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1.
Wei Hu Jian-zhang Li Ying Wang Ju Du Chang-wei Hu 《Journal of Dispersion Science and Technology》2013,34(10):1476-1483
The two Schiff base cobalt(II) complexes, CoL1 and CoL2, were synthesized and characterized. The metallomicelle made up of the cobalt(II) complexes and surfactants (CTAB, LSS and Brij35), as mimic peroxidase metalloenzyme, were used in the catalytic oxidation of phenol by H2O2. The mechanism and a kinetic mathematic model of the phenol catalytic oxidation were studied. The acid effect of reaction system, structural effect of the complexes, and effect of temperature on the rate of the phenol oxidation catalyzed by the mimetic peroxidases have been discussed. The results showed that the schiff base cobalt(II) complexes and their metallomicelles as peroxidase mimics exhibit good catalytic activity and similar catalytic character to natural enzyme. 相似文献
2.
Jia‐Qing Xie Guo‐Xu Chen Hua Yan Jun Li Xiao‐Hong Shi 《Journal of Dispersion Science and Technology》2013,34(4):505-510
A dinuclear copper(II) complex [Cu2(oxheel)] was synthesized and its structure was analyzed. This compound was then mixed with a surfactant (Brij35 or LSS) to form a metallomicelle, which would catalyze the phenol oxidation with the hydrogen peroxide (H2O2). The reaction mechanism and the mathematic model for the kinetics of this reaction were proposed, and the effect of the molar ratio between H2O2 and catalyst, of the temperature and of the pH levels on the rate of catalytic reaction were studied. 相似文献
3.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(1):13-20
The rational selection of ligands is vitally important in the construction of coordination complexes. Two novel ZnII complexes, namely bis(acetato‐κO)bis[1‐(1H‐benzotriazol‐1‐ylmethyl)‐2‐propyl‐1H‐imidazole‐κN3]zinc(II) monohydrate, [Zn(C13H15N5)2(C2H3O2)2]·H2O, ( 1 ), and bis(azido‐κN1)bis[1‐(1H‐benzotriazol‐1‐ylmethyl)‐2‐propyl‐1H‐imidazole‐κN3]zinc(II), [Zn(C13H15N5)2(N3)2], ( 2 ), constructed from the asymmetric multidentate imidazole ligand, have been synthesized under mild conditions and characterized by elemental analyses, IR spectroscopy and single‐crystal X‐ray diffraction analysis. Both complexes exhibit a three‐dimensional supramolecular network directed by different intermolecular interactions between discrete mononuclear units. The complexes were also investigated by fluorescence and thermal analyses. The experimental results show that ( 1 ) is a promising fluorescence sensor for detecting Fe3+ ions and ( 2 ) is effective as an accelerator of the thermal decomposition of ammonium perchlorate. 相似文献
4.
5.
Wei Hu Jian-zhang Li Ying Wang Shen-xin Li Jia-qing Xie 《Journal of Dispersion Science and Technology》2013,34(1):88-95
Metallomicelles made from two Schiff base manganese(III) complexes (MnL1 and MnL2) and surfactants (CTAB and Brij35) were used as mimetic peroxidase in the catalytic oxidation of phenol by H2O2. The catalytic activity of the complexes (MnL1 and MnL2) were investigated. The mechanism and a kinetic mathematic model of the phenol catalytic oxidation were also studied. The results show the optimum acidity of the enzyme-like system in the paper is ca. pH 7.0, the optimum temperature which is ca. 35°C and the optimum molar ratio of H2O2 to the complex is ca. 30 in the complexes-H2O2-buffered solution; the Schiff base manganese(III) complexes and their metallomicelles as peroxidase mimics exhibit good catalytic activity and similar catalytic character to natural enzyme. 相似文献
6.
Wei Hu Jian-zhang Li Ju Du Chang-wei Hu 《Journal of Dispersion Science and Technology》2013,34(9):1195-1202
Three novel cobalt(II) complexes of the benzoaza-15-crown-5 Schiff base, CoL1, CoL2, and CoL3 were synthesized and characterized. Metallomicelles made from CoL and surfactants (CTAB, LSS, and Brij35) were used as mimetic peroxidase in the catalytic oxidation of phenol by H2O2. For comparison, the catalytic activity of the complexes (CoL1, CoL2, and CoL3) were also investigated. The mechanism and a kinetic mathematic model of the phenol catalytic oxidation were studied. The acid effect of reaction system, structural effect of the complexes, and effect of temperature on the rate of the phenol catalytic oxidation by the mimetic peroxidase were discussed. The results show that the Schiff base cobalt(II) complexes and their metallomicelles as peroxidase mimics exhibit good catalytic activity and similar catalytic character to natural enzyme. 相似文献
7.
Catalytic activity of nickel(II), copper(II) and oxovanadium(II)‐dihydroindolone complexes towards homogeneous oxidation reactions 下载免费PDF全文
Mohamed Shaker S. Adam 《应用有机金属化学》2018,32(4)
Three novel paramagnetic metal complexes (MH2ID) of Ni2+, Cu2+ and VO2+ ions with 3‐hydroxy‐3,3’‐biindoline‐2,2’‐dione (dihydroindolone, H4ID) were synthesized and characterized by different spectroscopic methods. The ligand (H4ID) was synthesized via homocoupling reaction of isatin in presence of phenylalanine in methanol. Complexation of low valent Ni2+, Cu2+ ions and high valent VO2+ ions with H4ID carried out in 1: 2 molar ratios. A comparison in the catalytic potential of paramagnetic complexes of low and high valent metal ion was explored in the oxidation processes of cis‐cyclooctene, benzyl alcohol and thiophene by an aqueous H2O2, as a green terminal oxidant, in the presence and absence of acetonitrile, as an organic solvent, at 85 °C. NiH2ID, CuH2ID and VOH2ID show good catalytic activity, i.e. good chemo‐ and regioselectivity. VOH2ID has the highest catalytic potential compared to both Ni2+‐ and Cu2+‐species in the same homogenous aerobic atmosphere. Catalytic oxidation of other alkenes and alcohols was also studied using NiH2ID, CuH2ID or VOH2ID as a pre‐catalyst by an aqueous H2O2. A mechanistic pathway for those oxidation processes was proposed. 相似文献
8.
Filiz Ercan Orhan Atakol Cengiz Arc Ingrid Svoboda Hartmut Fuess 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):m193-m196
The title compounds, bis(dimethylformamide)‐1κO,3κO‐bis{μ‐2,2′‐[2,2′‐dimethylpropane‐1,3‐diylbis(nitrilomethylidyne)]diphenolato}‐1κ4N,N′,O,O′:2κ2O,O′;2κ2O,O′:3κ4N,N′,O,O′‐di‐μ‐nitrito‐1:2κ2N:O;2:3κ2O:N‐dinickel(II)cobalt(II), [CoNi2(NO2)2(C19H22N2O2)2(C3H7NO)2], (I), ‐copper(II), [CuNi2(NO2)2(C19H22N2O2)2(C3H7NO)2], (II), and ‐manganese(II), [MnNi2(NO2)2(C19H22N2O2)2(C3H7NO)2], (III), consist of centrosymmetric linear heterotrinuclear metal complexes. The three complexes are isostructural. There are three bridges across the Ni–M atom pairs (M is Co2+, Cu2+ or Mn2+) in each complex, involving two O atoms of a μ‐N,N′‐bis(salicylidene)‐2,2′dimethyl‐1,3‐propanediaminate ligand and an N—O moiety of a μ‐nitrito group. The coordination sphere around each metal atom, whether Co2+, Cu2+, Mn2+ or Ni2+, can be described as distorted octahedral. The Ni?M distances are 2.9988 (5) Å in (I), 2.9872 (5) Å in (II) and 3.0624 (8) Å in (III). 相似文献
9.
Sevim Hamamci Alisir Necmi Dege Recep Tapramaz 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(4):388-397
Three new diclofenac‐based copper(II) complexes, namely tetrakis{μ‐2‐[2‐(2,6‐dichloroanilino)phenyl]acetato‐κ2O:O′}bis(methanol‐κO)copper(II), [Cu2(μ‐dicl)4(CH3OH)2] ( 1 ), bis{2‐[2‐(2,6‐dichloroanilino)phenyl]acetato‐κ2O,O′}bis(1‐vinyl‐1H‐imidazole‐κN3)copper(II), [Cu(dicl)2(vim)2] ( 2 ), and bis{2‐[2‐(2,6‐dichloroanilino)phenyl]acetato‐κ2O,O′}bis(1H‐imidazole‐κN3)copper(II), [Cu(dicl)2(im)2] ( 3 ) [dicl is diclofenac (C14H10Cl2NO2), vim is 1‐vinylimidazole (C5H6N2) and im is imidazole (C3H4N2)], have been synthesized and characterized by elemental analysis, FT–IR spectroscopy, thermal analysis and single‐crystal X‐ray diffraction. X‐ray diffraction analysis shows that complex 1 consists of dimeric units in which the dicl ligand exhibits a bidentate syn,syn‐μ2 coordination mode linking two copper(II) centres. Complexes 2 and 3 have mononuclear units with the general formula [Cu(dicl)2L2] (L is vim or im) in which the CuII ions are octahedrally coordinated by two L and two dicl chelating ligands. The L and dicl ligands both occupy the trans positions of the coordination octahedron. The different coordination modes of dicl in the title complexes were revealed by Fourier transform IR (FT–IR) spectroscopy. The spin matching between the copper(II) centres in the dimeric [Cu2(μ‐dicl)4(CH3OH)2] units was also confirmed by magnetic data to be lower than the spin‐only value and electron paramagnetic resonance (EPR) spectra. The thermal properties of the complexes were investigated by thermogravimetric (TG) and differential thermal analysis (DTA) techniques. 相似文献
10.
A Kinetic Study of Phenolic Oxidation by H2O2 Using the Schiff Base Complexes As Mimetic Peroxidases
Xie Jia-qing Li Jian-zhang Meng Xiang-guang Hu Chang-wei Zeng Xian-cheng Li Shen-xin 《Transition Metal Chemistry》2004,29(4):388-393
The Schiff base complexes containing a transition metal ion, CoII and CuII, were used as mimetic peroxidase in the catalytic oxidation of phenol by H2O2. The characteristic spectra of the Schiff base complexes in H2O2-buffered solution were recorded and analyzed, respectively. The mechanism and the kinetic mathematic model of the phenol catalytic oxidation were studied. The results showed that the Schiff base complexes containing the transition metal ion, CoII and CuII, as peroxidase mimics exhibited good catalytic activity and the character of the peroxidase in the catalytic oxidation of phenol by H2O2 under different conditions. 相似文献
11.
The tetradentate Schiff-base ligands, N,N′-bis(salicylidene)-ethylenediamine (Salen), N,N′-bis(salicylidene) butylenediamine (Salbut), and N,N′-bis(salicylidene)-o–phenylenediamine, (sal-o-phen) are very strongly sorbed by cation exchange resin (Dowex-50W) with Fe2+ ions as a counter ion, forming stable complexes. The kinetics of the catalytic decomposition of H2O2 using these complexes was studied in ethanolic medium. The reaction was first-order with salen and sal-o-phen and second-order with salbut with respect to [H2O2]. The rate of the H2O2 decomposition increased either from salen to salbut or from salen to sal-o-phen. Also, the k (per g dry resin) values decreased with increasing both the particle size and the degree of resin cross-linkage. The active species formed at the beginning of the reaction, had an inhibiting effect on the reaction rate. The corresponding activation parameters were calculated from a least-squares fit of the temperature dependence of the rate constant. A reaction mechanism is proposed. © 1994 John Wiley & Sons, Inc. 相似文献
12.
Vratislav Langer Pavol Mach Dalma Gyepesov Lucia Andrezlov Mria Kohútov 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(11):m326-m328
In the structure of trans‐bis(ethanol‐κO)tetrakis(1H‐imidazole‐κN3)copper(II) bis[μ‐N‐(2‐oxidobenzylidene)‐D,L‐glutamato]‐κ4O1,N,O2′:O2′;κ4O2′:O1,N,O2′‐bis[(1H‐imidazole‐κN3)cuprate(II)], [Cu(C3H4N2)4(C2H6O)2][Cu2(C15H14N3O5)2], both ions are located on centres of inversion. The cation is mononuclear, showing a distorted octahedral coordination, while the anion is a binuclear centrosymmetric dimer with a square‐pyramidal copper(II) coordination. An extensive three‐dimensional hydrogen‐bonding network is formed between the ions. According to B3LYP/6–31G* calculations, the two equivalent components of the anion are in doublet states (spin density located mostly on CuII ions) and are coupled as a triplet, with only marginal preference over an open‐shell singlet. 相似文献
13.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(2):139-145
Three new manganese(II), lead(II) and cadmium(II) coordination complexes have been prepared by reaction of N‐(1H‐tetrazol‐5‐yl)cinnamamide (HNTCA) with divalent metal salts (MnCl2, PbCl2 and CdCl2) in a mixed‐solvent system, affording mononuclear to trinuclear structures namely, bis(methanol‐κO)bis[5‐(3‐phenylprop‐2‐enamido)‐1H‐1,2,3,4‐tetrazol‐1‐ido‐κ2N1,O]manganese(II), [Mn(C10H8N5O)2(CH3OH)2], (1), bis[μ‐5‐(3‐phenylprop‐2‐enamido)‐1H‐1,2,3,4‐tetrazol‐1‐ido]‐κ3N1,O:N2;κ3N2:N1,O‐bis{aqua[5‐(3‐phenylprop‐2‐enamido)‐1H‐1,2,3,4‐tetrazol‐1‐ido‐κ2N1,O]lead(II)}, [Pb2(C10H8N5O)4(H2O)2], (2), and hexakis[μ2‐5‐(3‐phenylprop‐2‐enamido)‐1H‐1,2,3,4‐tetrazol‐1‐ido‐κ3N1,O:N2]tricadmium(II), [Cd3(C10H8N5O)6], (3). The structures of these three compounds reveal that the nature of the metal ions and the side groups of the organic building blocks have a significant effect on the structures of the coordination compounds formed. Intermolecular hydrogen bonds link the molecules into two‐dimensional [complex (1)] and three‐dimensional hydrogen‐bonded networks. Complexes (2) and (3) show significant fluorescence, while complex (1) displays no fluorescence. 相似文献
14.
D‐glucosamine Schiff base N‐(2‐deoxy‐β‐D‐glucopyranosyl‐2‐salicylaldimino) and its Cu(II) and Zn(II) complexes were synthesized and characterized. The hydrolysis of p‐nitrophenyl picolinate (PNPP) catalyzed by ligand and complexes was investigated kinetically by observing the rates of the release of p‐nitrophenol in the aqueous buffers at 25°C and different pHs. The scheme for reaction acting mode involving a ternary complex composed of ligand, metal ion, and substrate was established and the reaction mechanisms were discussed by metal–hydroxyl and Lewis acid mechanisms. The experimental results indicated that the complexes, especially the Cu(II) complex, efficiently catalyzed the hydrolysis of PNPP. The catalytic reactivity of the Zn(II) complex was much smaller than the Cu(II) complex. The rate constant kN showing the catalytic reactivity of the Cu(II) complex was determined to be 0.299 s?1 (at pH 8.02) in the buffer. The pKa of hydroxyl group of the ternary complex was determined to be 7.86 for the Cu(II) complex. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 345–350, 2002 相似文献
15.
Halis
lmez Cengiz Arc Okan Zafer Yeilel 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(6):m240-m242
In the title complex, mer‐diaqua[2,6‐dioxo‐1,2,3,6‐tetrahydropyrimidine‐4‐carboxylato(2−)]bis(1H‐imidazole‐κN3)cobalt(II), [Co(C5H2N2O4)(C3H4N2)2(H2O)2], the CoII ion is coordinated by a deprotonated N atom and the carboxylate O atom of the orotate ligand, two imidazole N atoms and two aqua ligands in a distorted octahedral geometry. The title complex exists as discrete doubly hydrogen‐bonded dimers, and a three‐dimensional network of O—H...O and N—H...O hydrogen bonds and weak π–π interactions is responsible for crystal stabilization. 相似文献
16.
Di‐Chang Zhong Hua‐Bin Guo Ji‐Hua Deng Ping Lian Xu‐Zhong Luo 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(2):152-154
Single‐crystal X‐ray diffraction analysis of poly[bis(μ2‐5‐carboxy‐2‐propyl‐1H‐imidazole‐4‐carboxylato‐κ3N3,O4:O5)copper(II)], [Cu(C8H9N2O4)2)]n, indicates that one carboxylic acid group of the 2‐propyl‐1H‐imidazole‐4,5‐dicarboxylic acid (H3PDI) ligand is deprotonated. The resulting H2PDI− anion, acting as a bridge, connects the CuII cations to form a two‐dimensional (4,4)‐connected layer. Adjacent layers are further linked through interlayer hydrogen‐bond interactions, resulting in a three‐dimensional supramolecular structure. 相似文献
17.
Lei Guo Jia‐Qun Li Yu‐Ting Xie Chu‐Qin Lu Jian‐Zhong Wu 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(5):428-431
In the coordination polymer catena‐poly[[[diaqua[5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ2N3,O4]lead(II)]‐μ‐5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ3N3,O4:N2] dihydrate], {[Pb(C10H6N3O4)(H2O)2]·2H2O}n, the two 5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylate ligands have different coordination modes, one being terminal and the other bridging. The bridging ligand links PbII cations into one‐dimensional coordination polymer chains. The structure is also stabilized by intra‐ and interchain π–π stacking interactions between the pyridine rings, resulting in the formation of a two‐dimensional network. Extensive hydrogen‐bonding interactions lead to the formation of a three‐dimensional supramolecular network. 相似文献
18.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(27):7887-7890
A dicopper(II) complex, stabilized by the bis(tpa) ligand 1,2‐bis[2‐[bis(2‐pyridylmethyl)aminomethyl]‐6‐pyridyl]ethane (6‐hpa), [Cu2(μ‐OH)(6‐hpa)]3+, was synthesized and structurally characterized. This complex catalyzed selective hydroxylation of benzene to phenol using H2O2, thus attaining large turnover numbers (TONs) and high H2O2 efficiency. The TON after 40 hours for the phenol production exceeded 12000 in MeCN at 50 °C under N2, the highest value reported for benzene hydroxylation with H2O2 catalyzed by homogeneous complexes. At 22 % benzene conversion, phenol (95.2 %) and p ‐benzoquinone (4.8 %) were produced. The mechanism of H2O2 activation and benzene hydroxylation is proposed. 相似文献
19.
Stefan Haslinger Alexander Pthig Mirza Cokoja Fritz E. Kühn 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(12):1096-1099
Iron is of interest as a catalyst because of its established use in the Haber–Bosch process and because of its high abundance and low toxicity. Nitrogen‐heterocyclic carbenes (NHC) are important ligands in homogeneous catalysis and iron–NHC complexes have attracted increasing attention in recent years but still face problems in terms of stability under oxidative conditions. The structure of the iron(II) complex [1,1′‐bis(pyridin‐2‐yl)‐2,2‐bi(1H‐imidazole)‐κN3][3,3′‐bis(pyridin‐2‐yl‐κN)‐1,1′‐methanediylbi(1H‐imidazol‐2‐yl‐κC2)](trimethylphosphane‐κP)iron(II) bis(hexafluoridophosphate), [Fe(C17H14N6)(C16H12N6)(C3H9P)](PF6)2, features coordination by an organic decomposition product of a tetradentate NHC ligand in an axial position. The decomposition product, a C—C‐coupled biimidazole, is trapped by coordination to still‐intact iron(II) complexes. Insights into the structural features of the organic decomposition products might help to improve the stability of oxidation catalysts under harsh conditions. 相似文献
20.
The electrocatalytic oxidation of hydrazine (N2H4) by TEMPOL on a glassy carbon electrode has been studied. The kinetic parameters of the electrode reaction were measured and the electrocatalytic reaction mechanism for the electrooxidation of hydrazine in the presence of TEMPOL was proposed. TEMPOL undergoes a reversible single electron transfer process at a glassy carbon electrode (GCE) at pH 1.2–8.0, and the electrochemical oxidation of N2H4 at a GCE can be catalyzed by TEMPOL. The catalytic current is affected by the concentration of catalyst and pH. The overall number of electrons involved in the catalytic oxidation of N2H4 and the number of electrons involved in the rate determining step (rds) are 4 and 1, respectively. The catalytic oxidation obeys the first-order kinetics with respect to N2H4. The proposed mechanism is consistent with the experimental data, and a cation intermediate [> N---O---N2H4+], formed by reaction of oxoammonium salt with N2H4, is involved in the reaction. 相似文献