聚合负载三氯化钕配合物的合成及其催化活性——含硫醇和亚砜基团的配合物

合成了含—CH     

氯化钕配合物在4—乙烯吡啶聚合反应中的催化作用

氯化钕配合物是双烯烃聚合催化剂组分之一 ,与烷基铝所构成的二元体系对丁二烯聚合具有较佳活性 [1,2 ] ,但用氯化钕配合物催化极性单体的聚合反应尚未见报导 .极性单体的聚合是人们感兴趣的课题 ,例如 Benito等 [3 ]用过渡金属化合物 (VCl3-Al Et3)体系催化聚合 4-乙烯吡啶 (4VPy)极性单体 .但是它的催化活性较低 ,催化效率为 3.1×1 0 -4 kg· mol-1· h-1.我们研究了将含少量的氯化钕配合物催化剂用于该聚合反应 ,催化活性得到很大提高 ,催化效率达到 50 .71 Kg· mol-1· h-1.表明氯化钕配合物催化体系不仅对双烯烃而且对极性单体聚…     

聚合物载体-稀土金属配合物的研究ⅩⅦ聚(苯乙烯-4-乙烯基吡啶)钕配合物在丁二烯聚合中的催化行为

聚合物载体－稀土金属配合物的研究．聚（苯乙烯－４－乙烯基吡啶）钕配合物在丁二烯聚合中的催化行为李晓莉于广谦＊李玉良（中国科学院长春应用化学研究所长春１３００２２）关键词苯乙烯，乙烯基吡啶，共聚物，钕配合物，丁二烯聚合１９９６－０４－１１收稿，１９９６...     

丙酰胺氯化稀土配合物及其氯化钕配合物催化丁二烯聚合的活性

合成了组成为ＬｎＣｌ３·３ＰＡ的丙酰胺氯化稀土配合物（Ｌｎ＝Ｐｒ，Ｎｄ，Ｅｕ，Ｄｙ；ＰＡ＝Ｃ２Ｈ５ＣＯＮＨ２）．ＩＲ表明，丙酰胺是通过酰胺基团的Ｏ与Ｎｄ进行配位．ＮｄＣｌ３·３ＰＡ配合物与烷基铝组成的二元体系，无论是三异丁基铝，二异丁基氢铝或者是三乙基铝都对丁二烯聚合具有较高的催化活性，而且所得聚丁二烯的顺式－１，４结构含量都在９８％以上．     

Characterization of Polymer-Supported Rare-Earth Metal Complexes and Their Catalytic Behavior in Polymerization of Conjugated Dienes

The polymerization and catalytic behavior of catalyst systems composed of polymer-supported rare-earth metals were investigated. The catalyst systems show high catalytic activity and stereospecificity for butadiene polymerization. The catalytic efficiency for SMC (styrene-2-(methylsul-finyl)ethyl methacrylate copolymer).NdCl_3-Al(i-C₄H₉)₃ system is twice or three times that of the NdCl₃.4DMSO system. The activity of the ternary system SAAC (styrene-acrylic acid copolymer).Nd-Ph₃CCl-Al(i-C₄H₉)₃ was up to 170 kg polybutadiene/(g Nd-h). The cis-1,4 content of polybutadiene was more than 98%. This system was also used for isoprene polymerization. The cis-1,4 content of the polyisoprene obtained was about 96%     

Effect of Organoaluminum Compound on Kinetic Nonuniformity and Structure of Active Centers of Neodymium Catalytic Systems in Butadiene Polymerization

The effect of organoaluminum compound nature on the kinetic nonuniformity of the active centers of neodymium-containing catalytic systems at butadiene polymerization was studied. The concentrations of each type of active centers were calculated.     

Pretreatment of Polymer-Supported Pd-Co and Its Catalytic Activity

l/or if llctcrogclleous catalyst, it is c('lllllloll that dillbrcnt 1llcthods of preparation result ina dillbrcllcc ill tile catalytic activity, altllotlgll its composition is the same. For atriltlitiotlill if')lllogctlcolls catalyst witll ljxc(l c(f)lllpositioll, its catalytic activity usuallydt)es hot cllallgc Witll tile llletllod elf l,l'cl,arutioll. I'olylller-supported catalysts are calledtile lletcrogcllizc(1 llolllogcllcolls catalysts that colllbille the nlcrits of h()1llogcncous andllc…     

吡啶-三唑金属配合物的合成及其在乙烯聚合反应中的催化性能

以苄氯、吡啶炔和叠氮化钠为原料,在铜(Ⅰ)催化下,通过Click反应制得新型配体1-苄基-4-邻吡啶基-1,2,3-三唑(1); 1分别与无水FeCl₂, CoCl₂或NiBr₂ ·DME反应合成了3个新型的吡啶基三唑金属配合物(2~4),其结构经¹H NMR, ¹³C NMR, IR和元素分析表征。考察了2~4对乙烯聚合反应的催化性能。结果表明：以甲基铝氧烷(MAO)为助催化剂, 4具有最高的催化活性,在温度为20 ℃, Al/Ni为2 500条件下,催化活性达8.8×10⁵ g·mol^-1·h^-1。     

Heterogeneous Ziegler‐Natta Catalyst Based on Neodymium for the Stereospecific Polymerization of Butadiene

The synthesis of a series of neodymium complexes supported on modified silica is reported. In an initial step the silanol groups were masked by a Lewis acid (BCl₃, AlCl₃, TiCl₄, ZrCl₄, SnCl₄, SbCl₅, HfCl₄), and then a soluble arene complex Nd(η⁶‐C₆H₅Me)(AlCl₄)₃ formed in situ was reacted with the modified silica. The supported complexes are active and highly stereospecific for butadiene polymerization; 1,4‐cis insertion is superior by 99%. The catalyst based on a treatment of silica with BCl₃ is the most efficient.     

Quantum-Chemical Calculations of the Structure of the Triplet Reaction Complexes in Anionic Polymerization of Butadiene

A new mechanism of anionic polymerization of butadiene, radically changing the existing concepts on the structure and properties of the reaction complex, is suggested. It is stated that an elementary chemical process involves excitation into the low-lying triplet state of the living polymer–monomer complex, characterized as a transfer of a charge (electron) and cation (Li⁺ or Na⁺) from the terminal unit to the monomer molecule. In the framework of this concept, the probability of chemical bonding is determined by the spin density on the radical centers of reagent molecules. The semiempirical and ab initio 6-31G** calculations have revealed a strong interaction in the ground electronic state of the complex (5-10 kcal/mole) and low energies of the excited triplet levels (< 10 kcal/mole). A mechanism of cis-trans-isomerization in the terminal unit of the living polymer is suggested. The mechanism involves concerted rotation around the C - C bond and migration of Li between the _C and C atoms. The new approach is shown to be fruitful for microstructure analysis of polybutadiene in relation to the type of cation and the state of the terminal unit of the living polymer.     

氯化稀土乙二醇二甲醚配合物催化丁二烯聚合

以Nd2O3、(CH3)3SiCl和乙二醇二甲醚(DME)为原料,合成了NdCl3·2DME配合物,并将其用于催化丁二烯聚合。 考察了助催化剂种类与用量、陈化温度和聚合时间对聚合的影响。 结果表明,以烷基铝与MAO共同作为助催[JP2]化剂时具有高聚合活性,而单独以烷基铝或甲基铝氧烷(MAO)为助催化剂时聚合活性很低。 当n(Nd)∶n(AlR3)∶n(MAO)=1∶30∶45时,催化活性最高。 陈化温度对聚合活性、聚合物结构及相对分子质量均有较大的影响。 陈化温度过低或者过高,聚合活性、聚丁二烯cis-1,4含量和相对分子质量均降低;陈化温度为50 ℃时,具有最高聚合活性和最高cis-1,4含量。 NdCl3·2DME催化体系所得聚丁二烯的cis-1,4含量高达98.7%（IR）,而1,4-结构总含量高达99.6%（1H NMR）。     

吡咯亚胺配体与过渡金属的反应性及其催化烯烃聚合

在经典的Brookhart吡啶双亚胺后过渡金属烯烃聚合催化剂基础上,用吡咯五元环代替吡啶六元环骨架可得到具有不同电子效应的新型吡咯亚胺配体.通过吡咯环特殊的电子效应和位阻效应可设计出种类繁多的有别于吡啶亚胺配体的配合物.综述了吡咯亚胺配体与前过渡金属(Ti,Zr等)、后过渡金属(Fe,Co,Ni,Pd等)、稀土金属(Y...     

茂型稀土金属有机配合物催化甲基丙烯酸酯类聚合研究进展

综述了茂型稀土金属有机配合物催化甲基丙烯酸酯类聚合的研究现状和最新进展。系统地介绍了不同的茂型稀土金属有机催化体系中温度、反应时间、溶剂等条件对催化甲基丙烯酸酯类聚合的影响规律,并研究其催化反应机理,最后展望茂型稀土金属有机化学今后的研究方向及前景。     

聚合物固载化聚乙二醇季胺盐型相转移催化剂的结构与催化活性

The gelatinous and macroporous phase transfer catalysts with multiple active centers were synthesized by means of quarterisation of PEG tertiary amine and chloromethylated St DVB copolymer. They were examined as phase transfer catalysts in the reaction of n C 8H 17 Br with solid NaI. The experimental results showed that the reaction rate was first order with respect to the concentration of n C 8H 17 Br. The effects of catalyst structure on the catalytic activity were also investigated. The observed reaction rate constant ( k obsd ) increased as the degree of cross linking of polymer decreased. Macroporous catalysts showed a higher activity (2～2 5 times) than that of microporous catalysts with the same degree of cross linking of polymer, particle size and amount of supported PEG. Molecular weight of PEG also showed much influence on k obsd . As molecular weight of PEG rose properly, the catalysts showed a higher activity. The results were discussed from the aspect of triphase catalysis reaction mechanism.     

茂基二苯胺基镱配合物催化甲基丙烯酸甲酯聚合

茂基二苯胺基镱配合物催化甲基丙烯酸甲酯聚合     

FeCl3-Al(i-Bu)3-phen胶体催化剂制备方法对催化丁二烯聚合性能的影响

研究了FeCl2-Al(i-Bu)3-phen胶体催化剂各组分的配比、加入顺序、陈化等制备因素对催化性能的影响。由于各组分之间形成活性位的反应是快速反应，只有按phen FeCl3 Al(i-Bu)3的加入顺序，才能有效阻止深度还原；陈化能提高稳定和较稳定的胶体催化体系的催化活性，而对于不稳定体系，采用“单加”较适宜。陈化时加少量丁二烯，其催化活性高于不加丁二烯的，这是由于生成的丁二烯聚合物可起空间稳定作用，阻碍胶粒聚结，使其稳定在小颗粒范围内；采用适宜的[phen]：[Fe]:[Al]比，可制备出小而均匀的催化剂颗粒，且有利于还原生成活性位所需的Fe^2 ,同时得到相对稳定的胶体催化体系。     

聚苯乙烯负载单茂然／RMgBr催化苯乙烯聚合的研究

合成了聚苯乙希负载的单茂钛催化剂,并与格氏试剂（RMgBr）组成催化体系。考察了聚合温度、催化体系的组成、单体浓度、 Mg/Ti摩尔比、聚合时间等条件对苯乙烯聚合的影响。结果表明,采用负载单茂钛催化剂与助催化剂格氏试剂反应,可以制备出具有较高催化活性的催化剂。DSC表明,不溶于沸丁酮的聚苯乙烯具有一定的定向性。聚合物^13G-NMR测试表明,该催化体系的聚合机理可能是：苯乙烯插入M－C键,以一级插入反应进行链增长,最后以β－H及β－苯基消除反应致链终止。     

Chelating Ruthenium Phenolate Complexes: Synthesis,General Catalytic Activity,and Applications in Olefin Metathesis Polymerization

Cyclic Ru‐phenolates were synthesized, and these compounds were used as olefin metathesis catalysts. Investigation of their catalytic activity pointed out that, after activation with chemical agents, these catalysts promote ring‐closing metathesis (RCM), enyne and cross‐metathesis (CM) reactions, including butenolysis, with good results. Importantly, these latent catalysts are soluble in neat dicyclopentadiene (DCPD) and show good applicability in ring‐opening metathesis polymeriyation (ROMP) of this monomer.