Biomaterial Database

Porous metal-organic frameworks for heterogeneous biomimetic catalysis. 2014

Min Zhao, and Sha Ou, and Chuan-De Wu

Center for Chemistry of High-Performance and Novel Materials, Department of Chemistry, Zhejiang University , Hangzhou 310027, P. R. China.

Metalloporphyrins are the active sites in monooxygenases that oxidize a variety of substrates efficiently and under mild conditions. Researchers have developed artificial metalloporphyrins, but these structures have had limited catalytic applications. Homogeneous artificial metalloporphyrins can undergo catalytic deactivation via suicidal self-oxidation, which lowers their catalytic activity and sustainability relative to their counterparts in Nature. Heme molecules in protein scaffolds can maintain high efficiency over numerous catalytic cycles. Therefore, we wondered if immobilizing metalloporphyrin moieties within porous metal-organic frameworks (MOFs) could stabilize these structures and facilitate the molecular recognition of substrates and produce highly efficient biomimetic catalysis. In this Account, we describe our research to develop multifunctional porphyrinic frameworks as highly efficient heterogeneous biomimetic catalysts. Our studies indicate that porous porphyrinic frameworks provide an excellent platform for mimicking the activity of biocatalysts and developing new heterogeneous catalysts that effect new chemical transformations under mild conditions. The porous structures and framework topologies of the porphyrinic frameworks depend on the configurations, coordination donors, and porphyrin metal ions of the metalloporphyrin moieties. To improve the activity of porous porphyrinic frameworks, we have developed a two-step synthesis that introduces the functional polyoxometalates (POMs) into POM-porphyrin hybrid materials. To tune the pore structures and the catalytic properties of porphyrinic frameworks, we have designed metalloporphyrin M-H8OCPP ligands with four m-benzenedicarboxylate moieties, and introduced the secondary auxiliary ligands. The porphyrin metal ions and the secondary functional moieties that are incorporated into porous metal-organic frameworks greatly influence the catalytic properties and activities of porphyrinic frameworks in different reactions, such as the oxidation of alkylbenzenes, olefins, and hexane and the photo-oxygenation of 1,5-dihydroxynaphthalene and sulfides. The porphyrin metal ions and the secondary auxiliary sites in the pores can work together synergistically to enhance the catalytic activities of porphyrinic frameworks. Compared with their homogeneous counterparts, the activities and stabilities of the heterogeneous porphyrinic frameworks are remarkable: the immobilization of metalloporphyrins onto the pore surfaces of MOFs not only prevents their suicidal self-oxidation but also allows them to activate inert substrate molecules, such as cyclohexane. Moreover, because the bulky molecules cannot easily access the active sites inside the pores of porphyrinic frameworks, these porous materials demonstrate interesting size-selective catalytic properties toward substrates.

UI	MeSH Term	Description	Entries
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D008345	Manganese	A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)
D008665	Metalloporphyrins	Porphyrins which are combined with a metal ion. The metal is bound equally to all four nitrogen atoms of the pyrrole rings. They possess characteristic absorption spectra which can be utilized for identification or quantitative estimation of porphyrins and porphyrin-bound compounds.	Metalloporphyrin
D009942	Organometallic Compounds	A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metallo-Organic Compound,Metallo-Organic Compounds,Metalloorganic Compound,Organometallic Compound,Metalloorganic Compounds,Compound, Metallo-Organic,Compound, Metalloorganic,Compound, Organometallic,Compounds, Metallo-Organic,Compounds, Metalloorganic,Compounds, Organometallic,Metallo Organic Compound,Metallo Organic Compounds
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D013499	Surface Properties	Characteristics or attributes of the outer boundaries of objects, including molecules.	Properties, Surface,Property, Surface,Surface Property
D016062	Porosity	Condition of having pores or open spaces. This often refers to bones, bone implants, or bone cements, but can refer to the porous state of any solid substance.	Porosities
D058116	Lewis Acids	Any chemical species which accepts an electron-pair from a LEWIS BASE in a chemical bonding reaction.	Lewis Acid,Acid, Lewis,Acids, Lewis
D060326	Chemistry Techniques, Synthetic	Methods used for the chemical synthesis of compounds. Included under this heading are laboratory methods used to synthesize a variety of chemicals and drugs.	Inorganic Synthesis,Inorganic Synthesis Methods,Inorganic Synthesis Techniques,Methods of Inorganic Synthesis,Methods of Organic Synthesis,Methods of Peptide Synthesis,Organic Synthesis,Organic Synthesis Methods,Organic Synthesis Techniques,Peptide Synthesis Methods,Peptide Synthesis Techniques,Peptide Synthesis, Synthetic,Synthetic Chemistry Techniques,Synthetic Peptide Synthesis,Chemistry Technique, Synthetic,Inorganic Syntheses,Inorganic Synthesis Method,Inorganic Synthesis Technique,Method, Inorganic Synthesis,Method, Organic Synthesis,Method, Peptide Synthesis,Methods, Inorganic Synthesis,Methods, Organic Synthesis,Methods, Peptide Synthesis,Organic Syntheses,Organic Synthesis Technique,Peptide Syntheses, Synthetic,Peptide Synthesis Method,Peptide Synthesis Technique,Syntheses, Inorganic,Syntheses, Organic,Syntheses, Synthetic Peptide,Synthesis Method, Inorganic,Synthesis Method, Peptide,Synthesis Methods, Inorganic,Synthesis Methods, Peptide,Synthesis Technique, Inorganic,Synthesis Technique, Organic,Synthesis Technique, Peptide,Synthesis Techniques, Inorganic,Synthesis Techniques, Organic,Synthesis Techniques, Peptide,Synthesis, Inorganic,Synthesis, Organic,Synthesis, Synthetic Peptide,Synthetic Chemistry Technique,Synthetic Peptide Syntheses,Technique, Inorganic Synthesis,Technique, Organic Synthesis,Technique, Peptide Synthesis,Technique, Synthetic Chemistry,Techniques, Inorganic Synthesis,Techniques, Organic Synthesis,Techniques, Peptide Synthesis,Techniques, Synthetic Chemistry