共查询到20条相似文献,搜索用时 78 毫秒
1.
含二联苯结构聚醚醚酮的微结构及磺化改性的性质研究 总被引:1,自引:1,他引:0
本文利用PEEK的AM1条件优化结果,并结合二联苯结构与不含二联苯结构聚醚醚酮的结构相似性,确定了含二联苯结构聚醚醚酮重复单元的最优构型,据此给出了此分子链的微观构型。在实验上也研究了磺化改性对此聚合物红外光谱的影响。 相似文献
2.
3.
聚合物电解质中离子输运机制的谱学研究 总被引:3,自引:0,他引:3
聚合物电解质是新一代锂离子电池所需要的重要材料,本文从分析聚丙烯腈增塑剂-LiClO4体系中各组份间的相互作用出发,用Raman光谱,红外光谱,X射线光电子能谱及核磁共振等谱学方法研究了聚合物电解质中各组份之间的相互关系和Li^+离子在聚合物电解质中的输运机理。 相似文献
4.
5.
聚合物玻璃化转变的本质一直是困扰材料科学工作者的一个难题,也吸引了众多学者利用各种测试手段对其进行研究。由于对聚合物的结构较为敏感,傅里叶变换红外光谱(FTIR)被广泛应用于研究聚合物在玻璃化转变期间的构象变化。对此有相当数量的研究报道,本文对这些研究工作进行了介绍。目前用FTIR对玻璃化转变的研究工作大多集中于转变过... 相似文献
6.
新型三维配位聚合物[Fe(C_5H_4NCOO)_2]_n的可控合成、晶体结构和UV-VIS-NIR反射光谱研究 总被引:7,自引:0,他引:7
近年来,金属有机配位聚合物由于其独特的电学、磁学、催化和光学性能而受 到普遍关注。通过选择不同的多齿配体和金属离子,可以组装成具有各处新型骨架 结构和特殊物理化学性能的配位聚合物。异烟酸根可以通过吡啶环氮原子和羧基氧 原子与金属离子配位,生成配位聚合物。本文采用三氯化铁和4-氰基吡啶在水热条 件下的反应可控地合成具有三维骨架结构的配位聚合物[Fe(C_5H_4NCOO)_2]_n,并 进行元素分析、红外光谱表征,单晶结构测定和UV-VIS-NIR(紫外-可见-近红外) 反射光谱研究。 相似文献
7.
ATR-FTIR光谱技术在聚合物膜研究中的应用 总被引:7,自引:0,他引:7
红外光谱是聚合物研究中常用的一种表征手段,而衰减全反射红外光谱(ATR-FTIR)更是由于在研究聚合物薄膜方面具有显著的优势而被广泛使用。逐层组装(layer-by-layer Assembly)技术是一种常用的组装聚合物超薄膜的方法,ATR-FTIR光谱技术的引入可以在获取膜组装过程中相应信息的同时有效地避免表征过程中对样品的损害。另一方面,ATR-FTIR方法与二维相关光谱技术(two-dimensional correlation spectroscopy, 2D correlation spectroscopy)相结合也是研究小分子(主要是水分子)在聚合物薄膜中的渗透行为的有效手段。本文对ATR-FTIR的基本原理和显著特点作了介绍,并以实例阐述该方法在逐层组装技术和水分子在薄膜内渗透行为研究两方面的应用。 相似文献
8.
高分子药物研究:I.5—氨基水杨酸与二元羧酸缩聚物的合成 总被引:2,自引:0,他引:2
通过5-氨基水杨酸与二元羧酸进行缩聚反应,合成了六种主链含有5-氨基水杨酸的高分子化合物,用红外光谱和元素分析确定了聚合物的结构。聚合物水解实验表明,它们在酸性,中性和碱性介质中均能水解,水解速率(r)的大小依次为rpH=13.0>rpH=7.0>rpH=2.0。 相似文献
9.
10.
11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
12.
Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
13.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
14.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%). 相似文献
15.
Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
16.
Shashikant U. Dighe Surya K. Samanta Shivalinga Kolle Sanjay Batra 《Tetrahedron》2017,73(17):2455-2467
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones. 相似文献
17.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates. 相似文献
18.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
19.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
20.
Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献