Macrocycles, metal, zeolite-encapsulated

There are a few examples of 02 oxidations catalyzed by zeolite-encapsulated complexes. Encapsulated CoPc was active in the oxidation of propene to aldehyde, whereas the free complex was inactive.76 A triple catalytic system, Pd(OAc)2, benzoquinone, and a metal macrocycle, was used to oxidize alk-enes with molecular oxygen at room temperature.77,78 Zeolite-encapsulated FePc79-81 and CoSalophen80,82 complexes were used as oxygen-activating catalysts. 

Metal macrocycles encapsulated in zeolites can be synthesized in different ways.50-53 The flexible ligand51 or intrazeolite complexation53 method involves the diffusion of a ligand into the pores of a metal-exchanged zeolite, where upon complexation with the metal ion, it becomes too large to exit. This... 

Aerobic oxidations on metal macrocycles encapsulated in zeolites... 

Metal macrocycles encapsulated in zeolites seem to be a solution to overcome the above mentioned problem because they combine successfully the advantages of homogeneous catalysts, especially their selectivity and controllability, with the ease of the separation of heterogeneous catalysts. In these catalysts the large, electroneutral metal macrocycle species is held in the zeolite cavities topologically rather than chemically. 

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