Official websites use. Share sensitive information only on official, secure websites. Corresponding Authors: Kenneth D. The latter is the first reported cupric superoxide with an experimentally proven Cu—S bond which also possesses demonstrated hydrogen atom abstraction HAA reactivity.
The former has a MetHis 2 coordination sphere and is thought to play the major role in O 2 activation and substrate-binding, while the latter has His 3 coordination and behaves as an electron relay.
In fact, this Met has proven critical to turnover, as mutants lacking sulfur ligation Met, Cys have been inactive. The criticality of the methionine remains unexplained 16 — 19 prompting model system investigations. These have demonstrated the influences of denticity, 4 , 20 — 25 electron richness, 26 , 27 steric modulation, 28 , 29 coordination geometry, 30 temperature, solvent, 31 and hydrogen bonding 32 , 33 on electronic structure and reactivity.
Although thioether-containing tridentate or tetradentate ligand-copper models have been investigated, 34 — 41 many synthetic attempts rather form binuclear cupric peroxides, 37 , 42 — 44 and none exhibit substrate oxidative reactivity.
Furthermore, the extreme instability of this complex prevented rigorous spectroscopic and reactivity studies, as it rapidly formed the more stable trans -peroxide. This four-coordinate, distorted trigonal pyramidal geometry presents an open fifth coordination site for further ligand binding.
