Zeolite-like metal-organic frameworks as platforms for applications: On metalloporphyrin-based catalysts

by Alkordi M.H., Liu Y., Larsen R.W., Eubank J.F., Eddaoudi M.
Year: 2008 DOI: 10.1021/ja804703w

Extra Information

Journal of the American Chemical Society, 130 (38), 2008, 12639-12641

Abstract

The extra-large cavities of zeolite-like metal-organic frameworks (ZMOFs) offer great potential for their exploration in applications pertinent to larger molecules, like porphyrins. The anionic nature of the framework allowed for facile in situ encapsulation of a cationic free-base porphyrin, and the α-cage of our (In-imidazoledicarboxylate)-based rho-ZMOF is ideally suited to the isolation of one porphyrin molecule per cage, which prevents the oxidative self-degradation associated with self-dimerization common in homogeneous catalysis and upon aggregation in solid supports like mesoporous silicates or polymers. The encapsulation of a free-base porphyrin [5,10,15,20-tetrakis(1-methyl-4- pyridinio)porphyrin] and the stability of the rho-ZMOF to metalation conditions, allows for the preparation of a variety of metalloporphyrins (i.e., Mn, Cu, Co, Zn ions) with the ZMOF serving as a platform. The Mn-metallated porphyrin encapsulated in rho-ZMOF shows catalytic activity toward the oxidation of cyclohexane, with turn-over numbers, to the best of our knowledge, higher than reported for similar heterogeneous systems, and our system can be recycled up to 11 cycles, which represents a longer lifetime than reported for any other system
 

Keywords

Carbon dioxide Cation cyclohexanol cyclohexanone metalloporphyrin methanol organic compound surfactant Zeolite Article Catalysis catalyst chemical composition Chemical structure crystallization Degradation dimerization electricity