Lytic polysaccharide monooxygenase (LPMO) metalloenzymes activate strong C─H bonds (~100 kcal/mol) of polysaccharides such as cellulose. Nature has evolved the ability to perform these thermodynamically difficult processes within LPMO using an active site composed of a single copper ion coordinated to the protein in a T-shaped geometry referred to as the histidine brace. Inspiration from LPMOs has led to the development of synthetic systems to perform multi-electron chemistry using copper complexes. Toward this goal, a four-coordinate Cu(II) aqua complex with a redox-active ligand, (ibaps)3─, has been developed and investigated. The [Cu(II)(ibaps)(OH2)]─ complex exhibits two reversible oxidation events, both of which have been chemically accessed. Deprotonation of the aqua ligand to give the analogous hydroxido compound has also been pursued at each oxidation level. Reactivity of the oxidized hydroxide complexes has been explored with organic substrates.
Thursday, November 12, 2020 - 3:30pm