Microporous and mesoporous materials vol:21 issue:4-6 pages:475-486
Biomimetic oxygen activation on binuclear iron active sites occluded within the voids of mesoporous oxides such as HMS (hexagonal mesoporous silica) is an interesting new held of research. As guests, binuclear iron(III) complexes were chosen. Heptapodate N,N,N',N'-tetrakis (2-R methyl)-2-hydroxy-1,3-diaminopropane ligands in which R is either a pyridyl or a benzimidazole group allow metal coordination as in methane mono-oxygenase active sites. The physicochemical characterization with SEM, TGA and sorption analysis shows the interactions of the complexes with the support. IR, Raman and diffuse reflectance-W-Vis-NIR spectroscopy is used to monitor interaction of oxygen (O-16(2) and O-18(2)) Or peroxides with the supported active sites. The cyclohexane, cyclohexylhydroperoxide and isobutane oxidation is described and the mono- and binuclear mechanisms that are occurring in nucleophilic and electrophilic activation pathways are discussed. (C) 1998 Elsevier Science B.V. All rights reserved.