AN EFFICIENT MIMIC OF CYTOCHROME-P-450 FROM A ZEOLITE ENCAGED IRON COMPLEX IN A POLYMER MEMBRANE

MANY attempts have been made to mimic the catalytic oxidative properti es of the enzyme cytochrome P-450. For homogeneous systems' the mechan isms of oxidation can be readily determined but proper mimicry of the protein environment is difficult to achieve. Heterogeneous mimics have been designed that use organometallic complexes encapsulated in the s upercages of zeolites(2,3), which enables control of selectivity and i nhibition of auto-oxidation. But these systems do not show any mechani stic analogy with the enzymatic process, and the oxidation rates tend to be low. Here we report a composite catalytic system that achieves r ealistic mimicry of cytochrome P-450 as well as catalytic turnover rat es that make the system industrially viable. Our catalyst incorporates iron phthalocyanine complexes encapsulated in crystals of zeolite Y, which are in turn embedded ina polydimethylsiloxane membrane. The poly mer acts as a mimic of the phospholipid membrane in which cytochrome P -450 resides(4), acting as an interface between two immiscible phases and avoiding the need for solvents or phase-transfer agents. This syst em oxidizes alkanes at room temperature at rates comparable to those o f the enzyme(5). The observation of a large kinetic isotope effect and the preferential oxidation of tertiary C-H bonds suggest close mechan istic similarities to the enzymatic process.