976 resultados para Gc-eag
Resumo:
The binuclear complex [Ni(oxae)Ni(phen)2](ClO4)(2) . H2O (oxae=N,N'bis(2-aminoethyl) oxamido dianion, phen = 1, 10-phenanthroline) was prepared from the planar monomeric complex Ni(oxae) and characterized through analytical and spectroscopic measurements. The structure of [Ni(oxae)Ni(phen)(2)] (ClO4)2 . 3H(2)O was investigated by single-crystal X-ray analysis. The complex has an extended oxamido-bridged structure and consists of two nickel(II) ions, one of them in a square planar environment and another in a distorted octahedral environment. The Ni-Ni distance is 5.267 Angstrom.
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The electrochemical behavior of catechol, hydroquinone and resorcinol on GC and PPy/GC electrode surface were studied by CV and RDE method. The results indicated that these three substance could be oxidized electrocatalytically on PPy film electrode. The possibility of fabrication of amperometric electrochemical sensor for catechol was also studied.
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作者改进了气提法富集水中痕量挥发性有机物装置。研究了实验条件对水中痕量有机物富集的影响,并确定了最佳富集条件。以气提法富集气相色谱/质谱法(GC/MS)测定了水样中痕量挥发性有机物,取得了满意的结果。
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LnCl3 (Ln = Nd, Er) reacts with K2C8H8 to yield the complex (C8H8)LnCl.2THF, which reacts with K(2,4-C7H11) (2,4-C7H11 = 2,4-dimethylpentadienyl) to form (C8H8)Ln(2,4-C7H11).THF. The compound (C8H8)Nd(2,4-C7H11).THF(1) crystallizes from the mixed solvent
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The reaction of lanthanide trichlorides with sodium tetrahydrofurfurylcyclopentadienyl in THF afforded bis(tetrahydrofurfurylcyclopentadienyl)lanthanide chloride complexes (C4H7OCH2C5H4),LnCl (Ln = Nd, Gd, Dy, Yb). All of the complexes were characterized
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Tricyclopentadienyl cerium tetrahydrofuranate (THF) was prepared by the reaction of (NH4)2Ce(NO3)6 with sodium cyclopentadienide(C5H5Na) in THF at molar ratio of 1:6 to give a brown crystal of (eta5-C5H5)3Ce.OC4H8; tricyclopentadienyl erbium tetrahydrofur
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Polypyrrole doped with p-toluenesulfonate was electropolymerized onto highly oriented pyrolytic graphite (HOPG), glassy carbon (GC) and Pt electrode surfaces under the same experimental conditions. The resulting films were studied by scanning tunneling m
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{(C8H8)Dy[mu-OCH2(CH2)2CH=CH2](THF)}2 was prepared by the reaction of (C8H8)DyCl(THF)n with CH2=CH(CH2)2CH2ONa in THF and characterized by spectroscopic, analytical and crystallographic methods. Its crystal structure shows that the complex is a dimer with
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Me4C2(C5H4MgCl)2(THF) (THF = tetrahydrofuran) reacts with anhydrous SmCl3 in THF to give [Me4C2CP2SMCl.THF]2. The molecule is a dimer. Sm1 and Sm2 are bridged unsymmetrically by two chlorine atoms [Sm(1)-CI(1) 2.787(2), Sm(1)-Cl(2) 2.848(2), Sm(2)-Cl(1) 2
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A novel framework material, Zn-2(HPO4)(3).H3NCH2CH2NH3, has been synthesised and its crystal structure determined by single crystal X-ray diffraction.
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Brown crystalline tricyclopentadienyl cerium tetrahydrofuranate (THF) complex (eta5-C5H5)3Ce(THF) was prepared by the reaction of (NH4)2Ce(NO3)6 with sodium cyclopentadienide (C5H5Na) in THF at molar ratio of 1:6. ErCl3.4THF reacts with potassium cyclooct
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利用扫描隧道显微镜(STM)研究了高定向热解石墨(HOPG)和玻璃碳电极(GC)表面的性质,并对修饰钻卟啉后的表面形貌变化进行了探讨.结合修饰钴卟啉前后的循环伏安结果和STM形貌图,讨论了电极表面的结构对分子氧的电催化还原反应的影响.从微观角度阐述了GC电极对氧的电催化还原活性明显高于HOPG电极的内在因素,为修饰电极的表面性能研究提供了经验.
Resumo:
A tetrahydrofurfurylcyclopentadienyl sodium tetrahydrofuranate complex was prepared by the reaction of tetrahydrofurfurylcyclopentadiene with metallic sodium in THF. Its crystal structure was determined by X-ray analysis. In the crystal. the tetrahydrofuranate complex C4H7OCH2C5H4Na . THF adopts a puckered chain structure with an eta5-(C4H7OCH2)C5H4 ring connected by a bridging Na(THF) unit. The oxygen in the eta5-(C4H7OCH2)C5H4 ring is coordinated to the sodium atom.
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In this paper, the electrochemical behavior of vitamin B-12, ie cyanocobalamin (abbr. VB12) in a weak acidic aqueous solution and adsorbed on glassy carbon (GC) surface (abbr. VB12(ad)/GC) in different pH buffer solutions have been described by using cyclic voltammetry (cv). It is found that VB12 and VB12(ad)/GC exhibit catalytic activity for the electroreduction of O2 according to two reduction peaks at -0.50 and -1.00 V vs. sce; but their electrocatalytic activity is very unstable. Based on the method of hydrodynamic amperometry [B. Miller and S. Bruckenstein, J. electrochem. Soc. 117, 1033 (1970)], some kinetic parameters for the electrocatalytic reduction of O2 by VB12(ad)/GC have been determined rapidly by using a linear rotation-scan method [Rongzhong Jiang and Shaojun Dong, Electrochim. Acta 35, 1451 (1990)]. These kinetic parameters indicate that the reduction of O2 on VB12(ad)/GC gives water predominantly in both potential ranges which correspond to those two reduction peaks. Possible reaction mechanisms have been suggested.
Resumo:
A multi-cylinder microelectrode coupled with a conventional glassy carbon disc electrode (MCM/GC) was prepared and characterized using cyclic voltammetry and chronoamperometry. It was demonstrated that in the same way as one observed a steady-state current at closely spaced microelectrodes when redox recycling takes place, the same effect can be obtained with the MCM/GC device. The experimental results obtained with K3Fe(CN)6 solutions were compared with a previously developed theory. Further, it was demonstrated that with a carbon fibre MCM/GC device, the voltammetric behaviour of dopamine is greatly improved by virtue of redox recycling, hence giving high sensitivity. The steady-state collection current was linearly related to dopamine concentration in the range 1 X 10(-4) to 5 x 10(-7) Mol l-1, and the detection limit was 2 x 10(-7) mol l-1. The influence of coexisting ascorbic acid was also investigated. This device was applied successfully in the determination of dopamine hydrochloride in pharmaceutical preparations.