Oxygenation potential of zeolite encapsulated nonheme complexes

3 OXYGENATION POTENTIAL OF ZEOLITE ENCAPSULATED NONHEME COMPLEXES 

Cyclohexane is oxygenated into cyclohexanone as the major product,[94] pointing to the occurrence of Mn-oxo type catalysis. HC1 treatment of the zeolite prior to ion exchange and ligand addition, shows a 4-fold increase in TOF, indicating that creation of mesopores with access to the external crystal rim enhances mass transfer without affecting the specific zeolitic sites needed for complex retention.1951 

Upon addition of stoichiometric amount of bpy to Cu11 exchanged smectite-type montmorillonite, the formation of a Cun(bpy)2 complex was claimed, which was very active and selective for the oxidation of alcohols into the corresponding ketones.[96] Unfortunately, neither the nature of the secondary porosity, the complex geometry nor its location was investigated in further detail. 

An analogous ship-in-bottle complex, [VO(bpy)2]2+-NaY, could be designed starting from a vanadyl exchanged Y zeolite upon bpy addition.[97] Strong spectroscopic proof for the formation of such complex was evident from FT-Raman, FTIR, diffuse reflectance spectroscopy, XPS and EPR as follows  

With alkenes and peroxides room temperature epoxidation can be performed, the selectivity with respect to ring-openend products being dependent on solvent and hydroperoxide nature.[96] With organic peroxides the epoxide selectivity is high, while with HOOH in acetone high diol selectivity is evident with the cis/trans diol isomer ratio at its equilibrium value. 

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Oxygenation potential of zeolite encapsulated nonheme complexes. 220... 

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