboxylate arm controls COOH CH 2 units RNR H 3 PIMICn diiron core geometry presence Fe 2 RCO complex carboxylate-bridged diiron proteins 2017-09-05 18:20:23 Journal contribution https://acs.figshare.com/articles/journal_contribution/Tuning_the_Diiron_Core_Geometry_in_Carboxylate-Bridged_Macrocyclic_Model_Complexes_Affects_Their_Redox_Properties_and_Supports_Oxidation_Chemistry/5378086 We introduce a novel platform to mimic the coordination environment of carboxylate-bridged diiron proteins by tethering a small, dangling internal carboxylate, (CH<sub>2</sub>)<sub><i>n</i></sub>COOH, to phenol-imine macrocyclic ligands (H<sub>3</sub>PIMICn). In the presence of an external bulky carboxylic acid (RCO<sub>2</sub>H), the ligands react with [Fe<sub>2</sub>(Mes)<sub>4</sub>] (Mes = 2,4,6-trimethylphenyl) to afford dinuclear [Fe<sub>2</sub>(PIMICn)­(RCO<sub>2</sub>)­(MeCN)] (<i>n</i> = 4–6) complexes. X-ray diffraction studies revealed structural similarities between these complexes and the reduced diiron active sites of proteins such as Class I ribonucleotide reductase (RNR) R2 and soluble methane monooxygenase hydroxylase. The number of CH<sub>2</sub> units of the internal carboxylate arm controls the diiron core geometry, affecting in turn the anodic peak potential of the complexes. As functional synthetic models, these complexes facilitate the oxidation of C–H bonds in the presence of peroxides and oxo transfer from O<sub>2</sub> to an internal phosphine moiety.