共查询到18条相似文献,搜索用时 62 毫秒
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本文研究了十二种不同取代基的芳香族腈在Lewis酸-金属体系催化下的聚合反应。结果表明, 取代基的吸电子能力越强, 聚合反应速率越快。其速率常数与Hammett方程中的取代基特性常数σ值呈线性关系, 此外, 对聚合物的结构也进行了测定。 相似文献
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本文研究了十二种不同取代基的芳香族腈在Lewis酸-金属体系催化下的聚合反应。结果表明,取代基的吸电子能力越强,聚合反应速率越快。其速率常数与Hammett方程中的取代基特性常数σ值呈线性关系。此外,对聚合物的结构也进行了测定。 相似文献
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氰基邻苯二胺1与对-溴苯基乙二醛2反应,可得到喹啉衍生物3和4,由此可进一步制得含喹啉环的二腈5和6.3和4以及6均互为异构体.合成化合物5后,进一步确定了3,4和6的结构. 相似文献
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<正> 我们曾研究了4,4'-联苯二甲腈(I)在联苯二甲腈氯化锌配合物催化下的聚合反应动力学,结果表明,该聚合反应是二级反应,聚合反应速度与氰基和配合物的浓度各成一次方比例,可用下式表示: 相似文献
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聚合色素的研究:Ⅸ.侧链悬挂偶氮型染料的聚合膦腈酸多氟烷基 … 总被引:2,自引:0,他引:2
首次将偶氮染料和聚合膦腈酸多氟烷基取代酯相结合,合成了一类具有阻燃、疏水憎油等特殊的功能聚合物。研究了合成色素的润湿性和热性能,结果表明:所合成的色素具有期望的应用特性。此外,对合成反应的机理和聚合色素的红外光谱特性也进行了初步的讨论。 相似文献
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锗桥连茚及取代茚配体相继与丁基锂及ZrCl4作用,生成锗桥连茚基及取代茚基锆化合物Me2Ge(2-R^1-4-R^2-Ind)2ZrCl2[R^1=R^2=H(1);R^1=Me,R^2=H(2);R^1=Me,R^2=Ph(3)]。化合物1-3均为内消旋和外消旋异异构体的混合物,通过多次重结晶得到化合物1和2的纯外消旋异构体及化合物3的内消旋异构体。由元素分析和^1H NMR谱表征了化合物的分子结构。研究了在甲基铝氧烷(MAO)的助催化下,化合物1-3对乙烯和丙烯聚合的催化性能。由锗桥连茚基化合物1-3得到的聚乙烯的分子量分布比一般茂金属催化剂略宽,内消旋和外消旋异构体的混合物(3)由于两个催化活性中心不等同而使得到的聚乙烯的分子量分布相当宽。外消旋异构体1和2催化丙烯聚合得到高等规聚丙烯。 相似文献
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Nd(OR)3-nCln-AlEt3催化体系对丁二烯的聚合 II.聚合物微观结构和催化剂诱导效应指数的关系 总被引:1,自引:0,他引:1
With a new series of binary catalyst Nd(OR)3-nCln-AlEt3 prepared in our laboratory, the effect to catalyst composition on the microstructure of polybutadiene was studied in detail. A linear relationship is found between the variation of the microstructure of the polymer obtained and the iductive effect index (I) which reprepresents the magnitude of the displacement of paired valence electrons on transition metal-halogen bond (MT-X) of the catalyst. This linear relationship also holds in dealing with the data published in the literature. 相似文献
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Nd(OR)3-nCln-AlEt3催化体系对丁二烯的聚合 I.聚合的一般规律 总被引:3,自引:0,他引:3
Homopolymerization of butadiene has been carried out with a new series of binary catalyst system Nd(OR)3-nCln-AlEt3 and the catalytic activity as well as the microstructure of the resulting polymer have been studied. The results indicate that the stereospecificity of the polybutadiene obtained with these beinary catalyst system (when n=2) is similar to that prepared with thernary system Nd(OR)3-Al2Et3Cl3-AlEt3, yet the catalytic activity of the former is somewhat higher. Hence, it is possible that the present simpler binary system is more preferable to be applied than the ternary. System in butadiene polymerization. 相似文献
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一类新型的双β-氨基醇的合成及催化硼烷对芳酮的不对称还原反应 总被引:7,自引:0,他引:7
以L-半胱氨酸盐酸盐出发,经与二卤代烷偶联,成酯和格氏反应制得三种双手性β-氨基醇,1,2-双[R-2-氨基-3-羟基-3,3-二苯基丙硫基]乙烷(4a),1,3-双[R-2-氨基-3-羟基-3,3-二苯基丙硫基]丙烷(4b),1,4-双[R-2-氨基-3-羟基-3,3-二苯基丙硫基]丁烷(4c)。将此类双手性β-氨基醇与硼烷在THF溶液中反应,in situ制备双手性恶唑硼烷催化硼烷对芳酮的不对称还原,产物苯乙醇的光学收率达72.8%、α-溴代苯乙醇的光学收率达91.4%。 相似文献
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利用在水溶液中的电化学聚合制备了聚吡咯烷、薄膜修饰电极. 讨论了对电化聚合的影响因素及薄膜修饰电极在不同电解质中的伏安特性, 从X-射线光电子能谱推测, 在吡咯的电化聚合过程中氧的参加引起在聚吡咯烷膜的结构中有羰基和羟基的生成. 相似文献
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《Polyhedron》1987,6(6):1295-1307
The preparation of the ortho-substituted aryldifluorophosphines 2-MeOC6H4PF2 and 2-Me2NC6H4PF2 by chlorine-fluorine exchange from the corresponding dichlorophosphines using sodium fluoride in acetonitrile in the presence of a crown ether is described. The ortho-substituted aryldichlorophosphines 2-MeOC6H4PCl2 and 2-Me2NC6H4PCl2 were prepared from the respective bis(N,N-dimethylamino) phosphines by cleavage of the PN bonds with hydrogen chloride. The reaction of 4-fluoroanisole and 2-methoxy-phenyllithium with phosphorus trichloride did not yield the expected chlorophosphines, i.e. 2-MeO-5-F-C6H3PCl2 and 2-MeOC6H4PCl2, but led to formation of 4-fluorophenyldichlorophosphite in the former, and to tris(2-methoxyphenyl)phosphine in the latter case. The difluorophosphine 2-MeOC6H4PF2 was found to undergo a spontaneous oxidation-reduction reaction with formation of the tetrafluorophosphorane 2-MeOC6H4PF4, and the cyclotetraphosphine (2-MeOC6H4P)4. A single-crystal X-ray structure determination of the latter indicated the presence of a strongly puckered four-membered ring with PP bond lengths ranging between 222 and 223 pm, and endocyclic bond angles of 84°. Vicinal MeOC6H4 groups were found arranged trans to each other. Dichloroplatinum(II) complexes were prepared, involving the two new fluorophosphines, 2-XC6H4PF2 (X = MeO or Me2N), as ligands. In neither case was any evidence found for coordination between platinum and oxygen or nitrogen, and the fluorophosphines were found to function solely as phosphorus donors. The absence of interaction between platinum and the oxygen atom in the ortho position of the ligand 2-MeOC6H4PF2 was confirmed in a single-crystal X-ray determination of the complex Cl2(2-MeOC6H4PF2)2Pt. The compound was found to exist as a planar, cis-coordinated species with PtCl bond lengths between 232 and 234 pm, and a PtP bond length of 218 pm. All compounds were characterized by NMR spectroscopy (1H, 31P and 19F, where applicable). 相似文献