نتایج جستجو برای: metalloporphyrin

تعداد نتایج: 401  

2004
Chen-Yu Yeh Shu-Hua Cheng

Two types of porphyrin free base, meso-tetra(4-vinylphenyl)porphyrin and meso-tetra(4-stilbenyl)porphyrin, were synthesized and characterized. Metallation was achieved by insertion of MnCl24H2O. Oxidative electropolymerization of the manganese porphyrin monomers by cyclic scans would anchor the resulting materials on glassy carbon electrodes. It was found that both poly (manganese tetra(4-vinyl...

Journal: :Molecules 2018
Mário M Q Simões Daniel T G Gonzaga Mariana F C Cardoso Luana da S M Forezi Ana T P C Gomes Fernando de C da Silva Vítor F Ferreira Maria G P M S Neves José A S Cavaleiro

Carbene transfer reactions are very important transformations in organic synthesis, allowing the generation of structurally challenging products by catalysed cyclopropanation, cyclopropenation, carbene C-H, N-H, O-H, S-H, and Si-H insertion, and olefination of carbonyl compounds. In particular, chiral and achiral metalloporphyrins have been successfully explored as biomimetic catalysts for thes...

Journal: :Journal of the American Chemical Society 2009
Abraham M Shultz Omar K Farha Joseph T Hupp SonBinh T Nguyen

Through the use of the tetratopic ligand 1,2,4,5-tetrakis(4-carboxyphenyl)benzene as a key building block, a permanently microporous metal-organic framework with Lewis acidic (porphyrin)Zn struts, ZnPO-MOF, can be made in high yields. ZnPO-MOF can efficiently catalyze acyl-transfer reactions primarily by preconcentrating the substrates within its pores, in stark contrast to analogous supramolec...

Journal: :Symmetry 2014
Gérard Simonneaux Hassan Srour Paul Le Maux Soizic Chevance Daniel Carrie

Symmetry plays a fundamental role in chiral recognition and enantioselective catalysis. Porphyrins possess a number of structural features that make them attractive for the stereocontrol of chiral recognition and metal-catalyzed asymmetric reactions. This article is a brief account of our studies on chiral recognition and enantioselective catalysis by optically active metalloporphyrins. Some of...

Journal: :Dalton transactions 2012
Byungman Kang Ryan K Totten Mitchell H Weston Joseph T Hupp SonBinh T Nguyen

Covalently linked cyclic metalloporphyrin dimers and tetramers have been demonstrated to be good shape-selective hosts for fullerene guests. The fullerene affinities of these hosts can readily be tuned by modulating the covalent linkage and the metal ions in the porphyrin subunits. A rigid Zn(porphyrin) dimer with conjugated bis(alkynyl) linkers exhibits a high selectivity towards C(70) over C(...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Kushal Sengupta Sudipta Chatterjee Subhra Samanta Abhishek Dey

Heme/porphyrin-based electrocatalysts (both synthetic and natural) have been known to catalyze electrochemical O2, H(+), and CO2 reduction for more than five decades. So far, no direct spectroscopic investigations of intermediates formed on the electrodes during these processes have been reported; and this has limited detailed understanding of the mechanism of these catalysts, which is key to t...

Journal: :The Biochemical journal 1963
O T JONES

A monoester of magnesium protoporphyrin has been isolated by Granick (1961) from a chlorophyll-less mutant of Chlorella and from etiolated barley leaves treated with 8-aminolaevulic acid and aaoc-bipyridyl. It was considered likely that this material was a methyl ester that Granick then proposed as an intermediate in the biosynthesis of chlorophyll. The extraction from Rhodop8eudomona spheroide...

Journal: :The Biochemical journal 1967
M Z Atassi

1. The preparation and characterization of manganese, iron, cobalt, nickel, copper and zinc metalloporphyrins is described. Ferrihaem was also esterified with pyrid-4-ylpropanol and the derivative characterized as the diester. 2. Complexes of these various porphyrins, as well as protoporphyrin IX, with apomyoglobin were formed and the resulting artificial myoglobins characterized. 3. Very littl...

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