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1.
本文报道了真空状态下主体β-环糊精和客体对-甲基苯酚形成的包结物在一定时间间隔内动态微观结构的分子动力学模拟结果。研究表明,对-甲基苯酚在环糊精腔内的运动具较大的自由度,但由于存在范德华作用,其运动受到一定的限制,同时通过计算观察到包结前后主客体的某些微观结构和性质发生了较为明显的变化。本文还给出了计算得到的主客体包结物的时间平均构象。  相似文献   

2.
环糊精包结物的制备与研究方法   总被引:18,自引:0,他引:18  
环糊精是由6,7,8个葡萄糖基构成的环状化合物,分别叫做α,β,γ-CD。它们具有亲水的外围及疏水的内腔,可与多种物质形成包结物,而改变物质的特性,因而被广泛应用于各行各类,为了更好地研究环糊精包结物,在查阅大量文献的基础上,总结出环糊精包结物的多种制备方法及研究方法。  相似文献   

3.
水溶液中环糊精包结物的包结常数的测定方法   总被引:21,自引:0,他引:21  
环糊精(CD)是由6,7,8个葡萄糖基构成的环状化合物,分别叫做α、β、γ-CD,它们具有“外亲水,内疏水”的独特性质,可以与多种物质形成包结物,而改变物质的特性,因而被广泛应用于各行各业中,在以往研究的基础上,总结了多种测定环糊精包结常数的方法,以便能更好地研究并开发利用具有极大潜力的环糊精。  相似文献   

4.
研究了不同pH值3-羟基-2-萘甲酸的荧光性质,并用荧光双倒数法测定了3-羟基-2-萘甲酸与β环糊精包结物在不同pH值的生成常数,结果表明疏水作用和氢键对包结物的形成起重要作用。  相似文献   

5.
β—环糊精交联聚合物与有机显色剂客体包结反应研究   总被引:8,自引:0,他引:8  
β-环糊精与环氧氯丙烷交联共聚物是一种具有三维网状结构的聚合树脂,它保留了β-环糊精所原有的与有机疏水基团形成包结物的特性,与一系列含有芳得环的有机显色剂配体(如吡啶偶氮染料,变色酸双偶氮试剂,三苯甲烷类碱性与酸性染料以及杂氧蒽酮类试剂等)均可形成相应的包结配合物,着重研究了有关包结配合物的稳定性及影响稳定性的各种因素,为进一步研究包结物分离富集痕量金属提供必要的理论依据。  相似文献   

6.
首先合成了单取代的β环糊精ATRP引发剂(β-CD-Br),利用核磁、质谱等对其进行了表征,并通过ATRP聚合制备了端基为β-环糊精的水溶性聚合物聚甲基丙烯酸N,N-二甲基氨基乙酯(β-CD-PDMAEMA).聚合物β-CD-PDMAEMA可以通过环糊精与金刚烷之间的主客体包结络合作用与端基为金刚烷的聚芴(PFADA)形成水溶性的聚芴纳米粒子.重点探讨了β-CD-PDMAEMA与PF-ADA的质量比和不同的组装方法对纳米粒子尺寸及分布的影响,研究表明质量比为4∶1时通过向2种聚合物的THF混合溶液中缓慢加水的方法可得到流体力学半径(R_h)为80 nm、PDI为0.11的纳米粒子.最后利用透射电子显微镜和原子力显微镜对纳米粒子的形貌进行了表征,进一步依照纳米粒子的R_h随温度升高的实验可以证实纳米粒子具有明显的核壳结构,其中刚性的聚芴为核半径约为50 nm,水溶性的PDMAEMA聚合物为壳.  相似文献   

7.
化学修饰环糊精在醇/水混合溶剂中的包结行为   总被引:2,自引:0,他引:2  
环糊精 (CD)及其衍生物在主客体化学中占有重要位置[1].在环糊精母体上引入一个荧光发色团,可使CD变为在光谱上有响应的主体化合物,如引入一个丹酰基,在水溶液中由于疏水相互作用,该荧光团易于进入CD内腔形成“自包结”配合物[2 -3].我们曾合成了以氮氧杂 十一烷基链相连接的单个N,N二甲氨基查尔酮 (DMAC)修饰的 β CD衍生物 (DMAC CD),也表现出良好的自包结特征[4].前人曾有吖啶/CD配合物体系与低浓度醇分子形成三元包结物的报导[5,7],而在醇水混合溶剂中主客体配合物的稳定性研究较少.…  相似文献   

8.
β-环糊精由于其特殊的分子结构,对某些物质具有包结作用,并形成较稳定的复合物,极化能力大大增强,在色谱中具有更大的保留值,气相色谱固定相分离混合物过程中,β-环糊精包结物较β-环糊精具有更强的分离能力。分别对β-环糊精及其包结了某些物质后的β-环糊精作气相色谱固定相,对一系列低佛点有机化合物的分离和保留行为进行研究,比较了β-环糊精包结前后的不同的分离效果,并初步探讨了有关的形成机理和分离机制。  相似文献   

9.
极谱法研究大黄酸-环糊精包结物   总被引:7,自引:0,他引:7  
李向军 《电化学》1999,5(3):348-351
大黄酸是中药大黄中的有效成份,具有抗菌、止咳和抗肿瘤作用.近年来对大黄酸的研究日渐深入,其应用日趋广泛.由于其水溶性低,且对胃肠有刺激作用,导致生物利用度低,应用受到了限制.环糊精是由葡萄糖基以1,4糖甘键连成的中空筒状化合物,具有疏水的内腔和亲水的外表面,可有效地包结各种客体分子,从而能改变客体分子的状态、稳定性、溶解度等理化特性[1],文献曾经报道β_环糊精与药物形成包结物,可提高溶解度[2]及降低对胃的刺激性[3].近来用电化学方法研究环糊精的报道日渐增多[4,5].本文用极谱法研究了β_…  相似文献   

10.
以自组装方式在石英晶体谐振器(QCR)的金电极表面修饰末端含巯基的β-环糊精衍生物(β-CDd),用压电石英传感器在线监测萘系衍生物与之发生包结反应的过程,探讨了温度、浓度、取代基数目和位置对包结配合物稳定常数(Kin)的影响,从理论上并从实验证明了Kin所遵从的关系式;结果表明,所形成的包结配合物的化学计量均为1:1,包结配位反应过程符合Langmuir吸附模型;β-环糊精衍生物对客体分子大小、取代基数目和位置等都有良好的选择区分功能。  相似文献   

11.
Wang XP  Pan JH  Li WH  Zhang Y 《Talanta》2001,54(5):805-810
The interaction of cyclodextrins with meso- Tetrakis (4-N-trimethylaminobenzyl) porphyrin (TAPP) in 0.1 mol l(-1) phosphate buffer (pH 7.0, 20 degrees C) has been studied by polarography. The TAPP can form the 1:1 inclusion complex with Sulfobutylether-beta-cyclodextrin (SBE-beta-CD) and1:2 inclusion complexes with other four cyclodextrins. A new expression, which is used to calculate the inclusion constant for1:2 inclusion complex by polarography, has been educed and testified firstly in this paper. Furthermore, the inclusion abilities of different kinds of cyclodextrins are compared. The result shows the inclusion ability of anionic cyclodextrin SBE-beta-CD with cationic porphyrin TAPP is very strong. It suggests that the charge attraction between CDs and TAPP plays an important role in the inclusion procedure except for the hydrophobic effect. The inclusion formation of anionic cyclodextrins with drugs can increase released rate of drugs at high pH; therefore, the suparmolecular data for the controlled release of the drugs that owned the similar properties as hematoporphyrin have been offered by polarography in this paper.  相似文献   

12.
The cyclodextrins(CDs) are a class of cyclic oligosaccharides made up of six(a), seven(a)or more [a-(1,4)-linked] D-glucopyranose units, and shaped like truncated cones with primary and secondary hydroxyl groups crowning the narrower rim and wider rim respectively. As they have a hydrophobic cavity of appropriate dimension, they can bind with various guest moleculars, such as hydrocarbon, cyclohexane, aromatic compounds, to form inclusion complexes. The cyclodextins inclusion complexation has been considered an ideal model mimicking the enzyme-substrate interaction and a lot of effect has been devoted to it. In this paper, we report our investigation on the inclusion complexation behavior of a-cyclodextrin(a-CD) with diphenyl compounds in order to further explore the molecular recongnition mechanism of 2:1 inclusion complexation of a-CD with aromatic compounds.Figure 1: Possible structures of the inclusion compounds.The inclusion complexation behavior of a-CD with sym-diphenyl-urea, sym-diphenyl-thiourea and diphenyl kotone as respective guest moleclars was studied by ultraviolet spectrometric titrations.The absorption spectral changes observed for the compounds in the absence and presence of a-CD are used to draw the corresponding Benesi-Hildebrand plots and caculate the complex stability constant value (Ks) for the inclusion compounds.The 2:1 inclusion complexations show higher binding constants by cooperative binding of one guest molecular in the closely two hydrophobic cyclodextrin cavites as compared with 1:1 inclusion complexations.The highest value observed for sym-diphenyl-urea could be due to the formation of a hydrogen bond between the carbonyl group and the hydrogen in the hydroxyl group of CD and this is not possible with sym-tiphenyl-thiourea. The lowest value observed for diphenyl kotone indicate the hydrophobic interaction is one of the binding force of cyclodextrin inclusion complex.  相似文献   

13.
何俊 《化学通报》2012,(7):653-656
探索了超临界二氧化碳介质中甲基-β-环糊精和两种线型聚丙二醇间的穿合(threadinginclusion);并和相同温度下空气中的固态包合反应进行了比较。在无溶剂状态下,原处于无定形态的甲基-β-环糊精可与聚丙二醇链作用形成具有圆筒状结构的结晶态包合物,引入适量二氧化碳可明显增大包合反应的程度;将聚丙二醇链两端的羟基换为丙烯酸酯基可使反应进一步加强。  相似文献   

14.
Properties of inclusion complexes between morin (M) and beta-cyclodextrin (betaCD), 2-hydroxypropyl-beta-cyclodextrin (HPbetaCD) and Heptakis (2,6-O-di methyl) beta-cyclodextrin (DMbetaCD) such as aqueous solubility and the association constants of this complex have been determined. The water solubility of morin was increased by inclusion with cyclodextrins. The phase-solubility diagrams drawn from UV spectral measurements are of the A(L)-type. Also ORAC(FL) studies were done. An increase in the antioxidant reactivity is observed when morin form inclusion complex with the three cyclodextrin studied. Finally, thermodynamics studies of cyclodextrin complexes indicated that for DMbetaCD the inclusion is primarily enthalpy-driven process meanwhile betaCD and HPbetaCD are entropy-driven processes. This is corroborated by the different inclusion geometries obtained by 2D-NMR.  相似文献   

15.
采用共沉淀法制备了桂油与 β -环糊精的包合物 ,并用差热分析仪和气相色谱仪对包合物进行了分析 ,研究结果表明该方法包合桂油有利用率高、操作简便等优点 ,有利于拓宽桂油的应用面。  相似文献   

16.
In this paper, we describe a new polymerization manner termed as "vine-twining polymerization" to produce amylose-polymer inclusion complexes. The polymerization was achieved by an enzymatic polymerization of alpha-D-glucose-1-phosphate monomer catalyzed by phosphorylase in the presence of polyTHF as a guest polymer. The structure of the product was determined by X-ray powder diffraction and (1)H NMR measurements to be the inclusion complex. The formation process of the inclusion complexes during the polymerization was also evaluated. Furthermore, the formation of the inclusion complexes by this polymerization method by using polyTHFs with various M(n)s and end groups, as well as other polyethers as the guest polymers, was examined.  相似文献   

17.
Fullerenehasgeneratedarapidlygrowingandactiveresearchareal.InclusioncomplexesoffullerenehavebeenpreparedforCoowithavarietyofhostsystemsincludingcalixarenes,cyclotriveratrylene,andy-cyclodextrin.TheselectiveformationofaclathratefromCooandcall-c[8]areneswasexcellentlyutilizedfortheseparationofCooandC,,'.HereinwereportthatCoocanbeincludedinthecavityofanewkindoffunctionnedcalixlslarene,p-tert-butylcall-c[8]arenetetraphenylether(1).ThefixtureofCooand1(lfZmolarratio)wasrefluxedintoluenefor2--3h,d…  相似文献   

18.
程贤甦  苏英草  关怀民 《化学学报》2000,58(11):1413-1418
通过DSC曲线,IR光谱,电子光谱和XRD谱分析,发现12-钼磷酸与葡聚糖在水溶液中可形成黄色包合物。以ESR,XPS,IR和电子光谱等手段研究此黄色包合物在紫外光照射下的光致变蓝紫色,是由于其光电子转移反应产物多价态钼(Ⅵ,Ⅴ,Ⅳ)配合物呈蓝紫色,而另一产物带部分羰基葡聚糖为无色所致。由DSC曲线,电子光谱,IR光谱和XRD谱测试结果得知,随着光化反应产物的生成,两者分子间产生包合作用,从而提高光致变色的稳定性。  相似文献   

19.
环糊精及其衍生物的超分子晶体结构研究进展   总被引:13,自引:0,他引:13  
本文对近年来有关环糊精、环糊精衍生物以及它们与各类客体组装成的超分子包合物的晶体结构研究进行的简要概述。  相似文献   

20.
朱峰  郭文生  林永成 《有机化学》2001,21(9):655-657
按文献方法合成了一个螯形主体分子,反式-9,10-二氢-9,10-二(1-萘基)-9,10-菲二醇。研究发现该主体可以和一些含氮杂环化合物形成一定比例的晶体包合物。用X-射线衍射分析二环己胺包合物的晶体结构表明,包合物中主客体之间存在O-H…N氢键相互作用,客体分子包合在主体分子形成的空腔中。  相似文献   

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