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1.
锌/钴双金属氰化络合物催化环氧丙烷聚合机理   总被引:2,自引:0,他引:2  
用以二乙二醇二乙醚为有机配体的锌/钴双金属氰化络合物进行了环氧丙烷的聚合,并用扩展X射线精细结构分析方法研究了催化剂激活和环氧丙烷聚合过程中锌离子和钴离子的区域结构变化。结果表明,锌/钴双金属氰化络合物催化环氧丙烷的聚合是一个活性聚合体系。在环氧丙烷聚合过程中锌离子由与3.0个氧原子配位转变为与5.7个氧原子配位,表明聚合活性中心为5.0个氧原子配位的螯合锌离子。  相似文献   

2.
非茂金属络合物是近些年发展起来的高性能烯烃聚合催化剂,由非茂化合物作为配体与金属前体配位络合生成,以其极高的活性、聚合物分子结构的可控性、多重活性聚合等特性受到关注。综述了非茂金属络合物的研究进展,按照配体骨架和金属中心分类,阐述了非茂金属络合物催化烯烃聚合特性,为其深入研究及工业化应用提供参考。  相似文献   

3.
N,N-二甲基苯铵四(五氟苯基)硼酸盐作为含氟阳离子试剂,制备简单,应用广泛,既可以直接用作聚合催化,又可以方便地合成各类聚合催化剂,有着优异的催化性能。  相似文献   

4.
针对目前常压相转移催化法合成N,N-二乙基苯胺工艺中催化剂无法实现分离的问题,开展了非均相固体相转移催化剂催化合成N,N-二乙基苯胺工艺研究。以苯胺、溴乙烷为原料,氢氧化钠作为缚酸剂,在磷钼钒杂多酸季铵盐催化剂催化合成了N,N-二乙基苯胺,实现了固体非均相相转移催化剂的工艺路线,及催化剂的快速分离。利用单因素试验法对N,N-二乙基苯胺合成工艺进行了优化,得到最佳工艺条件为:反应温度为54℃,n(苯胺)∶n(溴乙烷)=1∶2.4,催化剂用量分别为1.6g,反应时间为5.5h,氢氧化钠用量为0.55 mol,氢氧化钠浓度为35%,收率达到82.8%。  相似文献   

5.
以N,N-二甲基月桂酰胺和氢气为原料,在Ni/γ-Al2O3催化剂作用下,采用高压釜进行催化加氢反应合成N,N-二甲基月桂胺。研究了温度、压力、催化剂用量和二甲胺的通入等对N,N-二甲基月桂酰胺转化率,N,N-二甲基月桂胺选择性及产率的影响。结果表明,在220℃,2.0 MPa,催化剂用量为N,N-二甲基月桂酰胺质量的2.5%,通入二甲胺,反应7 h的条件下,N,N-二甲基月桂酰胺转化率,N,N-二甲基月桂胺选择性及产率分别为97.9%,99.5%和97.4%,二甲胺的通入抑制了副反应的发生,提高了目标产物N,N-二甲基月桂胺的产率。  相似文献   

6.
综述了用于乙烯水相配位聚合反应的有机铑络合物、中性Ni(II)阴离子P-0配体络合物、中性Ni(Ⅱ)水杨醛亚胺配体络合物和阳离子α-二亚胺配体络合物的合成及所得的聚合物的特性以及Ni络合物催化的乙烯水相乳液聚合反应。水作为反应介质具有很好的应用前景。水相聚合反应催化剂的研究今后将会成为聚烯烃催化剂研究的一个重要组成部分。  相似文献   

7.
根据锌、镁及钙金属络合物不同配体的结构特点,综述了近年来锌、镁及钙金属络合物用于催化丙交酯开环聚合的研究进展,以及影响催化剂活性和立体选择性的主要因素。锌、镁及钙金属络合物具有生物相容性,作为催化剂使用时,对环境友好,且在催化丙交酯开环聚合中表现出很高的活性以及很好的立体可控选择性,但该类催化剂对空气及水敏感,需要无水无氧条件下才能催化丙交酯聚合,影响了其应用。因此,研究催化剂的结构特点、开发活性高且对空气敏感程度低的催化剂十分必要。  相似文献   

8.
异羟肟酸过渡金属络合物在乙苯氧化中的催化性能研究   总被引:6,自引:0,他引:6  
研究了 N-苯甲酰 -N-苯基羟胺 ( BPHA)类过渡金属络合物在乙苯均相氧化中的催化行为 ,考察了络合物催化剂中心金属离子、配体结构以及添加助剂对络合物催化性能的影响 ,并找到了催化剂、助剂的最佳使用浓度及氧化反应的最适宜温度。结果表明 ,中心金属离子的电子结构对络合物催化性能影响最大 ,其活性顺序为 :Cu( BPHA) 2 >Co( BPHA) 2 >Fe( BPHA) 2>Mn( BPHA) 2 >Ni( BPHA) 2 ,配体结构对催化性能有一定影响 ,配体的芳环上有吸电子基团时 ,催化剂分解氢过氧化物的能力增加 ,主要分解产物为苯乙酮。添加轴配体对氧化反应及催化剂的选择性有较大影响 ,其中含端羟基的非环冠醚类及大环冠醚对氢过氧化物的生成和分解都有加速作用 ,含氮助剂吡啶对氧化反应有抑制作用  相似文献   

9.
采用以配体为中心的催化剂设计理念,设计并合成了一种新型Ti系FI催化剂双[N-(3-叔丁基水杨醛)-2,6-二氟苯胺-4-苯乙烯基苯胺]二氯化钛(IV)(2F-BSFI)。采用核磁氢谱(1H-NMR)、核磁碳谱(13C-NMR)和傅里叶红外(FTIR)对催化剂配体N-(3-叔丁基水杨醛)-2,6-二氟苯胺-4-苯乙烯基苯胺(2F-BS)进行了表征。用1H-NMR、13C-NMR、元素分析(EA)和电喷雾电离质谱(ESI-MS)表征了催化剂结构。以2F-BSFI和助催化剂甲基铝氧烷(2F-BSFI/d-MAO)为催化体系催化乙烯聚合,考察了聚合时间、温度、助催化剂用量对催化性能的影响。结果表明,随着聚合时间的增加,产物分子量分布指数(PDI)稳定在较低水平,产物数均分子量Mn几乎呈线性增长,说明该催化剂催化乙烯聚合具有拟活性聚合特征。  相似文献   

10.
中国专利     
[N^O]型双齿配体与锆金属配位的烯烃聚合催化剂及其制备方法本发明为一种[N^O]型双齿配体与锆金属配位的烯烃聚合催化剂及其制备方法。该催化剂表达式为ZrL_2Cl_2,其中L表示一种含有可与金属配位的N,O原子的配体。该催化剂不仅具有独特新颖的结构,催化乙烯聚合具有较高的催化活性,并且催化剂制备简单。该催化剂作为A,B组分配合,可用于催化乙烯聚合,制备高相对分子质量聚乙烯产品。公开号CN 101824109公开日2010年9月8日申请人复旦大学  相似文献   

11.
The cobalt(II), nickel(II) and copper(II) complexes of N-Isonicotinoyl-3-methyl-4-(p-hydroxybenzilidene)-2-pyrazolin-5-one (IMHBP) with different counter anions have been prepared and characterized. An octahedral geometry has been assigned to the cobalt(II) and nickel(II) complexes and a square-planar structure to the copper(II) complexes. IMHBP acts as a neutral bidentate ligand in all these complexes by coordinating through the oxygen atoms of the amide group and carbonyl at position-5. The other coordination sites are satisfied by anions alone or anions and water molecules. The ligand and the complexes were screened for their possible antitumour activity. The copper(II) complexes are appreciably active in reducing mice tumours.  相似文献   

12.
A series of different steric hindrance nickel(II) complexes 1 – 6 bearing 2,6‐bis(imino)pyridine ligands have been synthesized and characterized. The molecular structures of the complexes 3 – 5 were determined by X‐ray diffraction analysis. The coordination geometry around the nickel center of the complexes is either square pyramid for complexes 3 and 4 or trigonal bipyramid for complex 5 . All of the nickel complexes exhibit high catalytic activity for norbornene polymerization in the presence of MAO, although low activity for ethylene oligomerization and polymerization. The effects of the Al/Ni ratio, halogen, monomer concentration, temperature, and reaction time on activity of catalyst for norbornene polymerization and polymer microstructure were investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

13.
NiII, CoII and FeII complexes of 2-(2-pyridyl)quinoxaline were synthesized and used in the ethylene oligomerization with methyl-aluminoxane (MAO) as cocatalyst. The nickel complex system mainly produced α-olefins with good activity, while the cobalt and iron complexes showed only marginal activity.  相似文献   

14.
In this review, an attempt is made to systemise the rôle which bidentate phosphinamine (P,N) ligands play in asymmetric catalysis. The ligands will be classified, not by the reaction to which their metal complexes have been applied, but by the nature of their donor atoms. In this manner the development of ligand architectural design can be more easily monitored. The asymmetric transformations to which metal complexes of these ligands have been applied include among others, palladium‐catalysed allylic substitutions, copper‐catalysed 1,4‐additions to enones and rhodium‐catalysed hydroboration of vinylarenes. Excellent enantioselectivities, regioselectivities and reactivities have been achieved in each of these processes.  相似文献   

15.
A series of Ni(II)-based bidentate -diimine complexes bearing two alkyl (alkyl = methyl, ethyl and isopropyl) substituents on each imine aryl group were studied as precatalysts for the polymerization of ethylene. These new catalysts were observed to show high activity in combination with methyl aluminoxane (MAO) and produced high molecular weight polyethylenes. The effects of the steric bulk of ortho-aryl substituents of the ligand on the catalytic activity and the resulting polyethylene microstructure were investigated. Kinetics of polymerization was also studied by changing important parameters such as temperature and MAO concentration. The polymerization activity, polymer molecular weight and resulting polymer microstructure were drastically changed according to the catalyst structure modification and polymerization parameters.  相似文献   

16.
由乙二胺和对甲苯磺酰氯反应制得N,N′-双(对甲苯磺酰基)乙二胺。此步最佳工艺条件为:n(对甲苯磺酰氯)∶n(乙二胺)=2.2∶1,反应溶剂为苯,反应温度为40~45℃,反应时间为6h,收率80%。由丙烯酸甲酯和溴反应制得α,β-二溴丙酸甲酯,收率为88%。再由上述二种中间体反应合成标题化合物,此步省略了N,N′-双(对甲苯磺酰基)乙二胺的二钠盐制备,收率为73%。  相似文献   

17.
Stereochemistry of N,N′-Bis-[3-(o-ethoxyphenoxy)-2-hydroxy-propyl]-ethylendiamine N,N′-Bis-[3-(o-ethoxyphenoxy)-2-hydroxy-propyl]-ethylene diamine ( 5 ), synthesized from racemic 1,2-anhydro-3-O-(o-ethoxyphenyl)-glycerol ( 1 ) and ethylene diamine ( 2 ) or N,N′-dibenzyl ethylene diamine ( 3 ) crystallized in two fractions with different melting points. Both of these analytically pure products gave identical two spot tl-chromatograms on achiral phases. Attempts were made to resolve the mixtures which proved to consist of configurative but not constitutive isomers. Optically pure products were synthesized from chiral precursors.  相似文献   

18.
Simple synthetic procedures, reactions of Re(CO)5Cl with potentially tridentate N∩N∩OH ligands (Schiff bases prepared from aliphatic or aromatic amines and salicylic aldehyde) lead to formation of monomeric complexes of fac-Re(CO)3+ ion. Three obtained complexes have been characterized by means of elemental analyses and IR, UV–vis, and EI-MS techniques. Molecular structures of the synthesized species were investigated using X-ray diffraction measurements. Depending on the nature of N∩N∩OH ligand the investigated Schiff bases form with fac-Re(CO)3+ ion bidentate or tridentate chelates with N∩N, N∩O or N∩N∩O coordination types.  相似文献   

19.
Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC) with 2-methoxybenzaldehyde (2MB) and 3-methoxybenzaldehyde (3MB). The ligands were reacted separately with acetates of Cu(II), Ni(II) and Zn(II) yielding 1:2 (metal:ligand) complexes. The metal complexes formed were expected to have a general formula of [M(NS)2] where M = Cu2+, Ni2+, and Zn2+. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1) and S2M3MBH (2) were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7) and estrogen receptor-negative (MDA-MB-231) breast cancer cell lines. Only the Cu(II) complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II) complexes have a strong DNA binding affinity.  相似文献   

20.
曾凯  韦鹏  刘峙嵘 《煤炭转化》2006,29(4):60-63,68
在不同pH下泥煤多次吸附镍,用傅立叶变换红外光谱(FTIR)研究了泥煤与镍元素作用前后的光谱特征.结果表明,pH对泥煤的影响较大;泥煤的红外光谱与腐植酸相似;泥煤与镍元素结合后的红外光谱中归属于1711cm^-1的羧酸二聚体吸收峰减小甚至消失,同时归属于COO^-的1610cm^-1和1410cm^-1处的振动吸收增强,说明泥煤中的羧基与镍离子发生了配合作用,旦大部分是双齿结构.  相似文献   

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