Reversible adsorption of oxygen on silica gel modified by imidazole-attached iron tetraphenylporphyrin

Leal, O.; Anderson, David L.; Bowman, Robert G.; Basolo, Fred; Burwell, Robert L.

doi:10.1021/ja00851a017

Cited by 140 publications

(43 citation statements)

References 4 publications

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“…17 Chloropropyl silica (CPS) was prepared by refluxing a suspension of silica gel in a solution of 3-chloropropyltrimethoxysilane in toluene according to the method described by Leal et al 18 The solid obtained were dried under vacuum at 100 °C for 8 h. From corresponding elemental analysis the amount of immobilization were estimated: SiN + = 5.3 × 10 -4 mol of propyltrimethylammonium/g; SiN + (IPG) = 2.3 ×10 -4 mol of imidazole/g; CPS = 1.1 × 10 -3 mol of chloropropyl/g.…”

Section: Solid Supportsmentioning

confidence: 99%

Modified silicas covalently bounded to 5,10,15,20-tetrakis(2-hydroxy-5-nitrophenyl)porphyrinato iron(III): synthesis, spectroscopic and EPR characterization. Catalytic studies

Elisa

Vinhado

Serra

et al. 2008

J. Braz. Chem. Soc.

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Neste trabalho estudamos a epoxidação do cicloocteno com PhIO utilizando uma nova porfirina 5,10,15,20-tetraquis(2-hidroxi-5-nitrofenil) In this work we have studied cyclooctene epoxidation with PhIO, using a new iron porphyrin, 5,10,15,20-tetrakis(2-hydroxy-5-nitrophenyl)porphyrinato iron(III), supported on silica matrices via eletrostatic interaction and / or covalent bonds as catalyst. These catalysts were obtained and immobilized on the solid supports propyltrimethylammonium silica (SiN species in all of the three obtained catalysts. In the case of (Z)-cyclooctene epoxidation by PhIO the yields observed for cis-epoxycyclooctane were satisfactory for the reactions catalyzed by the three materials (ranging from 68% to 85%). Such results indicate that immobilization of metalloporphyrins onto solid supports via groups localized on the ortho positions of their mesophenyl rings can lead to efficient catalysts for epoxidation reactions. The catalyst 1-CPS is less active than 1-SiN and 1-SiN(IPG), this argues in favour of the immobilization of this metalloporphyrin onto solids via electrostatic interactions, which is easier to achieve and results in more active oxidation catalysts. Interestingly, the activity of the supported catalysts remained the same even after three successive recyclings; therefore, they are stable under the oxidizing conditions.

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Section: Solid Supportsmentioning

confidence: 99%

Modified silicas covalently bounded to 5,10,15,20-tetrakis(2-hydroxy-5-nitrophenyl)porphyrinato iron(III): synthesis, spectroscopic and EPR characterization. Catalytic studies

Elisa

Vinhado

Serra

et al. 2008

J. Braz. Chem. Soc.

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“…The imidazolylpropyt gel was prepared as previously described [9]. Five grams of silica gel material (SILASORB, SILIKASPHER or MCM -41) were dried at 160~ and refluxed 3 h in xylene with 1 g of imidazole and 1.5 g of 3 -chloropropyltriethoxysilane.…”

Section: Introductionmentioning

confidence: 99%

Sorption of cobalt on modified silica gel materials

Rajec

Hanzel²

2003

Czech J Phys

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R. HANZELALLDECO, SK-919 31 Jaslovsk( Bohunice Silica gel materials were chemically modified with imidazole. The degree of functionalisation of the covalently attached molecule was calculated from C, H, N analysis and ranged between 0.270 and 0.552 mmol/g, depending on the reflux time and silica gel matrix used. Experimental sorption capacity for cobalt ranged from 0.038 to 0.228 mmol/g.Synthesised hexagonal mesoporous silica matrix MCM -41 with uniform pore diameter < 400 nm was used too. Change of pore diameters of silica gel support to larger pores has a positive influence on access of cobalt ion to sorption centres and increases sorption capacity of sorbents.The sorption of cobalt under various conditions (pH, contact time of phases) with constant liquid-solid ratio (V/m = 50 mL/g) was studied. The distribution coefficients ranged between 200 and 50 000 mL/g according to the silica gel matrix used. The influence of presence of other heavy or toxic metals and the influence of sodium and potassium on sorption of Co (II) from aqueous solutions was investigated. Influence of different metals on cobalt sorption decreases in the order Hg > Cu > Cd > Zn, Fe > Mn > A1, Cr.

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“…Complexes immobilized by an impregnation procedure on an inert matrix surface have been used to prepare chemically modified electrodes viewing numerous electrocatalytic reactions [5][6][7][8][9][10][11][12] . Another procedure has been to immobilize the phthalocyanine or porphyrine complexes by a chemical bonding of the central metal atoms to basic groups grafted on solid surfaces [13][14][15][16][17][18][19][20][21] .…”

Section: Introductionmentioning

confidence: 99%

Cobalt(II) phthalocyanine bonded to 3-n-propylimidazole immobilized on silica gel surface: preparation and electrochemical properties

Fujiwara¹,

Gushikem²

1999

J. Braz. Chem. Soc.

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A ftalocianina de cobalto(II) imobilizada sobre a sílica gel (área superficial SBET = 500 m 2 g -1 ) modificada com 3-n-propilimidazol, foi incorporada a um eletrodo de pasta de carbono e mostrou-se eficiente na eletrocatálise da oxidação do ácido oxálico. As interações intermoleculares do complexo, as quais podem normalmente interferir no processo redox, praticamente não foram observadas no presente caso, devido a baixa densidade média do complexo na superfície do material sintetizado δ = 4,7 x 10

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Reversible adsorption of oxygen on silica gel modified by imidazole-attached iron tetraphenylporphyrin

Cited by 140 publications

References 4 publications

Modified silicas covalently bounded to 5,10,15,20-tetrakis(2-hydroxy-5-nitrophenyl)porphyrinato iron(III): synthesis, spectroscopic and EPR characterization. Catalytic studies

Modified silicas covalently bounded to 5,10,15,20-tetrakis(2-hydroxy-5-nitrophenyl)porphyrinato iron(III): synthesis, spectroscopic and EPR characterization. Catalytic studies

Sorption of cobalt on modified silica gel materials

Cobalt(II) phthalocyanine bonded to 3-n-propylimidazole immobilized on silica gel surface: preparation and electrochemical properties

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