Peroxidase-like catalytic activities of ionic metalloporphyrins supported on functionalised polystyrene surface

Metalloderivatives of anionic tetrasulphonated tetraphenylporphyrin (MTPPS, M = Mn(III), Fe(III) and Co(III)) were synthesized and immobilized on cationically functionalised divinylbenzene(DVB)-crosslinked polystyrene(PS). These supported catalysts (PS-MTPPS) were found to exhibit peroxidase-like activity. The co-oxidation of 4-aminoantipyrine and phenol by H₂O₂ was attempted with these catalysts to mimic this enzyme function. The catalytic efficiency of all these immobilized MTPPS was found to be superior to the corresponding unsupported MTPPS in solution. The effect of the central metal ion of the porphyrin, pH of the reaction medium and also the temperature effect are investigated. The ideal pH was seen to be in the 8.0–8.5 range, with maximum effect at 8.2. The efficiency order for the various PS-MTPPS was seen to be Co>Mn>Fe, with CoTPPS showing efficiency comparable to that of horseradish peroxidase. The catalytic efficiency was found to be increasing with temperature for all the catalysts. The re-usability of these PS-MTPPS systems for peroxidase-like activity was also studied and it was found that they exhibited a very high degree of recyclability without much poisoning.     

位阻型金属卟啉的合成及其催化烷烃基化的反应

本文用平衡法制备了中位-四(3,5-二叔丁基-4-甲氧基等基)卟啉(T~D~T~B~M~OPP), 并制备了该卟啉的铁、锰、钴、锌、铜、镍的金属配合物。经红外光谱、电子光谱、核磁共振谱, 元素分析等确认了这些均未见报道的金属卟啉。考察了在温和条件下, 以T~D~T~B~M~O PP Fe^III C和T~D~T~B~M~O PP Mn^III Cl为了催化剂, PhIo为氧化剂, 在CH~2Cl~2中氧化n-C~6H~1~4的反应, 并将结果与别的催化剂进行了比较。     

金属卟啉催化环己烷羟基化反应中环己酮的形成机理研究

单金属卟啉和双金属卟啉催化下PhIO常温氧化环己烷的羟基化反应中金属卟啉结构和反应溶剂、反应温度、反应时间等环境因素对产物酮含量及酮形成反应动力学的影响进行了系统研究, 并与金属卟啉催化下PhIO氧化环己醇的反应进行了对比, 提出了金属卟啉催化下环己烷羟基化反应中产物酮的形成机理。     

金属卟啉催化环己烷羟基化反应中环己酮的形成机理研究

单金属卟啉和双金属卟啉催化下PhIO常温氧化环己烷的羟基化反应中金属卟啉结构和反应溶剂、反应温度、反应时间等环境因素对产物酮含量及酮形成反应动力学的影响进行了系统研究, 并与金属卟啉催化下PhIO氧化环己醇的反应进行了对比, 提出了金属卟啉催化下环己烷羟基化反应中产物酮的形成机理。     

Synchronously synthesizing and immobilizing porphyrins on crosslinked polystyrene microspheres and preliminary study on catalytic activity of supported metalloporphyrins

A novel method for immobilizing porphyrins as well as metalloporphyrins (MPs) on polymeric supports was found, and it is the way to synchronously synthesize and immobilize porphyrins on polymeric microspheres. By using 4‐hydroxybenzaldehyde (HBA)‐bound crosslinked polystyrene (CPS) microspheres, pyrrole, and benzaldehyde in a solution as co‐reactants and through the Adler's reaction between solid–liquid phases, it was successfully realized to simultaneously synthesize and immobilize phenyl porphyrin (PP) on CPS microspheres, resulting in PP‐supported microspheres PP–CPS. With the same method, substituted PPs, 4‐chlorophenyl porphyrin (CPP) and 4‐nitrophenyl porphyrin (NPP), were also successfully immobilized on CPS microspheres by using substituted benzaldehydes, 4‐chlorobenzaldehyde and 4‐nitrobenzaldehyde, as one reactant in the solution, respectively, and other two porphyrin‐supported microspheres, CPP–CPS and NPP–CPS, were obtained. The effects of various factors on the process of synchronously synthesizing and immobilizing porphyrins on CPS microspheres were mainly studied. Further, the coordination reaction of cobalt salt with PP–CPS as well as CPP–CPS and NPP–CPS was conducted, forming three solid catalysts, CoPP–CPS, CoCPP–CPS, and CoNPP–CPS. The catalytic properties of these catalysts in the catalytic oxidation of ethylbenzene to acetophenone by dioxygen were preliminarily examined. The experimental results indicate that the Adler's reaction between solid–liquid phases, namely the reaction between HBA‐bound CPS microspheres and pyrrole as well as free benzaldehyde or analogs in the solution can favorably be carried out. For this process, the fitting protonic acid catalyst is p‐nitrobenzoic acid and appropriate solvent is dimethyl sulfoxide (DMSO). By comparison, the process of preparing CPP–CPS microspheres is easier to be carried out. The obtained three solid catalysts can effectively catalyze the oxidation of ethylbenzene to acetophenone by dioxygen. In comparison, the catalytic activity of CoNPP–CPS is the highest. Copyright © 2009 John Wiley & Sons, Ltd.     

疏水性金属卟啉的合成及催化性能研究

本文合成了一类带疏水性长链的对称卟啉及其金属配合物, 研究了该类金属卟啉在CH2Cl2/H2O两相体系中催化苯乙烯的环氧化反应性能。通过以上研究, 发现催化反应体系中水相PH值对烯烃环氧化反应有很大影响; 改变金属卟啉的疏水性对催化反应影响不大; 具不同中心金属离子的金属卟啉有不同的催化活性, 催化活性顺序为:Mn>Co>Ni>Cu。     

Synthesis and characterization of Pd catalysts supported on carbon microspheres for formic acid oxidation

A facile preparation of Pd catalyst using carbon microspheres as support was introduced in this paper. The carbon microspheres were prepared with a simple method from dextrose via hydrothermal process and used as catalysts support for formic acid electrooxidation. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses revealed that the as-prepared face-centered cubic crystal Pd nanoparticles were well-dispersed on the surface of the carbon microspheres, and the mean diameter of the nanoparticles was 8.8 nm. The effect of the support on the catalyst performance for formic acid electrooxidation was studied. The as-prepared catalyst showed the enhanced electrochemical surface active area and the higher electrocatalytic activity towards formic acid oxidation compared with Pd/CNTs and Pd/XC-72 catalysts prepared at room temperature. Electrochemical analysis suggested that the carbon microspheres might be good candidates to be used as the supports of catalyst for formic acid electrochemical oxidation.     

长链烷氧取代金属卟啉的合成及催化性能研究

本文报道了一类长链烷氧取代金属卟啉化合物3的合成.研究了由化合物3与表面活性剂:十二烷基三甲基溴化铵所形成的混合胶束体系作为仿细胞色素P-450加氧酶模拟物对苯乙烯环氧化的催化活性.结果表明:在胶束体系中长链烷氧取代金属卟啉的催化效率优于对称四甲苯基金属卟啉,由此证实:混合胶束中,疏水内核提供的模拟酶的疏水微环境,在苯乙烯环氧化反应中起着重要作用.     

Synthesis, characterization, and catalytic activity of phosphomolybdic acid supported on hydrous zirconia

A series of ecofriendly solid acid catalyst was synthesized by phosphomolybdic acid impregnated on hydrous zirconia (ZPMA) by an incipient wetness impregnation technique. The support and the resulting catalysts were characterized by X-ray diffraction, FTIR, EPMA, BET surface area, acid sites, etc. These studies indicate that the phosphomolybdic acid keeps its Keggin-type structure unaltered up to 500 degrees C. Catalytic activities of the material were evaluated for the esterification of acetic acid reaction. The 12 wt% of phosphomolybdic acid supported on hydrous zirconia shows highest surface area, acid sites and gives about 86% conversion with 100% selectivity of n-butyl acetate.     

Nonswellable and swellable ethylene glycol dimethacrylate-acrylic acid copolymer microspheres

In this study, nonswellable and swellable poly(ethylene glycol dimethacrylate/acrylic acid) copolymer microspheres, in the size range of 50–150 μm, were produced by conventional and modified suspension copolymerizations of the respective monomers, i.e., ethyleneglycol dimethacrylate (EGDMA) and acrylic acid (AA) in aqueous media. Poly(vinyl alcohol) and benzoyl peroxide were used as the stabilizer and the initiator. The diluent, i.e., toluene was included in the polymerization recipe of the modified suspension polymerization. The microspheres were characterized by optical microscopy, FTIR, and FTIR-DRS, and potentiometric titrations. Highly crosslinked, transparent, and nonswellable poly(EGDMA/AA) microspheres were obtained with the conventional suspension polymerization procedure. The modified suspension polymerization provided swellable, opaque, and crosslinked copolymer microspheres. Acrylic acid incorporation into the copolymeric microspheres were significantly higher in the modified procedure, relative to the conventional procedure. © 1996 John Wiley & Sons, Inc.     

Styrene-hydroxyethyl methacrylate copolymer-supported porphyrinatomanganese(III) complexes: synthesis and catalytic cyclohexane hydroxylation with molecular oxygen

Two new styrene-hydroxyethyl methacrylate copolymers containing immobilized porphyrinatomanganese(III) were prepared and characterized as microspheres by SEM, UV–Vis, FT-IR, and TG-DTG. Their catalytic activities have been investigated for the hydroxylation of cyclohexane in the presence of molecular oxygen under mild conditions. The copolymer microspheres proved to be more efficient catalysts than the corresponding non-supported porphyrinatomanganese(III) complex. The alkylated polymer microspheres with porphyrinatomanganese(III) had the highest catalytic activity, which may be attributable to the hydrophobic microenvironment around the porphyrinatomanganese(III) centers, resulting from the alkyl groups.     

金属卟啉催化条件下有机化合物与二氧化碳的电羧化反应Ⅰ. 金属卟啉对苄基氯电羧化催化活性的研究

本文研究了系列金属卟啉对苯基氯(phCH~2Cl)和CO~2电羧化反应的催化活性.用熔点,MS,IR,UV鉴别产物为苯乙酸卟脂,利用高效液相色谱(HPLC)定量分析了羧化产物,选出最佳电羧化电解电位为-1.6v(相对于饱和甘汞电极,vs.SCE,下同). 并对催化活性较高的钴卟啉系列配合物进行了深入研究. 探讨了金属卟啉具有催化活性的原因,认为能形成M(Ⅰ)中间体的金属卟啉配合物.具有较高的催化活性.     

铁卟啉化合物的合成及其催化环己烷羟基化反应的研究

合成了15种卟啉环上具有不同取代基和纵轴上具有不同配位基的TRPPFe^ⅢCl和TPPFe^ⅢX, 从反应速率、反应产率和产物选择性等方面考察了卟啉环上取代基R和纵轴配位基X对这些铁卟啉在温和条件下催化环己烷羟基化反应催化性能的影响,还研究了反应溶剂、反应温度以及有机碱等环境因素对铁卟啉催化性能的影响,获得了一些新的结果和规律。     

Cu-incorporated mesoporous materials: Synthesis, characterization and catalytic activity in phenol hydroxylation

A series of novel Cu-incorporated mesoporous materials (CMMs) with molar ratios of Cu/Si ranging from 1/200 to 1/20 were synthesized by sol–gel method using glutaric acid as template. The materials were characterized by powder X-ray diffraction (XRD), N₂ adsorption, diffuse reflectance UV–vis spectroscopy and transmission electron microscopy (TEM). The results indicate that the CMMs have a three-dimensional (3D) worm-like mesoporous structure with a surface area between 600 and 800 m² g⁻¹ and the copper ions are incorporated into the matrix with octahedral environment. The catalytic activity of these CMMs in the phenol hydroxylation using H₂O₂ as oxidant is comparable to that of TS-1. Effects of Cu/Si molar ratio in the catalyst and the influence of various reaction parameters on the catalytic activity were investigated in detail and the optimized reaction condition was acquired.     

Preparation of heterogeneous cationic metalloporphyrin/heteropolyanion composite catalysts and their high catalytic activity in hydroxylation of cyclohexane with molecular oxygen

A new route to improve the metalloporphyrin catalysts is developed, and it is to constitute heterogeneous composite catalysts with immobilized cationic metalloporphyrins and heteropolyanions. By using the method of synchronously synthesizing and immobilizing porphyrins on cross-linked polystyrene microspheres (CPS microspheres), the immobilized porphyrin TAPP-CPS microspheres, on which ternary amine (TA) group-containing phenyl porphyrin (PP) was immobilized, were first prepared, and then the immobilized cationic porphyrin TMPP-CPS microspheres, in whose structure trimethylammoniophenyl porphyrin (TMPP) was contained, were obtained via quaternization reaction. Finally, three immobilized metalloporphyrins, CoTMPP-CPS (shorten as CoP-CPS), MnTMPP-CPS (MnP-CPS) and FeTMPP-CPS (FeP-CPS), were gained through coordination reactions. These immobilized metalloporphyrins were composited with heteropolyanions by right of the mutual electrostatic interaction with phosphotungstic (PW) acid and phosphomolybdic (PMo) acid as reagents, respectively, resulting in several heterogeneous metalloporphyrin/heteropolyanion composite catalysts such as CoPPW-CPS, CoPPMo-CPS and MnPPW-CPS. The composite catalysts were used in the catalytic hydroxylation reaction of cyclohexane with molecular oxygen as oxidant, and their catalytic performances were investigated. The experimental results show that the heterogeneous composite catalysts have extraordinarily high catalytic activity in the hydroxylation reaction of cyclohexane by molecular oxygen, and the cyclohexanol yield in 8 h can get up to 45.5 %. More importantly, the catalytic activity of the heterogeneous composite catalysts is obviously higher than that of the immobilized cationic metalloporphyrins, and the enhanced catalytic activity is originated from a protection of heteropolyanions against the deactivation of metalloporphyrins.     

Cu/SBA-1的合成及其对苯羟化反应的催化性能

以正硅酸乙酯(TEOS)为硅源,十六烷基三乙基溴化铵(CTEABr)为模板剂,在强酸性条件下采用溶胶-凝胶法合成了Cu掺杂SBA-1分子筛.用XRD、SEM、N2吸附/脱附、红外光谱对所制备的样品进行表征.XRD测定结果显示所合成的Cu/SBA-1具有明显的立方介孔结构,Cu/SBA-1比表面积达931 m2·g-1,...     

Catalytic hydrotreatment of humins into cyclic hydrocarbons over solid acid supported metal catalysts in cyclohexane

Humins are common undesirable sideproducts during many acid-catalyzed reactions in renewable biomass platform conversion. However, few studies have been reported to the efficient utilization of humins.For the first time, the selective catalytic conversion of biomass-derived humins into cyclic hydrocarbons with high conversion rate and selectivity is presented using a home-made Ru/W-P-Si-O bifunctional catalyst. The multistage polymerization structure of humins was studied through controlled experiments.Results show that the CAC bond network can be efficiently depolymerized at a mild reaction temperature of 340–380 °C, catalyzed by the cooperative catalysis of nano-Ru particles and porous strong Lewis solid acid. Particularly, 95.4% conversion of humins was achieved under the optimal condition with up to 88.3%yield of cyclic hydrocarbons. The detailed composition after liquefaction was also analyzed. This study paves the way for the efficient production of cyclic and aromatic hydrocarbons from furan-derived humin polymer through Lewis acid-catalyzed Diels–Alder reactions between furan rings.     

Synthesis, characterization, and catalytic performance of copper-containing SBA-15 in the phenol hydroxylation

A series of copper-containing SBA-15 samples were successfully synthesized via evaporation-induced self-assembly route. The resulting materials were characterized by X-ray diffraction (XRD), (29)Si MAS NMR spectroscopy, transmission electron microscopy (TEM), N(2) sorption, inductively coupling plasma-atomic emission spectrometer (ICP-AES), thermogravimetry, and differential thermal analysis (TG-DTA), Fourier-transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectra (UV-vis) and X-ray photoelectron spectroscopy (XPS). The results indicated that: (1) all the samples exhibited typical hexagonal arrangement of mesoporous structure; (2) copper ions could be incorporated into the framework of SBA-15; (3) the addition of urea in the hydrothermal stage efficiently reduced the leaching of copper and improved the thermal stability of the mesoporous materials. Catalytic performances of the obtained materials were evaluated in the hydroxylation of phenol with H(2)O(2). The catalytic tests showed that the synthesized materials exhibited high activity for this reaction and copper ions in the framework were more active than copper species in the extra-framework position. The nitric acid treatment on the samples removed the bulk CuO species, which resulted in a dramatic increase in the catalytic activity.     

Synthesis and catalytic properties of manganese complexes of substituted tetraphenylporphyrins in the stereoselective hydroxylation of cholesterol

Manganese(III) complexes of 5-(p-aminophenyl)-10,15,20-triphenylporphyrin, 2-(2-carboxyvinyl)-5, 10,15,20-tetraphenylporphyrin, and their derivatives containing electron-donor and electron-acceptor substituents have been synthesized. Manganese(III) porphyrinates (PMn) are catalytically active in the stereoselective hydroxylation of cholesterol to form 3,5-cholestanediol. The influence of substitutents in the porphyrin ring on the ability of PMn to associate in solution, the hydroxylation rate constants, and the turnover number of the catalyst are discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1656–1660, September, 1994.The present work was financially supported by the Russian Foundation for Basic Research (Projects No. 94-03-08070 and 93-03-18307).     

Preparation of styrene/methacrylic acid copolymer microspheres and their composites with metal particles

 Poly(styrene-co-methacrylic acid) [P(St-co-MAA)] microspheres were prepared by emulsifier-free emulsion copolymerization of St with MAA. Fourier transform IR spectroscopy and elemental analysis were used to study the change in the content of MAA in the microspheres. The results of X-ray photoelectron spectroscopy measurements indicated the presence of carboxylic functionality on the surface of the microspheres. The P(St-co-MAA) metal composite particles were prepared by chemical metal deposition. Transmission electron microscopy observation and X-ray diffraction measurement were used to study the distribution and structure of the metal particles deposited. Received: 15 September 1999 Accepted: 24 December 1999