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991.
992.
《Electroanalysis》2005,17(10):847-856
The electrochemistry of water‐soluble manganese porphyrins (Mn(4‐TMPyP)) has been studied as an electrochemically‐active film on double‐stranded deoxyribonucleic acid (dsDNA) modified electrodes in solutions at various pH. An electrochemical quartz crystal microbalance and cyclic voltammetry were used to study the in situ deposition of DNA on gold disk electrodes, and Mn(4‐TMPyP) (manganese meso‐tetrakis‐(N‐methyl‐4‐pyridyl)porphyrin) deposition on DNA film modified electrodes. MnII(4‐TMPyP) (the reduced form) is more easily deposited on a DNA film than MnIII(4‐TMPyP) (the oxidized form). Electrodeposition of Mn(4‐TMPyP) can be performed in strong basic aqueous solutions, and shows two redox couples with electrochemically active voltammograms. The films can also be produced on glassy carbon, platinum, gold, and transparent semiconductor tin (IV) oxide electrodes. The Mn(4‐TMPyP)/DNA film was electrocatalytically oxidative for hydrazine, hydroxylamine, and SO in a basic aqueous solution through a Mn(IV) species. The electrocatalytic efficiency of MnIV(O)(4‐TMPyP) was observed to be greater than (OH)MnIV(O)(4‐TMPyP). Electrocatalytic oxidation by a Mn(4‐TMPyP) film as a catalyst for hydrazine oxidation is also discussed. This shows a new anodic peak current in the second segment after the positive scan during electrocatalytic oxidation, and is pH dependent. 相似文献
993.
Zhi Hui HE Wen Rui JIN* School of Chemistry Chemical Engineering Shandong University Jinan 《中国化学快报》2002,13(10)
Horseradish peroxidase (HRP) is the archetypal heme peroxidase. The determination of HRP is considerably important in clinical chemistry and analytical biochemistry, because HRP is the commonly used enzyme label for immunological detection systems1. We developed a novel method based on its catalytic reaction. A capillary catalytic reaction system was designed (Figure 1). In the assay, both HRP and H2O2 are injected into the polyacrylamide-coated injection capillary (10) by electromig… 相似文献
994.
I. de Pedro J. M. Rojo M. Insausti J. L. Mesa M. I. Arriortua T. Rojo 《无机化学与普通化学杂志》2005,631(11):2096-2100
The sarkinite, Mn2(OH)AsO4, mineral has been synthesized in laboratory as pure phase under mild hydrothermal conditions. The decomposition process of the hydroxiarsenate compound is strongly dependent on the atmospheric conditions. The results of the thermal treatment in air or argon are quite different. In this way, a new black phase appears in air atmosphere in the 400‐630 °C temperature range whereas under inert atmosphere the structure of Mn2(OH)AsO4 at room temperature is maintained up to 560 °C. The weight loss is attributed to the partial decomposition of Mn2(OH)AsO4 above 400 °C with removal of OH groups and the oxidation of MnII to MnIII that occur simultaneously. Above 650 °C, the structures of the intermediate compounds are broken and the evolution of the inorganic residues gives rise to the formation of arsenates and oxides of MnII and MnIII in inert and air atmospheres. 相似文献
995.
Gelson Manzoni de Oliveira Gleison Antonio Casagrande Eliandro Faoro Ramo Marceli Fernandes Jr. Peter Mayer Ernesto Schulz Lang 《无机化学与普通化学杂志》2003,629(9):1566-1568
[BrMn(CO)5] reacts with benzoylhydrazine in THF occurring substitution of two CO groups by a Metal‐ligand ring to give fac‐[Mn(Br)(CO)3(BHD)]·2THF (BHD = C6H5CONHNH2). The novel compound shows a distorted octahedral arrangement at the manganese atom, with three nearly linear carbonyl ligands in a fac arrangement, illustrating another example that the CO group in position trans to the bromine ligand in [BrMn(CO)5] presents the most intensive metal‐CO backbonding effect of all the CO groups of the parent complex, leading to the formation of a facial (and not meridional) isomer, even in the presence of a bidentate ligand like benzydrazide. X‐ray measures of yellow crystals showed that the title complex belong to space group P21/c, with the asymmetric unit containing one crystallographically independent [Mn(Br)(CO)3(BHD)] complex and two tetrahydrofurane solvate molecules. The new compound represents heretofore the unique occurrence of the complexing single bidentate ligand ‐O=C(Ph)‐N(H)‐N(H)2‐ with an octahedral coordination at the MnI atom supported chiefly by carbonyl groups. 相似文献
996.
《Electroanalysis》2005,17(8):655-661
The first examples of using edge plane pyrolytic graphite electrodes for anodic and cathodic stripping voltammetry (ASV and CSV) are presented, notably the ASV of silver and the CSV of manganese. In the former example, detection limits for silver (based on 3σ) of 8.1 nM and 0.185 nM for 120 s and 300 s accumulation time, respectively, were achievable using the edge plane electrode, which were superior to those observed on glassy carbon, basal plane pyrolytic graphite and boron‐doped diamond electrodes. In the second example, a detection limit for manganese of 0.3 μM was possible which was comparable with that achievable with a boron‐doped diamond electrode but with an increased sensitivity. Comparison of the edge plane pyrolytic graphite electrode with boron‐doped diamond electrodes reveals that the edge plane electrode has comparable detection limits and sensitivities whilst exhibiting a lower signal‐to‐noise ratio and large potential window for use in trace analysis suggesting boron‐doped diamond can be conveniently replaced by edge plane pyrolytic graphite as an electrode material in many applications. 相似文献
997.
Qianling Guo Wenxiang Zhu Shujing Dong Shulan Ma Xi Yan 《Journal of Molecular Structure》2003,650(1-3):159-164
The title calixarene, dimanganese thiacalix[4]arene tetrasulfonate, was prepared and its crystal structure was determined. [Mn(H2O)6]2[thiacalix[4]arene tetrasulfonate]·0.5H2O crystallizes in the monoclinic system, P2(1)/m space group, with a=13.014 (6), b=14.146 (9), c=13.184 (7) Å, β=113.307 (10)°, V=2229 (2) Å3 and Dc=1.710 gcm−3, Z=2. The title calixarene exists in the solid state as bilayer structure. The hydrophobic organic layer consists of thiacalix[4]arene tetrasulfonate in an up-down fashion, whereas, the hydrophilic inorganic layer consists of hexaaquamanganese (II) which is linked to the former through a second-sphere coordination. 相似文献
998.
4,5-Dihydrofuran-3-carbonitriles 3a-i were obtained through oxidative cyclizations of 3-oxo-3-phenylpropanenitrile 1a, 3-oxo-3-thien-2-ylpropanenitrile 1b, 3-(2-furyl)-3-oxopropanenitirle 1c, 3-(1-benzofuran-2-yl)-3-oxopropanenitrile 1d, and 4,4-dimethyl-3-oxopropanenitrile 1e mediated manganese(III) acetate with 1,1-diphenyl-1-butene 2a and 1,2-diphenyl-1-pentene 2b. The treatments of these 3-oxopropanenitriles with 2-thienyl substituted alkenes such as 2-[(E)-2-phenylvinyl]thiophene 2c, 2-[(E)-1-methyl-2-phenylvinyl]thiophene 2d, and 2-(1-phenylvinyl)thiophene 2e formed 5-(2-thienyl)-4,5-dihydrofuran-3-carbonitriles 3j-r in good yields (45-93%). As a result, 2-thienyl substituted alkenes formed products in higher yields than phenyl substituted derivatives. 相似文献
999.
Li‐Na Zhu Yan Ou‐Yang Zhan‐Quan Liu Dai‐Zheng Liao Zong‐Hui Jiang Shi‐Ping Yan Peng Cheng 《无机化学与普通化学杂志》2005,631(9):1693-1697
A novel mixed‐ligand complex {[Mn(azpy)2(dca)(H2O)2](ClO4)(azpy)(H2O)2}n ( 1 ) has been synthesized and characterized by single crystal X‐ray analysis, elemental analysis, IR spectroscopy and variable temperature magnetic measurement. The 4,4′‐azopyridine and dicyanamide ligands are abbreviated as azpy and dca, respectively. The crystal structure of 1 revealed that the 1D covalent bonding chains constructed by μ1,5‐dca bridging the MnII ions are linked together via O–H···N and O–H···O hydrogen bonds and π‐π stacking interactions into a 3D supramolecular structure. V‐shape (bent) water trimers were also found in the structure. The water clusters play an important role in the formation of the 3D supramolecular structure. The determination of the variable temperature magnetic susceptibilities (2–300 K) shows the existence of a very weak antiferromagnetic interaction with a J value of ?0.16 cm?1. 相似文献
1000.
Conrado Camacho Juan C. Matías Belkis Chico Roberto Cao Leissy Gómez Benjamin K. Simpson Reynaldo Villalonga 《Electroanalysis》2007,19(24):2538-2542
Horseradish peroxidase, previously modified with 1‐adamantane moieties, was supramolecularly immobilized on gold electrodes coated with perthiolated β‐cyclodextrin. The functionalized electrode was employed for the construction of an amperometric biosensor device for hydrogen peroxide using 1 mM hydroquinone as electrochemical mediator. The biosensor exhibited a fast amperometric response (6 s) and a good linear response toward H2O2 concentration between 12 μM and 450 μM. The biosensor showed a sensitivity of 1.02 mA/M cm2, and a very low detection limit of 5 μM. The electrode retained 97% of its initial electrocatalytic activity after 30 days of storage at 4 0C in 50 mM sodium phosphate buffer, pH 7.0. 相似文献