First insight into catalytic activity of anionic iron porphyrins immobilized on exfoliated layered double hydroxides

Nakagaki, Shirley; Halma, Matilte; Bail, Alesandro; Arízaga, Gregório Guadalupe Carbajal; Wypych, Fernando

doi:10.1016/j.jcis.2004.08.098

Cited by 83 publications

(52 citation statements)

References 33 publications

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“…[1][2][3][4] This class of compounds is used in solution or following immobilization in organic amorphous polymers and crystalline inorganic materials such as silica, [5][6][7] zeolites, 8,9 clay from the smectite group (montmorillonite) 10,11 and others. [12][13][14][15][16] The use of metalloporphyrins substituted with electron-withdrawing groups (the so-called second generation porphyrins 17 ) and their immobilization, has resulted in efficient and selective catalysts for oxidation reactions, since the support can impose shape selectivity and promote a special environment, favoring the approach of the substrate to the active catalytic specie. [5][6][7]12,13,18 In addition, the immobilization may prevent molecular aggregation or bimolecular self-destruction reactions, which can lead to deactivation of catalytically active metalloporphyrin species.…”

Section: Introductionmentioning

confidence: 99%

Catalytic activity in oxidation reactions of anionic iron(III) porphyrins immobilized on raw and grafted chrysotile

Nakagaki¹,

Castro²,

Machado³

et al. 2006

J. Braz. Chem. Soc.

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Crisotila natural e quimicamente modificada foi usada como matrizes para imobilização de ferroporfirinas de segunda geração. As atividades catalíticas dos sólidos obtidos foram avaliadas em reações de oxidação de cicloexano, usando iodosilbenzeno como oxidante. Os resultados de catálise foram analisados e comparados aos obtidos pela imobilização das mesmas ferroporfirinas em sílica funcionalizada com 3-APTS, derivadas do tratamento ácido da crisotila. Os resultados preliminares mostraram que os catalisadores são eficientes e seletivos para a obtenção de álcool.Natural and grafted chrysotile were used as matrices for the immobilization of second generation iron porphyrins. The catalysts obtained were evaluated in the oxidation reaction of cyclohexane, using iodosylbenzene as oxidant agent. The catalyst activity for different conditions was compared with results for the same porphyrins immobilized with 3-APTS grafted disordered silica, obtained from acid-leached chrysotile. Preliminary results have shown that high activity can be obtained with short reaction times, and that the reaction is specific for alcohol.

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Section: Introductionmentioning

confidence: 99%

Catalytic activity in oxidation reactions of anionic iron(III) porphyrins immobilized on raw and grafted chrysotile

Nakagaki¹,

Castro²,

Machado³

et al. 2006

J. Braz. Chem. Soc.

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“…23,40 Shortly, 10 mL of formamide and 25 mg of solid LDHM were mixed in an Erlenmeyer flask, and the mixture was stirred in an ultrasound bath for 2 h. An almost translucent milky suspension emerged, which suggested the formation of macroporous LDH by exfoliation (solid LDHME). The solid anionic FeP (3.8 × 10 −6 mol) was added to the suspension, and the mixture was kept under magnetic stirring for 24 h. A reddish brown solid (FeP-LDHME) arose.…”

Section: Methodsmentioning

confidence: 99%

“…8,15,18 To minimize such problems, researchers have turned to the synthesis of new robust and resistant porphyrin structures 10,22 as well as to immobilization of these catalysts in different inorganic supports. [22][23][24][25][26][27][28][29][30][31][32][33] Catalyst immobilization can facilitate catalyst recovery from the reaction medium, to enable their reuse and recycling. 17,[33][34][35][36][37][38][39] This is particularly attractive from an economical and environmental viewpoint.…”

Section: Introductionmentioning

confidence: 99%

“…In this context, layered double hydroxides (LDHs) have emerged as interesting supports to immobilize a variety of MPs. 18,23,[40][41][42][43][44] LDHs are synthetic layered compounds that contain divalent and trivalent metal cations [M(II) and M(III)] in a structure derived from the mineral brucite. In LDHs, M(III) metal ions replace part of the M(II) metals in the brucitelike structure, to give excess positive charge in the layers, counterbalanced by intercalating hydrated anions.…”

Section: Introductionmentioning

confidence: 99%

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Anionic Iron(III) Porphyrin Immobilized on/into Exfoliated Macroporous Layered Double Hydroxides as Catalyst for Oxidation Reactions

Nakagaki¹,

Castro²,

Ucoski³

et al. 2014

Journal of the Brazilian Chemical Society

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A oxidação de substratos orgânicos é uma importante classe de reações explorada visando a produção de insumos industriais tais como epóxidos, álcoois e cetonas. As metaloporfirinas são compostos com reconhecida atividade catalítica que mimetizam processos de oxidação que ocorrem em seres vivos. A sua imobilização em diferentes sólidos robustos e inertes permite a recuperação e reuso do catalisador em processos catalíticos heterogêneos. Hidróxidos duplos lamelares (LDHs) são materiais inorgânicos constituídos de hidróxidos de metais di e trivalentes, resultando em lamelas bidimensionais carregadas positivamente. Neste trabalho reportamos a preparação de catalisadores baseados na imobilização de ferroporfirina (FeP) em LDH macroporoso (LDHM) obtido pelo método de co-precipitação usando poliestireno como template, reconstrução de óxidos e esfoliação (LDHME). A imobilização da FeP no LDH intercalado com ânions nitrato obtido pelo método de co-precipitação também é reportada. Os sólidos obtidos foram caracterizados e investigados como catalisadores na oxidação do cicloocteno e cicloexano.The oxidation of organic substrates via catalytic routes is an important class of reactions to produce industrial input materials such as epoxides, alcohols, and ketones. Metalloporphyrins display recognized catalytic activity that mimics oxidation processes in living organisms. Their immobilization in different inert supports allows their recovery and reuse in heterogeneous catalytic processes. Layered double hydroxides (LDHs) are inorganic materials consisting of di-and trivalent metal hydroxides that afford bidimensional positively charged layers. This work reports on the preparation of the solid based on macroporous LDHs (LDHMs) by the co-precipitation method, which involved the use of polystyrene as template, oxides reconstruction, and exfoliation, to furnish LDHME. We also describe the immobilization of an iron(III) porphyrin (FeP) in LDHME and in LDH intercalated with nitrate anions, obtained by the co-precipitation method. Application of the immobilized catalysts in (Z)-cyclooctene and cyclohexane oxidation will help to assess their catalytic activity. Keywords: porphyrin, macroporous LDH, oxidation, biomimetic reaction, heterogeneous catalysis IntroductionThe family of enzymes collectively known as cytochrome P450 monooxygenases bear a heme prosthetic group and participate in different catalytic processes, mainly oxidative metabolism of endogenous/exogenous products in mammals. [1][2][3][4][5] Over the last years, researchers have made great efforts to develop routes that can generate robust synthetic metalloporphyrins (MPs), 6-10 aiming to mimic biological enzymes such as cytochrome P450 (biomimetic approach). Indeed, MPs can efficiently and selectively catalyze hydrocarbon oxidation.11 Some of these MPs are based on the structure of meso-tetraphenylporphyrin [H 2 (TPP)].The high efficiency and selectivity of MPs have motivated the proposition of technological catalytic systems based on this versatile family of oxidation ca...

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“…More recently, porous metalloporphyrin networks have proven to be potentially applicable as efficient heterogeneous catalysts 5 after immobilization in organic amorphous polymers, amorphous inorganic matrices, or crystalline inorganic materials such as silica, 6,7 zeolites, 8,9 clay from the smectite group (montmorillonite), [10][11][12] layered double hydroxides, 13,14 tubular and fibrous matrices, 15 silica matrix obtained by the sol-gel process, among others. [16][17][18][19][20][21][22][23] This versatile class of molecules is efficient and selective for the heterogeneous catalytic hydroxylation and epoxidation of a wide variety of organic substrates.…”

Section: Introductionmentioning

confidence: 99%

Preparation of catalysts based on iron(III) porphyrins heterogenized on silica obtained by the Sol-Gel process for hydroxylation and epoxidation reactions

Castro¹,

Halma²,

Machado³

et al. 2010

J. Braz. Chem. Soc.

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Catalisadores sólidos foram preparados pela interação de ferroporfirinas com sílica obtida pelo processo sol-gel. A presença da ferroporfirina na matriz de sílica e a morfologia das partículas obtidas foram estudadas por espectroscopia eletrônica na região do ultravioleta e visível, difratometria de raios X de pó, espectroscopia vibracional na região do infravermelho, microscopia eletrônica de transmissão, ressonância paramagnética eletrônica e análises termogravimétricas. A atividade catalítica dos sólidos obtidos foi investigada frente a oxidação dos substratos (Z)-cicloocteno, cicloexeno e cicloexano por iodosilbenzeno em meio de diclorometano e acetonitrila. Os resultados catalíticos obtidos foram comparáveis àqueles observados quando as ferroporfirinas em solução (catálise homogênea) foram utilizadas.Solid catalysts have been prepared by chemical interaction of iron(III) porphyrins with the surface of the pores of a silica matrix obtained by the sol-gel method. The presence of the complexes in the silica matrix and the morphology of the obtained particles were studied by UV-Vis spectroscopy, powder X-ray diffractometry, infrared spectroscopy, transmission electron microscopy, electron paramagnetic resonance and thermogravimetric analysis. The catalytic activity of the immobilized iron(III) porphyrins in the oxidation of (Z)-cyclooctene, cyclohexene and cyclohexane was evaluated in dichloromethane/acetonitrile 1:1 solvent mixture (v/v) using iodosylbenzene as oxidant. Results were compared with those achieved with the homogeneous counterparts.

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First insight into catalytic activity of anionic iron porphyrins immobilized on exfoliated layered double hydroxides

Cited by 83 publications

References 33 publications

Catalytic activity in oxidation reactions of anionic iron(III) porphyrins immobilized on raw and grafted chrysotile

Catalytic activity in oxidation reactions of anionic iron(III) porphyrins immobilized on raw and grafted chrysotile

Anionic Iron(III) Porphyrin Immobilized on/into Exfoliated Macroporous Layered Double Hydroxides as Catalyst for Oxidation Reactions

Preparation of catalysts based on iron(III) porphyrins heterogenized on silica obtained by the Sol-Gel process for hydroxylation and epoxidation reactions

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