Kinetic, diameter isotope effects

The most important class of solid-state enzyme mimics is based on zeolites. Zeolites are solid materials composed of Si04 or AIO4 tetrahedra linked at their corners, affording a three-dimensional network with small pores of molecular dimensions. They possess a unique feature of a strictly uniform pore diameter. In particular, zeolites with encapsulated metal complexes are used as inimics of cytochrome P-450.An efficient enzyme mimic was obtained by encapsulating an iron phthalocyanine complex into crystals of zeolite Y, which were, in turn, embedded into a polydimethylsiloxane membrane acting as a mimic of the phospholipid membrane.With t-butylhydroperoxide as the oxidant, the system hydroxyl-ates alkanes at room temperature with rates comparable to those for the enzyme. It shows similar selectivity (preference oxidation of tertiary C-H bonds) and a large kinetic isotope effect of nine. 

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