Y沸石和多级孔Y沸石封装CuPhen配合物催化性能的比较

选用常规Y沸石和经后处理法制备的多级孔Y沸石为主体,采用自由配体法将铜菲咯啉(CuPhen)配合物封装在不同Y沸石中,制备了CuPhen/Y复合催化材料。采用X射线衍射、TEM、紫外-可见光谱、N_2吸附-脱附、ICP和TG等手段对所制备复合催化材料的物化性质进行了较为详细的表征,并对封装在不同Y沸石主体中的铜配合物在不同尺寸大小反应底物中的催化氧化性能进行了比较研究。结果表明,在以双氧水为氧化剂的反应体系中,封装于多级孔Y沸石中的铜配合物在不同环烷烃氧化反应中的催化活性均高于封装在常规Y沸石中的催化活性,体现出多级孔Y沸石更为优越的主体性能。此外,同封装于常规Y沸石中的铜配合物一样,封装在多级孔Y沸石主体中的金属配合物催化剂也具有良好的稳定性。     

过渡金属配合物催化的二氧化碳的固定*

综述了利用过渡金属配合物和二氧化碳的配位及插入反应实现二氧化碳固定的基本方法、原理及其研究现状。     

过渡金属络合物催化乙烯齐聚

综述了乙烯齐聚的最新成果,重点阐述了用于乙烯齐聚的新型催化剂,讨论了烯烃高聚与齐聚催化剂的关系,烯烃高聚与齐聚的反应机理相同,。差别主要在于烯烃插入与β－H消除反应的速率,第IV副族金属络合物主要催化乙烯齐聚,第Ⅲ副族金属主要催化乙烯高聚,改变茂金属催化体系的助催化剂和反应条件可得到齐聚产物,选择体积较小配体的第Ⅷ族金属络合物,有利于β－H消除得到齐聚产物。     

Gas Chromatography of Transition Metal Salicylaldimine Complexes

Abstract

The stability and ease of formation of some neutral salicylaldimine transition metal complexes has suggested that they may be gas chromatographed and find analytical applications. Thermal an of some bidentate Ni(II), Cu(II) and Zn(II) salicylaldimine comp has shown them to be thermally stable and volatile. Observations the gas chromatographic separation of some of these chelates is described, their favorable properties allow elution from glass a stainless steel columns with minimal decomposition under favorable conditions.     

三核过渡金属配合物在催化反应中的研究进展

多核过渡金属配合物作为一类广泛应用的均相催化剂,其设计灵感往往来自天然酶的多金属活性位点所发挥的重要作用.目前,三核金属配合物作为活化小分子的多金属催化剂受到了广泛的关注.为深入理解三核过渡金属配合物在催化反应中作用特点,对近年报道的代表性三核过渡金属配合物按金属中心进行分类,并对配体环境形成特点及催化应用进行综述.从金属中心出发,讨论了三核过渡金属配合物的几何结构和电子特征;从配体环境出发,总结了关联三个独立的金属位点的配位环境特征;在催化应用方面,重点综述了三核过渡金属配合物在涉及特定化学键活化反应的催化作用机制,最后对三核过渡金属配合物的催化应用前景进行展望.     

Boosting Size‐Selective Hydrogen Combustion in the Presence of Propene Using Controllable Metal Clusters Encapsulated in Zeolite

A strategy is presented for making metal clusters encapsulated inside microporous solids selectively accessible to reactant molecules by manipulating molecular sieve size and affinity for adsorbed molecules. This expands the catalytic capabilities of these materials to reactions demanding high selectivity and stability. Selective hydrogen combustion was achieved over Pt clusters encapsulated in LTA zeolite (KA, NaA, CaA) in a propene‐rich mixture obtained from propane dehydrogenation, showing pore‐size dependent selectivity and coking rate. Propene tended to adsorb at channels or external surfaces of zeolite, interfering the diffusion of hydrogen and oxygen. Tailoring the surface of LTA zeolite with additional alkali or alkaline earth oxides contributed to narrowing zeolite pore size and their affinity for propene. The thus‐modified Pt@KA catalyst displayed excellent hydrogen combustion selectivity (98.5 %) with high activity and superior anti‐coking and anti‐sintering properties.     

Influence of Encapsulation on The Mechanism of Thermal Destruction of Cyanide Transition Metal Complexes

The results of investigation of the influence of encapsulation on the mechanism of thermal decomposition of cyanide transition metal complexes, based on data obtained by methods of differential thermal analysis (inert atmosphere) and thermodesorption (mass-spectral monitoring of gaseous products) are represented. It was established, that encapsulation of cyanide iron(II) and cobalt(III) complexes in faujasite type zeolite results in the hydrolytic mechanism of thermal destruction of complexes, unlike to bulk analogues, which is determined by essential decreasing of the temperature of complex anions encapsulated destruction beginning, up to temperatures while zeolite water molecules are saved; the gaseous products of thermal destruction composition is determined by the peculiarities of localization of cations of different nature in inclusion compounds. This revised version was published online in August 2006 with corrections to the Cover Date.     

氮配位过渡金属配合物在硅氢加成反应中的应用研究

氮配位过渡金属配合物在近十几年来得到迅速的发展。 通过设计不同的含氮配体与不同过渡金属进行配位形成的氮配位过渡金属配合物,在硅氢加成反应中有很大应用研究价值。本文综述了氮配位铑、铁、铼、钴、锌等过渡金属配合物在酮或者烯烃的硅氢加成反应中的新进展。二 NFDA1 唑啉及二氢吡咯等含氮配体的优化设计必将大大促进含氮铁、铼、钴配合物在酮或者亚胺的硅氢加成反应中的应用。     

红霉素A肟与过渡金属配合物的合成、表征及其抑菌活性

红霉素A肟(HL)与MAc_2·nH_2O(M＝Cu,Zn,Co和Ni)反应,合成了4个新的配合物ML_2,其结构和性能经IR,摩尔电导,XRD,DTA-TGA及倒置生物显微镜表征.研究了ML_2对大肠杆菌(A),枯草芽孢杆菌(B),金葡萄球菌(C)及沙门氏菌(D)的生物活性,并与HL和M(Ac)_2·nH_2O进行了比较,结果表明4个配合物对A～D的抑菌效果均比HL和M(Ac)_2·nH_2O好.     

Hydrosilylation Of Heterocyclic Aldimines Catalyzed By Transition Metal Complexes

The addition of triethylsilane to O- and S- heterocyclic Schiff bases in the presence of Rh, Pd, Pt, and Ir complexes has been studied. A series of the corresponding amines has been synthesized using the most active catalysts, which were the dimeric, monovalent complexes [Rh(1,5-cyclooctadiene)Cl]₂ and [Pd(allyl)Cl]₂.     

过渡金属配合物催化炔烃和亲核试剂的羰化反应

羰化反应(氢甲酰化反应、羰化羧酸化反应、羰化酯化反应、羰化酰胺化反应等)是制备醛(/醇)、羧酸、羧酸酯、酰胺等高附加值含氧羰基化合物有效的途径,具有反应原子经济性高、目标羰基化合物选择性高、反应条件较氧化过程更温和可控的优势.羰化反应的原料包括烯烃、炔烃、卤代烃、醇等有机化合物.其中,在过渡金属催化剂作用下,炔烃与不同...     

1,4,7-三氮杂环癸烷过渡金属配合物的合成与结构表征

以十元环大环三胺配体1,4,7-三氮杂环癸烷(tacd)为主配体,分别与钴、镍、铜和锌的顺丁烯二酸盐和己二酸盐进行反应,得到了8种含有双大环的单核配合物,利用元素分析,红外光谱以及热重分析等手段对它们的结构进行了表征.结果表明这八种配合物具有类似的配位结构.     

Characterizations and Catalytic Properties of Transition Metal Ions Incorporated in Mesoporous Materials

Mesoporous materials typified by MCM-41 possess well-ordered mesoporous channels with controllable pore sizes from 2-30 nm, and are expected as desirable materials for catalysis.However, silicious mesoporous materials generally do not have sufficient intrinsic catalytic activities.Thus many studies have focused on introducing catalytically active sites. It is expected that different synthetic methods would result in different coordination structures of metal cations introduced in MCM-41, and thus different catalytic properties in catalytic reactions. The author's group has used two methods, i.e., direct hydrothermal synthesis (DHT) and template-ion exchange (TIE), for the syntheses of V-, Fe-, and Cr-MCM-41 and applied them as catalysts to selective oxidations of hydrocarbons. This paper highlights the characterizations of the coordination structures of these metal cations introduced into MCM-41 by the DHT and the TIE methods, and the structural-property relationships of these metal ion-containing MCM-41 materials in selective oxidation reactions.MCM-41 was prepared by hydrothermal synthesis using hexadecyltrimethylammonium bromide and sodium silicate as the sources of template and silicon, respectively. In the DHT method, metal cations were directly added into the synthesis gel before hydrothermal synthesis, while the exchanging of metal ions in ethanolic solutions with the template cations contained in the uncalcined MCM-41 was performed in the TIE method. XRD and N2-adsorption measurements showed that the mesoporous regularity was not destroyed with both synthetic methods for all the metal ion-containing MCM-41 with appropriate contents of metal cations.For V-MCM-41, the characterizations with mainly EXAFS suggested that V5+ cations were in tetrahedral coordination and mainly incorporated inside the framework of MCM-41 to substitute Si4+in the samples by the DHT method. Tetrahedrally coordinated Vanadyl species were also obtained by the TIE method, but the VO4 was dispersed on the wall surface of MCM-41. The V-MCM-41-DHT showed higher selectivity in the partial oxidations of C3H8 and i-C4H10 to alkenes and acrolein and methacrolein, but the V-MCM-41-TIE exhibited better catalytic activities in the partial oxidation of CH4 to HCHO and the oxidative dehydrogenation of C2H6.For Fe-MCM-41, EXAFS studies indicated that the DHT method also resulted in Fe3+ cations incorporated inside the framework of MCM-41 if iron content was lower than ca. 1 wt%. However,aggregated iron oxides with iron in octahedral coordination were mainly observed in the calcined Fe-MCM-41 by the TIE method. In the partial oxidation of CH4 to HCHO with O2 and the epoxidation of styrene with H2O2, the Fe-MCM-41 by the DHT method exhibits remarkably higher catalytic performances than that by the TIE method.Chromium could not be incorporated inside the framework of MCM-41 to substitute Si4+, and both synthetic methods led to surface chromate species. However, the DHT method resulted in only monochromate species on the wall surface of MCM-41 while polychromate species existed over the sample by the TIE method as indicated by the UV-Raman spectroscopic studies. The two types of Cr-MCM-41 exhibited distinctly different catalytic behaviors in the partial oxidation of CH4 with O2.The Cr-MCM-41-DHT was remarkably more selective towards HCHO formation.     

分子氧/醛/过渡金属盐体系选择性氧化二苯硫醚的研究(英文)

在温和的反应条件和三氧化二铁或三氧化二钴存在下 ,结合使用分子氧和正戊醛以及采用“一步法”的方式 ,可有效和选择性地发生二苯硫醚氧化成相应的亚砜或砜的反应。与传统的氧化剂相比 ,此方法更安全和简便。     

Theoretical Study of Electron Density Delocalization in the Excited States of Transition Metal Complexes

This paper presents a theoretical study of electron density delocalization effects over an electron-accepting ligand in metal-to-ligand charge-transfer (MLCT) complexes in the excited states, where the ligand is 4,4'-X₂-2,2'-bpy (X = H, NH₂, CH₃, Ph, Cl, CO₂Et, NO₂, bpy = 2,2'-bipyridine) or terpy (2,2':6',2'-terpyridine). Optimal geometry calculations are performed for neutral ligand molecules and their radical anions modeling the state of the ligands during MLCT excitations. Spin density distribution over atoms in the radical anions is used as a measure of the degree of delocalization. The role of spin density distribution in excitation-induced changes of geometrical parameters of the ligands is considered.     

Complex Formation Between Hydroxy Naphthol Blue and First Row Transition Metal Cyanide Complexes

Abstract

It has been found that cyanide complexes of first row transition metal elements exhibit enhanced binding to hydroxy naphthol blue (HNB) relative to the binding of corresponding aquo-ions. HNB forms a 2:1 complex with Fe³⁺ and Cu²⁺ cyanides, and 1:1 complexes with all other transition metal cyanide complexes studied; formation constants have been calculated from the spectrophotometric data in each case. It is possible to use HNB as a spectrophotometric reagent for transition metal cyanide complexes, lower limits of detection being determined for each complex.     

手性金属配合物催化的前手性羰基化合物的不对称硅氢化反应研究进展

评述了近年来手性金属配合物催化的前手性羰基化合物的不对称硅氢化反应研究进展。     

Synthesis,Structural, and Antibacterial Studies of Some Transition Metal Complexes Derived from Thiosemicarbazone and Semicarbazone

A series of metal complexes of Pd(II), Pt(II), Rh(III), Ir(III), and Ru(III) with thiosemicarbazone and semicarbazone of 2-acetyl thiophene have been synthesized. Their structures were determined on the basis of elemental analyses; molar conductance; magnetic susceptibility measurements; and IR, ¹ H NMR, and electronic spectral studies. On the basis of molar conductance, the complexes may be formulated as [M(L)₂]Cl₂ and [M′(L)₂Cl₂]Cl [where M = Pd(II), Pt(II) and M′ = Rh(III), Ir(III), and Ru(III)] due to their 1:2 and 1:1 electrolytic nature. On the basis of IR, ¹ West, D. X., Liberta, A. E., Padhye, S. B., Chikate, R. C., Sonawane, P. B. V., Kumbhar, A. S. and Yerande, R. G. 1993. Coord. Chem. Rev., 123: 49[Crossref], [Web of Science ®] , [Google Scholar]H NMR, and electronic spectral studies, an octahedral geometry has been assigned for Rh(III), Ir(III), and Ru(III), while square planar geometry has been assigned for the Pd(II) and Pt(II) complexes. The synthesized ligands and their complexes have been screened for bactericidal activity against several bacterial species (i.e., B. macerans, A. aureus, E. coli), and it is shown that the metal complexes act as more active antimicrobial agents than the uncomplexed ligands from which they derive.     

过渡金属配合物在不对称合成中的催化应用

综述了过渡金属配合物在不对称氢化、不对称环丙烷化、不对称环氧化等不对称合成中的催化应用以及最新的进展。参考文献35篇。