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本文研究了两相催化体系中,在CTAB(C_(16)H_(33)NMe_3Br)存在下,水溶性铑-膦配合物RhCl(CO)(TPPTS)_2对1-己烯氢甲酰化反应的催化性能,详细考察了反应温度、压力、膦/铑比等对催化活性的影响。结果表明,在1.0MPa恒压下,反应温度100℃,膦/铑摩尔比为16,H_2:CO=1:1的条件下,1-己烯氢甲酰化的转化频率(TOF)可达到39.8min ̄(-1)。在此反应条件下,有机相和水相容易分离,铑-膦配合物流失到有机相中的量极小。 相似文献
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用固相法首次合成了NdSr_(1-x)M_xNiO_4(M=Ca:0.0≤1.0;M=Ba:0.0≤x≤0.6)系列复合氧化物,并研究了其结构,红外光谱,电学性质和磁学性质。除NdCaNiO以正交晶系结晶外,其它试样的结构均属于四方晶系。IR谱显示随Ca ̄(2+)离子含量的增加,NdSr_(1-x)M_xNiO_4的Ni-O键缩短,Ca ̄(2+)和Ba ̄(2+)引入NdSrNiO_4以取代Sr ̄(2+),使试样由金属性导电转变为半导体性导电;随Ca ̄(2+)含量增加,试样的室温电阻率增大。77~300K磁化率与温度关系曲线显示,所有试样的Ni ̄(3+)都以低自旋状态存在。 相似文献
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(dppe)Rh(μ—CO)2M(CO)3(M=Cr,Mo,W)的合成,表征和催化功能 总被引:1,自引:0,他引:1
合成和表征了(dppe)(Rh(μ-CO)2M(CO3)(M=Cr,Mo,W)异双核金属羰基化合物,考察了SiO2负载的这组配合物催化一氧化碳氢化反应和丙烯氢甲酰化反应的活性和性,记录了催化生氧化碳氢化反应的原位FT-IR谱。 相似文献
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本文报道了以2-(6-甲基-2-苯并噻唑偶氮)-5-二乙氨基酚(MBTAE)作柱前衍生化试剂,在SpherisorbC_8柱上,以甲醇:水=80:20(V/V),含2mmol/LLi_2SO_4和10mmol/LpH5.0醋酸盐缓冲溶液作流动相,反相高效液相色谱分离和测定了Fe ̄(2+)、Co ̄(2+)、Ni ̄(2+)和Cu ̄(2+)。各金属离子的检出限(S/N=3)分别为(pg):Fe ̄(2+)6.40,Co ̄(2-)1.38,Ni ̄(2+)4.47,Cu ̄(2+)7.28。方法用于欧洲标准局,黑麦草标样的分析,所得结果与标准值相符。 相似文献
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G. A. Hiremath P. L. Timmanagoudar S. T. Nandibewoor 《Reaction Kinetics and Catalysis Letters》1998,63(2):403-408
Ruthenium(III) catalyzed oxidation of hexacyanoferrate(II) by periodate in alkaline medium is assumed to occurvia substrate-catalyst complex formation followed by the interaction of oxidant and complex in the rate-limiting stage and yield
the products with regeneration of catalyst in the subsequent fast step. The reaction exhibits fractional order in hexacyanoferrate(II)
and first-order unity each in oxidant and catalyst. The reaction constants involved in the mechanism are derived. 相似文献
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The kinetics and mechanism of Ag(I)-catalyzed oxidation of l-alanine by cerium (IV) in sulfuric acid media have been investigated by titrimetric technique of redox in the temperature range of 298–313 K. It is found that the reaction is of first order with respect to Ce(IV) and l-alanine, and it is of a positive fractional order with respect to Ag(I). It is found that the pseudo first order ([l-alanine] ? [Ce(IV)] ? [Ag(I)]) rate constant k′ increases with the increase of[H+]. The major oxidation product of alanine has been identified as acetaldehyde by an 1H NMR and IR spectroscopy. Under the experimental conditions, the kinetically active species has been found to be Ce4+. Under nitrogen atmosphere, the reaction system can initiate the polymerization of acrylonitrile, indicating generation of free radicals. On the basis of the experimental results, a suitable mechanism has been proposed. The rate constants of the rate-determining step together with the activation parameters were evaluated. 相似文献
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Sabyasachi Ta Milan Ghosh Noor Salam Jayanta Das Manirul Islam Paula Brandão Vítor Félix Jesus Sanmartin Debasis Das 《应用有机金属化学》2020,34(10):e5823
An amide-imine conjugate, (E)-N′-((2-hydroxybenzen-1-yl) methylene)-4-methylbenzohydrazide (H2LPTASAL), derived from 4-methyl-benzoic acid hydrazide (PTA) and 2-hydroxybenzaldehyde is used to prepare Mo (VI), Cu (II) and Fe (III) complexes. The X-ray structurally characterized complexes have been explored as catalyst for amine assisted asymmetric ring opening (ARO) of epoxide, carbon-heteroatom cross-coupling and ethyl benzene oxidation. In addition, their catecholase like activities have thoroughly been investigated. Moreover, the Cu (II) complex selectively recognizes histidine by fluorescence spectroscopy. 相似文献
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Ronald Grigg Daniel M. Cooper Simon McDonald Mohammed A.B. Sarker 《Tetrahedron》2005,61(36):8677-8685
A range of regio- and stereo-selective 1,3-dipolar reactions of imines of α-amino esters, generating polysubstituted prolines, catalysed by silver(I) exchanged zeolites or silver(I) supported on titania, both in combination with DBU, are described. The use of a catalytic amount of silver(I) oxide, Ni(II) complexes and cuprous iodide as catalysts for the cycloaddition reactions are also disclosed. 相似文献
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Cindrić Marina Matković-Čalogović Dubravka Vrdoljak Višnja Kamenar Boris 《Structural chemistry》1998,9(5):353-358
Oxidation of molybdenum(II) thiopivalate and thiobenzoate in the presence of -picoline or pyridine results in the formation of dinuclear molybdenum(V) complexes of the general formulae [Mo2O2(-O)2(-SO4)L4] with L = -picoline or pyridine and [Mo2O2(-O)(-S)(-SO4)L4] with L = -picoline. As determined by X-ray structure analysis, two complexes with -picoline differ in their bridging cores: In one complex, two Mo atoms are doubly bridged through two oxygen atoms; in the other, one Mo atom is doubly bridged through oxygen and sulfur atoms. However, they both crystallize together. The product is solvated with -picoline and water molecules. Molybdenum atoms exhibit distorted octahedral coordinations. The same complexes were prepared also through direct reactions of [Mo2O3(O2CCH3)4] with thiopivalic and thiobenzoic acid in the presence of -picoline or pyridine. The appearance of the oxo-oxygens and sulfido-sulfur as well as sulfato ligand is explained by the molybdenum-catalyzed oxidation of thiocarboxylates. 相似文献
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Serenella Medici Massimiliano Peana Alessio Pelucelli Maria Antonietta Zoroddu 《Molecules (Basel, Switzerland)》2021,26(9)
Rhodium is one of the most used metals in catalysis both in laboratory reactions and industrial processes. Despite the extensive exploration on “classical” ligands carried out during the past decades in the field of rhodium-catalyzed reactions, such as phosphines, and other common types of ligands including N-heterocyclic carbenes, ferrocenes, cyclopentadienyl anion and pentamethylcyclopentadienyl derivatives, etc., there is still lively research activity on this topic, with considerable efforts being made toward the synthesis of new preformed rhodium catalysts that can be both efficient and selective. Although the “golden age” of homogeneous catalysis might seem over, there is still plenty of room for improvement, especially from the point of view of a more sustainable chemistry. In this review, temporally restricted to the analysis of literature during the past five years (2015–2020), the latest findings and trends in the synthesis and applications of Rh(I) complexes to catalysis will be presented. From the analysis of the most recent literature, it seems clear that rhodium-catalyzed processes still represent a stimulating challenge for the metalloorganic chemist that is far from being over. 相似文献
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水热条件下,合成了新的金属有机骨架[Cu(Hbtc)(bmix)0.5]n(1)(H3btc=1,3,5-苯三甲酸,bmix=1,4-二(2-甲基咪唑基-1-亚甲基)苯)。单晶X射线衍射分析表明,该配合物属正交晶系,Pbcn空间群,晶胞参数为a=1.436 30(9) nm,b=1.477 15(11) nm,c=1.543 48(10) nm,V=3.274 7(4) nm3,Z=8。配合物1中,Hbtc2-以四连接方式与铜中心配位,bmix桥连配体进一步修饰网络结构,最终1显示为1个(4,5)节点的三维的网络结构,其Schl?fli 符号为(42·5·62·8)(42·53·63·7·8)。此外还研究了配合物的热稳定性和对光助类芬顿反应降解甲基橙的催化性质。 相似文献
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Ornidazole is an antiparasitic drug having a wide spectrum of activity. Literature survey has revealed that no attention has been paid towards the oxidation of ornidazole with any oxidant from the kinetic and mechanistic view point. Also no one has examined the role of platinum group metal ions as catalysts in the oxidation of this drug. Such studies are of much use in understanding the mechanistic profile of ornidazole in redox reactions and provide an insight into the interaction of metal ions with the substrate in biological systems. For these reasons, the Ru(III)- and Os(VIII)-catalyzed kinetics of oxidation of ornidazole with chloramine-T have been studied in HCl and NaOH media, respectively at 313 K. The oxidation products and kinetic patterns were found to be different in acid and alkaline media. Under comparable experimental conditions, in Ru(III)-catalyzed oxidation the rate law is −d[CAT]/dt = k [CAT]o[ornidazole]ox[H+]−y[Ru(III)]z and it takes the form −d[CAT]/dt = k [CAT]o[ornidazole]ox[OH−]y[Os(VIII)][ArSO2NH2]−z for Os(VIII)-catalyzed reaction, where x, y and z are less than unity. In acid medium, 1-chloro-3-(2-methyl-5-nitroimidazole-1-yl)propan-2-one and in alkaline medium, 1-hydroxy-3-(2-methyl-5-nitroimidazole-1-yl)propan-2-one were characterized as the oxidation products of ornidazole by GC–MS analysis. The reactions were studied at different temperatures and the overall activation parameters have been computed. The solvent isotope effect was studied using D2O. Under identical set of experimental conditions, the kinetics of Ru(III) catalyzed oxidation of ornidazole by CAT in acid medium have been compared with uncatalyzed reactions. The relative rates revealed that the catalyzed reactions are about 5-fold faster whereas in Os(VIII) catalyzed reactions, it is around 9 times. The catalytic constant (KC) has been calculated for both the catalysts at different temperatures and activation parameters with respect to each catalyst have been evaluated. The observed experimental results have been explained by plausible mechanisms. Related rate laws have been worked out. 相似文献
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Lingling Peng 《Journal of organometallic chemistry》2011,696(1):118-122
[RuCl2(p-cymene)]2 efficiently catalyzes the rearrangement of 2-aryl-2-(phenylthio)penta-3,4-dienyl 2,2,2-trichloroacetimidate to afford (Z)-2,2,2-trichloro-N-(4-aryl-1-(phenylthio)penta-2,4-dien-2-yl)acetamide. Ru carbene is assumed as the reactive intermediate in this rearrangement. 相似文献