Mononuclear Iron Complexes with Tetraazadentate Ligands as Water Oxidation Catalysts. Issue 20 (15th June 2016) - Panchbhai, Gayatri
Abstract : Two iron(II) complexes with tetraazadentate ligands have been synthesised, characterised and evaluated as water oxidation catalysts. The two ligands, N, N′ ‐diisopropyl‐ N, N′ ‐bis(2‐pyridylmethyl)‐1, 2‐diaminoethane (1 ), and N ‐methyl‐ N ‐(2‐pyridinylmethyl)‐2, 2′‐bipyridine‐6‐methanamine (2 ), both give iron(II) complexes (1Fe and2Fe, respectively) with an octahedral coordination geometry with two labile triflate ligands in a cis configuration in the crystal structures. When treated with cerium(IV) as a chemical oxidant in aqueous solution at room temperature the complexes form semi‐stable Fe IV (O) species that can be detected in the UV/Visible region. Both1Fe and2Fe can act as catalysts for water oxidation when treated with a large excess of oxidant, but1Fe is a better catalyst than2Fe . Possible geometrical factors behind this difference in reactivity are discussed and compared with literature data. Abstract : Two iron(II) complexes with tetraazadentate ligands are synthesized, characterized and reported as molecular water oxidation catalysts when using cerium(IV) as a chemical oxidant.