A Supramolecular Enzyme Mimic That Catalyzes the 15,15′ Double Bond Scission of ,-Carotene

Two Ru-porphyrin-linked β-cyclodextrin units form the supramolecular system, which as an enzyme mimic for β,β-carotene 15,15′-dioxgenase binds two substrates of the enzyme with Ka>106 M−1 and selectively catalyzes the cleavage of the central carotinoid bond in the presence of tert-butylhydroperoxide (see picture). Mechanistic aspects of this unusual cleavage of E-configured, conjugated double bonds are discussed.