Analysis of the effects of catalytic bleaching on cotton

Hydrogen peroxide can be catalyzed to bleach cotton fibers at temperatures as low as 30°C by incorporating dinuclear tri-μ-oxo bridged manganese(IV) complex of the ligand 1,4,7-trimethyl-1,4,7-triazacyclononane (MnTACN) as the catalyst in the bleaching solution. The catalytic system was found to be more selective under the conditions applied than the non-catalytic H₂O₂ system, showing better bleaching performance while causing slightly lower decrease in degree of polymerization (DP) of cellulose. In order to gain fundamental knowledge of the bleach effect on cotton fibers and cellulose as its main component, especially after catalytic bleaching, X-ray Photoelectron Spectroscopy (XPS) was used to study surface chemical effects. The Washburn method was applied to investigate wetting properties, and liquid porosity was used to obtain pore volume distribution (PVD) plots. Parallel analyzes performed on model cotton fabric, i.e. “clean” cotton fabric stained with morin - a pigment regularly found in native cotton fiber, helped to differentiate between pigment oxidation and other bleaching effects produced on the (regular) industrially scoured cotton fabric. Bleaching was not limited to the chemical action but also affected cotton fiber capillary parameters most likely due to the removal of non-cellulosic materials as well as chain-shortened cellulose.     

Kinetics and mechanism of 1-phenylethanol oxidation by the system hydrogen peroxide-manganese(IV) binuclear complex-oxalic acid

Hydrogen peroxide was found to oxidize 1-phenylethanol to acetophenone in acetonitrile homogeneous solution efficiently at room temperature in the presence of a dimeric complex of manganese (IV) [LMn(O)₃MnL](PF₆)₂(where L = 1,4,7-trimethyl-1,4,7-triazacyclononane) as the catalyst and oxalic acid as a co-catalyst. The number of catalytic cycles was 15 000 3 h after the onset of the reaction. The dependences of the initial rate of acetophenone accumulation on the initial concentrations of the reagents were studied. Based on an analysis of the kinetic data, we conclude that phenylethanol is oxidized by a manganyl particle containing an Mn = O fragment that interacts competitively with hydrogen peroxide.     

Binuclear copper(II) complexes of xylyl-bridged bis(1,4,7-triazacyclononane) ligands

Copper(II) complexes of three bis(tacn) ligands, [Cu(2)(T(2)-o-X)Cl(4)] (1), [Cu(2)(T(2)-m-X)(H(2)O)(4)](ClO(4))(4).H(2)O.NaClO(4) (2), and [Cu(2)(T(2)-p-X)Cl(4)] (3), were prepared by reacting a Cu(II) salt and L.6HCl (2:1 ratio) in neutral aqueous solution [T(2)-o-X = 1,2-bis(1,4,7-triazacyclonon-1-ylmethyl)benzene; T(2)-m-X = 1,3-bis(1,4,7-triazacyclonon-1-ylmethyl)benzene; T(2)-p-X = 1,4-bis(1,4,7-triazacyclonon-1-ylmethyl)benzene]. Crystals of [Cu(2)(T(2)-m-X)(NPP)(mu-OH)](ClO(4)).H(2)O (4) formed at pH = 7.4 in a solution containing 2 and disodium 4-nitrophenyl phosphate (Na(2)NPP). The binuclear complexes [Cu(2)(T(2)-o-XAc(2))(H(2)O)(2)](ClO(4))(2).4H(2)O (5) and [Cu(2)(T(2)-m-XAc(2))(H(2)O)(2)](ClO(4))(2).4H(2)O (6) were obtained on addition of Cu(ClO(4))(2).6H(2)O to aqueous solutions of the bis(tetradentate) ligands T(2)-o-XAc(2) (1,2-bis((4-(carboxymethyl)-1,4,7-triazacyclonon-1-yl)methyl)benzene and T(2)-m-XAc(2) (1,3-bis((4-(carboxymethyl)-1,4,7-triazacyclonon-1-yl)methyl)benzene), respectively. In the binuclear complex, 3, three N donors from one macrocycle and two chlorides occupy the distorted square pyramidal Cu(II) coordination sphere. The complex features a long Cu...Cu separation (11.81 A) and intermolecular interactions that give rise to weak intermolecular antiferromagnetic coupling between Cu(II) centers. Complex 4 contains binuclear cations with a single hydroxo and p-nitrophenyl phosphate bridging two Cu(II) centers (Cu...Cu = 3.565(2) A). Magnetic susceptibility studies indicated the presence of strong antiferromagnetic interactions between the metal centers (J = -275 cm(-1)). Measurements of the rate of BNPP (bis(p-nitrophenyl) phosphate) hydrolysis by a number of these metal complexes revealed the greatest rate of cleavage for [Cu(2)(T(2)-o-X)(OH(2))(4)](4+) (k = 5 x 10(-6) s(-1) at pH = 7.4 and T = 50 degrees C). Notably, the mononuclear [Cu(Me(3)tacn)(OH(2))(2)](2+) complex induces a much faster rate of cleavage (k = 6 x 10(-5) s(-1) under the same conditions).     

Attachment of Nanoparticles to Pyrolytic Graphite Electrode and Its Application for the Direct Electrochemistry and Electrocatalytic Behavior of Catalase

Abstract

A highly hydrophilic, nontoxic, and conductive effect of colloidal gold nanoparticles (GNP) and multi-walled carbon nanotubes (MWCNT) on pyrolytic graphite electrode has been demonstrated. The direct electron transfer of catalase (CAT) was achieved based on the immobilization of MWCNT/CAT-GNP on a pyrolytic graphite electrode by a Nafion film. The immobilized catalase displayed a pair of well-defined and nearly reversible redox peaks in 0.1 M phosphate buffer solution (PBS) (pH 6.98). The dependence of E°′on solution pH indicated that the direct electron transfer reaction of catalase was a single-electron-transfer coupled with single-proton-transfer reaction process. The immobilized catalase maintained its biological activity, showing a surface controlled electrode process with an apparent heterogeneous electron transfer rate constant (k _s) of 1.387±0.1 s^?1 and charge-transfer coefficient (α) of 0.49, and displayed electrocatalytic activity in the electrocatalytic reduction of hydrogen peroxide. Therefore, the resulting modified electrode can be used as a biosensor for detecting hydrogen peroxide.     

Carvone epoxidation by system “hydrogen peroxide-[Mn2L2O3][PF6]2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane)-carboxylic acid”: a combinatorial approach to the process optimization?

Summary Epoxidation of natural terpene (+)-carvone by the system consisting of a catalyst, oxalic acid (co-catalyst) and H₂O₂ (70% aqueous solution; oxidant) was studied and factorial design methods were applied for the optimization of this reaction. A dinuclear manganese(IV) complex [LMn(O)₃MnL](PF₆)₂ (L = 1,4,7-trimethyl-1,4,7-triazacyclononane) was used as a catalyst, and acetonitrile was employed as a solvent. An analysis by methods of the complete 2⁴ factorial design showed that an increase in the catalyst concentration gives a strong positive effect on the carvone conversion and selectivity. Hydrogen peroxide has a smaller positive effect on the conversion, but at high concentration, H₂O₂ leads to some decrease in the selectivity. An increase in the oxalic acid concentration has a beneficial effect on the conversion, but does not affect the selectivity.     

Reactivity of the Coordinated Hydroperoxo Ligand

The reactivity of the hydroperoxo complex [Co(CN)(5)OOH](3)(-) has been studied in aqueous solution. The complex undergoes acid-catalyzed aquation (k = 1.89(5) x 10(-)(2) s(-)(1), pK(a) = 5.21(4), T = 20 degrees C, I = 0.1 M). Assuming an I(d) mechanism, this allows the relative affinity for Co(III) to be deduced as H(2)O(2) < H(2)O < HO(2)(-) and implies H(2)O(2) to be a very weak ligand. At neutral pH the hydroperoxo complex effects efficient oxygen atom transfer to L-methionine to give an intermediate identified as [Co(CN)(5)(L-methionine S-oxide)](2)(-), which then dissociates to [Co(CN)(5)OH(2)](2)(-) and L-methionine S-oxide. The reaction is acid catalyzed and is proposed to take place via nucleophilic attack of sulfur on the proximal oxygen of the hydroperoxo ligand with concerted loss of water. The significance of these results for the interaction of hydrogen peroxide with labile metal ions is discussed.     

Immobilization of the [RuII(edta)NO+] Ion on the surface of functionalized silica gel

The reaction of NO and the immobilized dimer complex (edta)(2)Ru(2)(III(1/2),III(1/2)) on silica gel chemically modified with [3-(2-aminoethyl)aminopropyl]trimethoxysilane (AEATS) produces the corresponding immobilized nitrosyl complex AEATS/Ru(II)NO(+). This compound, a monomer, was obtained by reducing the immobilized ruthenium dimer either electrochemically or with Eu(II) and reacting this species with NO(2)(-) ions. The properties of [Ru(edta)NO](-) in solution and anchored (AEATS/Ru(II)NO(+)) on silica were compared using electrochemical (DPV, CV) and spectroscopic (IR, UV-vis, and ESR) techniques. The results indicate that immobilization does not alter the reactivity of the ruthenium complex and confirm that [Ru(edta)(H(2)O)](2)(-) may be used, either in solution or immobilized, as a catalyst for the conversion of NO(2)(-) to NO(+). Both the anchored nitrosyl complex AEATS/Ru(II)NO(+) and the [Ru(edta)NO](-) species in solution, upon one-electron reduction, liberate NO at comparable rates.     

Evaluation of hexaniobate nanoscrolls as support for immobilization of a copper complex catalyst

In this work, we report the intercalation properties of the hexaniobate nanoscrolls toward insertion of 2-[2-(2-pyridyl)ethylimino-1-ethyl]pyridine-imidazole copper(II), [Cu(apip)imH]2+, a cationic complex able to promote the catalytic oxidation of organic substrates. Hexaniobate was first transformed into its acidic phase, H2K2Nb6O17, and then exfoliated with n-butylamine in water. The copper complex was immobilized into the nanoscrolls obtained by the acidification of delaminated particle dispersion at pH 3. TEM micrographs of particles after immobilization of the cationic complex show scrolls with external diameters of ca. 25-30 nm and wall thicknesses of about 4.5-7.0 nm. The basal spacing (d(040)) of the copper complex intercalated in hexaniobate is about 11.6 A. The estimated composition, [Cu(apip)imH](0.5)HK2Nb6O17.6H2O, indicates that 50% of the negative charge of interlayer I was neutralized by the copper complex. EPR and IR spectra showed that the ligands and the distorted tetragonal structure of the complex were maintained after immobilization into niobate. The reactivity of this new material toward catechol oxidation using hydrogen peroxide as the oxidizing agent was investigated and compared to the activity of the same complex in solution. The heterogeneous catalyst is initially less effective toward the catechol oxidation but with time, the reaction shows a higher catechol conversion (ca. 82%) than the same copper complex in homogeneous media (ca. 75%). A better reactivity of the heterogeneous catalyst may be related to the stabilization of the immobilized catalyst, preventing its degradation during the reaction course. EPR results show that the kinetics of formation of the DMPO/*OH adduct in homogeneous and heterogeneous conditions corresponds to that observed in the catechol oxidation, suggesting that hydroxyl radicals are involved in the reaction mechanism.     

Highly efficient oxidation of alcohols by the system "hydrogen peroxide-[lmn(o)3mnl](pf6)2 (l = 1,4,7-trimethyl-1,4,7-triazacyclononane)-oxalic acid"

Summary The dinuclear manganese(IV) complex [LMn(O)₃MnL](PF₆)₂ (1, L = 1,4,7-trimethyl-1,4,7-triazacyclononane) catalyzes the extremely efficient oxidation of alcohols with hydrogen peroxide at room temperature. Oxalic acid is an obligatory co-catalyst. The oxidation of isopropanol, for example, yields acetone with turnover numbers up to 40000 after 5-10 h in the absence of a solvent. 2-Cyanoethanol was oxidized by this system with somewhat lower efficiency (conversion 70%). The catalytically active cation from salt 1 was obtained in an insoluble form containing a heteropoly anion [Mn₂O₃(TMTACN)₂]₂[SiW₁₂O₄₀]. Oxidation of 2-cyanoethanol using this heterogenized catalyst and oxalic acid gave the oxo-products with the 54% total yield.     

一种复合聚硅氧烷膜的结构与形貌及性能研究

在乙酸乙酯稀溶液中,将氨值为0.6 mmol/g、Mn=14100的聚(N-β-氨乙基-γ-氨丙基甲基硅氧烷-co-二甲基硅氧烷)(ASO)与羧值为0.3 mmol/g、Mn=4048的聚[γ-(β-羧基丙烯酰胺基)丙基甲基硅氧烷-co-十二烷基甲基硅氧烷-co-二甲基硅氧烷](RCAS)共混自组装,可获得一种静电复合的聚硅氧烷ASO/RCAS.以单晶硅和棉纤维织物作载膜基质,用原子力显微镜(AFM)和光电子能谱(XPS)等仪器对ASO/RCAS的膜形貌及应用性能进行了研究.结果表明,由ASO和RCAS复合成的ASO/RCAS,微观形貌呈连续丘陵状凸起,膜厚度为1.501 nm,在2μm×2μm扫描范围内其均方根粗糙度为0.5 nm.将其附着固定在棉纤维表面,ASO/RCAS不仅能引起纤维表面条纹状沟壑消失,而且能使纤维表面的均方根粗糙度从处理前的24.6 nm降低为处理后的11.7 nm.另外,用ASO/RCAS处理的棉织物,其弯曲刚度明显降低、亲水性增加,且表面有舒适的油润感.当ASO与RCAS的质量比为1∶1时,复合聚硅氧烷ASO/RCAS的应用性能最佳.     

The first dinuclear copper(II) and zinc(II) complexes containing novel Bis-TACN: syntheses, structures, and DNA cleavage activities

Two novel binuclear complexes [Cu(2)(L)].(ClO(4))(2) (1) and [Zn(2)(L)].(ClO(4))(2) (2) were synthesized and crystallographically characterized {L = 1(4),5(4)-dimethyl-1(2),5(2)-dihydroxy-1(1,3),5(1,3)-dibenzene-3(1,4),7(1,4)-di-1,4,7-triazacyclononane}. The cation [Cu(2)(L)](2+) structure of 1 is similar to that of [Zn(2)(L)](2+) of 2. The central ion is bridged by the di-phenoxo of L and lies in a close to perfect square pyramidal geometry. 1 and 2 crystallize in the triclinic space group P1. The two complexes effectively promote the cleavage of plasmid DNA in the presence of activating agents at physiological pH and temperature. The pseudo-Michaelis-Menten kinetic parameters k(cat) = 1.61 h(-1), K(m) = 1.35 x 10(-5) M for complex 1 in the presence of mercaptoethanol; k(cat) = 2.48 h(-1), K(m) = 5.5 x 10(-5)M for complex 2 in the presence of hydrogen peroxide were obtained. The mechanism of plasmid DNA cleavage was studied by adding standard radical scavengers. DNA cleavage reaction by the binuclear Zn(II)/H(2)O(2) system is a hydrolytic mechanism.     

以改性Al2O3为载体固定化葡萄糖氧化酶的研究

本文采用吸附和交联、生物和非生物催化剂结合的方法,制得活性高、稳定性好并以Al_2O_3.为载体的固定化葡萄糖氧化酶,其性能优于文献报导的结果.     

Phosphodiester cleavage properties of copper(II) complexes of 1,4,7-triazacyclononane ligands bearing single alkyl guanidine pendants

Three new metal-coordinating ligands, L(1)·4HCl [1-(2-guanidinoethyl)-1,4,7-triazacyclononane tetrahydrochloride], L(2)·4HCl [1-(3-guanidinopropyl)-1,4,7-triazacyclononane tetrahydrochloride], and L(3)·4HCl [1-(4-guanidinobutyl)-1,4,7-triazacyclononane tetrahydrochloride], have been prepared via the selective N-functionalization of 1,4,7-triazacyclononane (tacn) with ethylguanidine, propylguanidine, and butylguanidine pendants, respectively. Reaction of L(1)·4HCl with Cu(ClO(4))(2)·6H(2)O in basic aqueous solution led to the crystallization of a monohydroxo-bridged binuclear copper(II) complex, [Cu(2)L(1)(2)(μ-OH)](ClO(4))(3)·H(2)O (C1), while for L(2) and L(3), mononuclear complexes of composition [Cu(L(2)H)Cl(2)]Cl·(MeOH)(0.5)·(H(2)O)(0.5) (C2) and [Cu(L(3)H)Cl(2)]Cl·(DMF)(0.5)·(H(2)O)(0.5) (C3) were crystallized from methanol and DMF solutions, respectively. X-ray crystallography revealed that in addition to a tacn ring from L(1) ligand, each copper(II) center in C1 is coordinated to a neutral guanidine pendant. In contrast, the guanidinium pendants in C2 and C3 are protonated and extend away from the Cu(II)-tacn units. Complex C1 features a single μ-hydroxo bridge between the two copper(II) centers, which mediates strong antiferromagnetic coupling between the metal centers. Complexes C2 and C3 cleave two model phosphodiesters, bis(p-nitrophenyl)phosphate (BNPP) and 2-hydroxypropyl-p-nitrophenylphosphate (HPNPP), more rapidly than C1, which displays similar reactivity to [Cu(tacn)(OH(2))(2)](2+). All three complexes cleave supercoiled plasmid DNA (pBR 322) at significantly faster rates than the corresponding bis(alkylguanidine) complexes and [Cu(tacn)(OH(2))(2)](2+). The high DNA cleavage rate for C1 {k(obs) = 1.30 (±0.01) × 10(-4) s(-1) vs 1.23 (±0.37) × 10(-5) s(-1) for [Cu(tacn)(OH(2))(2)](2+) and 1.58 (±0.05) × 10(-5) s(-1) for the corresponding bis(ethylguanidine) analogue} indicates that the coordinated guanidine group in C1 may be displaced to allow for substrate binding/activation. Comparison of the phosphate ester cleavage properties of complexes C1-C3 with those of related complexes suggests some degree of cooperativity between the Cu(II) centers and the guanidinium groups.     

Alkene cis-dihydroxylation by [(Me3tacn)(CF3CO2)RuVI O2)]ClO4(Me(3)tacn = 1,4,7-Trimethyl-1,4,7-triazacyclononane): structural characterization of [3 + 2] cycloadducts and kinetic studies

cis-Dioxoruthenium(VI) complex [(Me(3)tacn)(CF(3)CO(2))Ru(VI)O(2)]ClO(4) (1, Me(3)tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) reacted with alkenes in aqueous tert-butyl alcohol to afford cis-1,2-diols in excellent yields under ambient conditions. When the reactions of 1 with alkenes were conducted in acetonitrile, oxidative C=C cleavage reaction prevailed giving carbonyl products in >90% yields without any cis-diol formation. The alkene cis-dihydroxylation and C=C cleavage reactions proceed via the formation of a [3 + 2] cycloadduct between 1 and alkenes, analogous to the related reactions with alkynes [Che et al. J. Am. Chem. Soc. 2000, 122, 11380]. With cyclooctene and trans-beta-methylstyrene as substrates, the Ru(III) cycloadducts (4a) and (4b) [formula; see text] were isolated and structurally characterized by X-ray crystal analyses. The kinetics of the reactions of 1 with a series of p-substituted styrenes has been studied in acetonitrile by stopped-flow spectrophotometry. The second-order rate constants varied by 14-fold despite an overall span of 1.3 V for the one-electron oxidation potentials of alkenes. Secondary kinetic isotope effect (KIE) was observed for the oxidation of beta-d(2)-styrene (k(H)/k(D) = 0.83 +/- 0.04) and alpha-deuteriostyrene (k(H)/k(D) = 0.96 +/- 0.03), which, together with the stereoselectivity of cis-alkene oxidation by 1, is in favor of a concerted mechanism.     

Synthesis, molecular structure, and catalytic potential of the tetrairon complex [Fe4(N3O2-L)4(mu-O)2]4+ (L = 1-carboxymethyl-4,7-dimethyl-1,4,7-triazacyclononane)

The reaction of iron sulfate with 1-carboxymethyl-4,7-dimethyl-1,4,7-triazacyclononane (L) and hydrogen peroxide in aqueous ethanol gives a brown dinuclear complex considered to be [Fe2(N3O-L)2(mu-O)(mu-OOCCH3)] + (1), which converts upon standing in acetonitrile solution into the green tetranuclear complex [Fe4(N3O2-L)4(mu-O)2]4+ (2). A single-crystal X-ray structure analysis of [2][PF6]4.5MeCN reveals 2 to contain four iron(III) centers, each of which is coordinated to three nitrogen atoms of a triazacyclononane ligand and is bridged by one oxo and two carboxylato bridges, a structural feature known from the active center of methane monooxygenase. Accordingly, complex 2 was found to catalyze the oxidative functionalization of methane with hydrogen peroxide in aqueous solution to give methanol, methyl hydroperoxide, and formic acid; the total turnover numbers attain 24 catalytic cycles within 4 h. To gain more insight into the catalytic process, the catalytic potential of 2 was also studied for the oxidation of higher alkanes, cycloalkanes, and isopropanol in acetonitrile, as well as in aqueous solution. The bond selectivities of the oxidation of linear and branched alkanes suggest a ferroxy radical pathway.     

Metal complexes with a new N(4)O(3) amine pendant-armed macrocyclic ligand: synthesis, characterization, crystal structures, and fluorescence studies

The synthesis of a new oxaaza macrocyclic ligand, L, derived from O(1),O(7)-bis(2-formylphenyl)-1,4,7-trioxaheptane and tren containing an amine terminal pendant arm, and its metal complexation with alkaline earth (M = Ca(2+), Sr(2+), Ba(2+)), transition (M = Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+)), post-transition (M = Pb(2+)), and Y(3+) and lanthanide (M = La(3+), Er(3+)) metal ions are reported. Crystal structures of [H(2)L](ClO(4))(2).3H(2)O, [PbL](ClO(4))(2), and [ZnLCl](ClO(4)).H(2)O are also reported. In the [PbL] complex, the metal ion is located inside the macrocyclic cavity coordinated by all N(4)O(3) donor atoms while, in the [ZnLCl] complex, the metal ion is encapsulated only by the nitrogen atoms present in the ligand. pi-pi interactions in the [H(2)L](ClO(4))(2).3H(2)O and [PbL](ClO(4))(2) structures are observed. Protonation and Zn(2+), Cd(2+), and Cu(2+) complexation were studied by means of potentiometric, UV-vis, and fluorescent emission measurements. The 10-fold fluorescence emission increase observed in the pH range 7-9 in the presence of Zn(2+) leads to L as a good sensor for this biological metal in water solution.     

Study of catalase electrode for organic peroxides assays

The catalytic activity of immobilized catalase (EC 1.11.1.6) for two model peroxide compounds (dibenzoyl peroxide and 3-chloroperoxibenzoic acid) in a non-aqueous medium was used to prepare an organic-phase enzyme electrode (OPEE). The enzyme was immobilized within a polymeric film on spectrographic graphite. The amperometric signal of the enzyme electrode in substrate solutions was found to be due to the reduction of oxygen generated in the enzyme layer. The electrode response is proportional to peroxide concentrations up to about 40 microM within the potential range from -450 to -650 mV (vs. Ag/AgCl), and the response time is at most 90 s. The enzyme electrode retains about 35% of its initial activity after a 3-week storage at room temperature.     

Design of a dinuclear nickel(II) bioinspired hydrolase to bind covalently to silica surfaces: synthesis, magnetism, and reactivity studies

Presented herein is the design of a dinuclear Ni(II) synthetic hydrolase [Ni(2)(HBPPAMFF)(μ-OAc)(2)(H(2)O)]BPh(4) (1) (H(2)BPPAMFF = 2-[(N-benzyl-N-2-pyridylmethylamine)]-4-methyl-6-[N-(2-pyridylmethyl)aminomethyl)])-4-methyl-6-formylphenol) to be covalently attached to silica surfaces, while maintaining its catalytic activity. An aldehyde-containing ligand (H(2)BPPAMFF) provides a reactive functional group that can serve as a cross-linking group to bind the complex to an organoalkoxysilane and later to the silica surfaces or directly to amino-modified surfaces. The dinuclear Ni(II) complex covalently attached to the silica surfaces was fully characterized by different techniques. The catalytic turnover number (k(cat)) of the immobilized Ni(II)Ni(II) catalyst in the hydrolysis of 2,4-bis(dinitrophenyl)phosphate is comparable to the homogeneous reaction; however, the catalyst interaction with the support enhanced the substrate to complex association constant, and consequently, the catalytic efficiency (E = k(cat)/K(M)) and the supported catalyst can be reused for subsequent diester hydrolysis reactions.     

CATALASE MIMIC WITH Fe (II) METALLOMICELLE

The effect of Fe (II) metallomicelle as a model of catalase, which was formed by adding surfactants (CTAB, SDS, LSS, Brij35) in Fe (II) -trien complex of molar ratios 1: 500 on the decomposition of hydrogen peroxide was investigated at 20°C and 30°C in pH 10 using KI-color and UV Spectrophotometry. A kinetic model for metallomicellar catalysis was proposed. The association constant of the ternary complex K and the rate constant of the decomposition of hydrogen peroxide k3 were obtained. The results indicate that the metallomicelles making up of Fe (II) metal complex and cationic or nonionic surfactants have obvious catalysis on the decomposition of hydrogen peroxide, but the metallomicelles making up of Fe (II) metal complex and anionic or zwitterionic surfactants have inhibition on this reaction.