Covalent grafting of copper–amino acid complexes onto chloropropylated silica gel—an FT-IR study

Jakab, Noémi; Hernádi, Klára; Kiss, János; Pálinkó, István

doi:10.1016/j.molstruc.2004.10.073

Cited by 7 publications

(5 citation statements)

References 4 publications

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“…31 In the zeolite, however, one of the histidine ligands is replaced by lattice oxygen atoms next to an ion exchange site. In another approach, amino acids were immobilized on a chloropropyl-functionalised silica 33 or polystyrene support. 34 The amino acids were either protected on the N-terminal or on the C-terminal and covalently anchored to the chloropropyl moiety on the surface.…”

Section: Introductionmentioning

confidence: 99%

The characterisation and catalytic properties of biomimetic metal–peptide complexes immobilised on mesoporous silica

Pirngruber

Frunz

Lüchinger

2009

Phys. Chem. Chem. Phys.

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The active core of the enzyme methane mono-oxygenase (MMO) contains an iron (or copper) dimer with histidine and glutamic acid ligands located on a His-x-x-Glu sequence of the peptide chain. We mimicked the active core of MMO by immobilising the His-Gly-Gly-Glu motif on a silica support, using the methods of solid phase peptide synthesis, and by allowing complexes with Cu and Fe cations to self-assemble. The dominating mode of coordination in the complexes was elucidated by a group fitting analysis of the extended X-ray absorption fine structure (EXAFS) spectra. The complexation of the metal cations by the short peptide significantly changed (improved) their catalytic properties in the oxidation of cyclohexane by H(2)O(2) or by 3-chloro-perbenzoic acid.

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Section: Introductionmentioning

confidence: 99%

The characterisation and catalytic properties of biomimetic metal–peptide complexes immobilised on mesoporous silica

Pirngruber

Frunz

Lüchinger

2009

Phys. Chem. Chem. Phys.

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“…Even if the complex itself was a good homogeneous catalyst, recovery might be difficult if it was possible at all. Anchoring the complex by various methods (adsorption-hydrogen bonding [9], ion exchange [8][9][10], covalent grafting [9]) onto rigid supports (montmorillonite [8,9], silica gel [9,11] or zeolite [10]) is a solution to this problem-a solid catalyst is always easier to handle than a homogeneous one. When it was done by the ionexchange method a more durable catalyst was obtained with the advantage of being easily recoverable, however, the SOD activity was worse than that of the support-free complex [8].…”

Section: Introductionmentioning

confidence: 99%

Preparation, Characterization and Catalytic Activities of Immobilized Enzyme Mimics

et al. 2008

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In order to find highly active and selective oxygen-transfer catalysts with appreciable durability, Cu(II)-histidine complexes were covalently grafted onto a chlorinated polystyrene resin as copper-containing enzyme mimics. The Cu(II)-histidine complexes and the mobile polymer were to resemble the active center and the proteomic skeleton of the enzymes, respectively. The resulting heterogenized complexes were expected to be nearly so active and more durable catalysts that are easier to recycle than their homogeneous counterparts. The substances were tested in a superoxide radical anion dismutation reaction. Control for the syntheses was exerted by protecting either the N-terminal or the C-terminal of the covalently grafted L-histidine molecules. During the preparative work generally applied methods of synthetic organic chemistry (alkylation or esterification) were used. Various anchored complexes were prepared and characterized by classical analytical methods, different forms of spectroscopy as well as molecular modeling. The covalently grafted complexes having the protected amino acids as ligands displayed remarkably high activities in the superoxide dismutase (SOD) test reaction.

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“…Our strategy was to self-assemble a complex between iron and amino acids by interaction of Fe cations in solution with immobilized amino acid ligands. 16 Amino acids can be covalently anchored on a support by the formation of very stable amide bonds with surface bound amine groups. Aminefunctionalized materials are prepared by several methods, for example, by grafting the commercially available 3-aminopropyl-trimethoxysilane on silica surfaces or by co-condensation of the same trimethoxysilane with a silica precursor (typically TEOS).…”

Section: Introductionmentioning

confidence: 99%

“…22 Instead of immobilizing amino acids via the formation of amide bonds with amine-functionalized surfaces, as it was done here, covalent immobilization of amino acids can also be achieved on 3-cloropropyl-functionalized surfaces. 16 The single amino acids immobilized in that way were used to complex copper ions and showed some activity in oxidation reactions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Immobilized Complexes of Metals with Amino Acid Ligands − A First Step toward the Development of New Biomimetic Catalysts

2006

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The natural amino acids histidine and glutamic acid were immobilized on the surface of functionalized mesoporous silica supports. Histidine and glutamic acid alone and combinations of both were covalently bound to the amino groups on the surface of the support by the formation of amide bonds. The immobilized amino acids were used as ligands for Fe(II). The obtained biomimetic iron complexes were tested as catalysts for cyclohexane oxidation at mild reaction conditions with hydrogenperoxide as oxidant. This stepwise preparation method allowed the synthesis of materials with varying nature and loading of immobilized amino acids. The observed trends in catalytic activity show that both the type and the surface density of immobilized amino acid have an influence on the catalytic performance during cyclohexane oxidation and also on the structure of the immobilized Fe complex.

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Covalent grafting of copper–amino acid complexes onto chloropropylated silica gel—an FT-IR study

Cited by 7 publications

References 4 publications

The characterisation and catalytic properties of biomimetic metal–peptide complexes immobilised on mesoporous silica

The characterisation and catalytic properties of biomimetic metal–peptide complexes immobilised on mesoporous silica

Preparation, Characterization and Catalytic Activities of Immobilized Enzyme Mimics

Immobilized Complexes of Metals with Amino Acid Ligands − A First Step toward the Development of New Biomimetic Catalysts

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