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121.
A new organic donor 3‐amino‐6‐dimethylamino‐2‐methyl‐phenazine was introduced to charge‐transfer complex with polyoxometalate. The complex [C15H17N4]4[Mo8O26] ( 1 ) was synthesized by hydrothermal reaction of neutral red chloride (3‐amino‐6‐dimethylamino‐2‐methyl‐phenazine hydrochloride) and (NH4)6[Mo7O24] · 4H2O and was characterized by EPR, element analysis and single crystal x‐ray diffraction. 相似文献
122.
Heterometallic atoms can be incorporated into the Mo
3
IV
trinuclear ion [Mo3S4(H2O)9]4+ to give cuboidal complexes of the kind Mo3MS4, or related edge-linked species {Mo3MS4}2, or corner-shared Mo3S4MS4Mo3 double cubes, depending on the heteroatom used. All of the products formed can be obtained as aqua ions. With four recent additions there are now 15 different heterometal atoms participating in this chemistry from Cr in Group 6 to Bi in Group 15. Preparative procedures, X-ray crystal structures, and distinctive properties including UV-Vis spectra, elution characteristics using Dowexcation exchange chromatography, ICP metal analyses, and the stoichiometries of reactions in which the heterometallic product is oxidized back to [Mo3S4(H2O)9]4+ (with release of the heterometal in an ionic form) are considered.Dedicated to Professor Jiaxi Lu on the occasion of his 80th birthday. 相似文献
123.
The surface structure of Ce adsorbed on a Mo(110) surface was studied by reflection high energy electron diffraction. Five kinds of surface structures were found with different deposition coverages in the submonolayer region. These structures have a common feature that Ce atoms possess a periodicity with double spacing at the atomic rows in the Mo[
10] direction. Observed at 1 ML of Ce coverage was a surface structure related to a deformed fcc Ce(111) plane. 相似文献
124.
二溴羟基苯基荧光酮荧光熄灭法测定微量钼 总被引:9,自引:0,他引:9
本文用荧光熄灭法研究了十溴羟基苯基荧光酮(DBH-PF)-溴化十六烷基三甲铵(CTMAB)-Mo(Ⅵ)体系的测定方法及条件。在0.002~0.008mol/L的H_3PO_4介质中,在CTMAB存在下,钼(Ⅵ)与试剂形成1:2的桔红色络合物,其最大激发波长为470nm和502nm,最大发射波长为520nm。钼在0.03~0.50μg/25ml范围内具有线性关系,检出限为0.03μg/25ml。本法灵敏度高,选择性好,用于检测合金钢中的微量钼,结果满意。 相似文献
125.
The first stages of Co–Ni and Co–Ni–Mo deposition in sulphate–citrate medium at pH 4.0 were analysed. In both cases, the formation of non-hydrogenated nickel on the electrode before alloy deposition was detected by linear sweep voltammetry and inductively coupled plasma mass spectrometry. Co–Ni electrodeposition was anomalous since the Co/Ni ratio in the alloy was higher than the corresponding [Co(II)]/[Ni(II)] ratio in solution. The adsorption of Co(II) over the initial nickel could explain the anomalous codeposition, which persisted with the addition of molybdate to the Co–Ni bath. However, the formation of intermediate molybdenum oxides also took place. A mechanism has been proposed to describe the sequence of steps for Co–Ni–Mo electrodeposition. Under our conditions, the alloy is formed mainly from free Co2+ and Ni2+ cations, whereas molybdate is reduced firstly to molybdenum oxide from MoO4(H3Cit)2− and, secondly, NiCit− catalyses the subsequent reduction to molybdenum metal of the intermediate [MoO2–NiCit−]ads species. 相似文献
126.
A general and selective method for the direct amidation of secondary benzyl alcohols with both sulfonamides and carbamates is described. This method has been applied to a variety of substrates and the reaction proceeded smoothly at room temperature in the presence of 5 mol % molybdenum(V) chloride to give the desired products in good yields. 相似文献
127.
Molybdenum reacted with diethyldithiocarbamate showed a single line at g=1.980 in electron paramagnetic resonance spectrometry at room temperature after reduction by oxalic acid. Molybdenum in 10 μl of urine could be quantitated within 5 min with the detection limit of 50 pg. 相似文献
128.
Emma Thorn-Cs nyi J rg Ulrich Zilles 《Journal of molecular catalysis. A, Chemical》2002,190(1-2):85-100
The structure/property relationship of Schrock-type alkylidene complexes with tungsten and molybdenum as central atoms was investigated. Terminal and, E and Z internal olefins as well as double bond substituted and unsubstituted unsaturated polymers served as metathesis substrates. According to the results obtained, it is possible to choose the optimal catalyst depending on the metathesis substrate and temperature, the central atom plays a decisive role. Examples concerning equilibrium polymerization demonstrate the practical utilization. 相似文献
129.
Arun Kumar Gupta 《Tetrahedron letters》2005,46(24):4171-4174
The exclusive formation of cyclopentenones (via path B) was observed in molybdenum hexacarbonyl (10 mol %) catalyzed Pauson-Khand reactions of 1,6-allenynes under 1 atm of CO (balloon) without any substitutent effect. 相似文献
130.
黄应平 《新疆大学学报(理工版)》1997,14(4):75-77
研究了在表面活性剂存在下,三种新的9-取代苯基荧光酮类试剂与钼(Ⅵ)的显色反应及其光度分析特征,试验结果表明,试剂分子9位上引入的取代基明显影响试剂的配合能力。本文从取代基的电子效应等方面讨论了试剂的结构与性能之间的关系。 相似文献