INOR 560 |
| The simplicity of the single copper active site of the enzyme galactose oxidase (GOase), which functions by catalyzing the oxidation of primary alcohols to aldehydes while reducing dioxygen to hydrogen peroxide, has inspired efforts to develop small molecule mimics capable of mild and selective alcohol oxidation. To this end, we have investigated the chemistry of a series of metal (Ni, Cu, Zn) complexes of the salen ligand (rac)- N,N'-bis(3,5-di-tert-butylsalicylidene)cyclohexane-1,2-diamine (H2CDB). Oxidation of the neutral MCDB complexes with a variety of one electron oxidants leads to highly colored metal radical complexes in solution; the nature and stability of the radical species has been found to depend on the solvent and counterion present. One of the radical complexes has been characterized in the solid state by X-ray crystallography. The [MCDB•]+ species exhibit spectral features in solution similar to the oxidized form of GOase (GOaseox). In particular, absorptions in the near-infrared (NIR) have been observed, resembling the tyrosinate-tyrosyl intervalence transition elucidated for GOaseox. Comparison of the calculated spectra with experimental data offers insight into the origin of the observed transitions in these small molecule GOase model complexes.
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Radical Metal Complex Chemistry
2:00 PM-4:55 PM, Tuesday, 12 September 2006 Moscone Center -- Room 301, Oral
Division of Inorganic Chemistry |