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1.
聚乙二醇/甲基丙烯酸β羟乙酯水凝胶的合成及其表征   总被引:1,自引:0,他引:1  
以偶氮二异丁腈(AIBN)为引发剂,N,N'-亚甲基双丙烯酰胺(BIS)为交联剂,采用自由基聚合法合成了聚乙二醇(PEG)/甲基丙烯酸β-羟乙酯(HEMA)水凝胶.应用傅立叶转换红外光谱(FT-IR)研究了水凝胶分子间的相互作用,结果表明PEG和HEMA间存在较强的分子闻氢键.  相似文献   

2.
基于弱氢键相互作用形成的层状有机超分子晶体   总被引:11,自引:0,他引:11  
合成了双吡啶双西佛碱(bped)有机分子,并用该分子进行了超分子网络晶体的组装.X射线单晶结构分析结果表明,该晶体属单斜晶系,P2(1)/c空间群,晶胞参数为a=1.340 14(15)nm,b=0.421 53(11)nm,c=1.115 05(4)nm,β=101.660(4)°,V=0.616 90(18)nm3,Z=2,R=0.064 8.在bped晶体中存在着分子间氢键相互作用,该氢键由N原子和H—C中的H原子相互作用而成.每一个bped分子同另外6个bped分子通过氢键相连,构成了二维层状结构.  相似文献   

3.
利用傅立叶变换红外光谱和傅立叶变换拉曼光谱研究了牛血清白蛋白(BSA)与双亲嵌段共聚物P103作用过程中蛋白质构象的变化规律。研究表明,当P103浓度较低时,BSA二级结构变化不大,当P103浓度为16 g/L或以上时,α-螺旋结构由45.9%降至40%以下,β-折叠结构升高,由6.1%增至17%左右,同时无规结构略微下降。P103的加入主要改变BSA分子内部氢键的结合方式,使α-螺旋结构转变为β-折叠结构;P103的加入还影响BSA中氨基酸侧链的微环境变化和蛋白质二硫键的构象变化。  相似文献   

4.
分子间相互作用在生物和材料等科学中发挥着关键作用,研究分子间相互作用的本质意义重大。氢键是分子间相互作用的一种主要形式,在确定分子构象和晶体结构以及生物分子尤其是核酸和蛋白质的结构功能中起着重要作用[1-3]。苯甲酸衍生物广泛存在于生物大分子内,与生物活性离子通过氢键作用等改变生物活性分子的活性功能,研究苯甲酸衍生物分子间氢键相互作用对于了解生物体内的化学现象具有重要意义。研究表明菱角的抗肿瘤作用明显,实验上已经从菱角中成功提取了活性单体化合物:3,4,5-三羟基苯甲酸二聚体[4],理论研究标题化合物的氢键结构与氢…  相似文献   

5.
许多研究表明,在蛋白质-水体系中由于蛋白质分子和水分子间的相互作用,使蛋白质周围的水的性质和状态发生了变化,其中一部份水分子以氢键与蛋白质分子表面的极性基因相结合,成为不冻结水(在我们的实验条件下,冷却至-40℃仍不冻结的水),而另一部份  相似文献   

6.
黄翠英  李阳  王长生 《化学进展》2012,(6):1214-1226
N-H…O=C、C-H…O=C、N-H…N和C=H…N等氢键作用是蛋白质α-螺旋结构、β-折叠结构和DNA双螺旋结构形成的主要因素,在生物分子识别、蛋白质复制以及遗传信息传递等过程中起重要作用。准确快速计算生物体系中存在的N-H…O=C、C-H…O=C、N-H…N和C-H…N等氢键作用强度以及氢键强度随分子几何结构(距离和角度)变化的势能曲线对正确模拟(从而正确认识和理解)蛋白质折叠机制和DNA双螺旋结构形成机制等生物过程意义重大,对设计合成具有特殊功能的生物分子材料有重要指导价值。本文主要介绍了近年来建立的偶极-偶极氢键作用模型及其在快速预测多肽-多肽分子间和核酸碱基-多肽分子间氢键作用强度和氢键作用势能曲线方面的应用。  相似文献   

7.
用荧光光谱滴定法测定了单-[6-(二乙烯三胺)-6-脱氧]-β-环糊精(1)、单-[6-(三乙烯四胺)-6-脱氧]-β-环糊精(2)及其铜配合物(3,4)与一系列萘衍生物在磷酸缓冲溶液(pH7.2,0.1mol.dm^-^3)中,25℃时形成超分子体系的稳定常数,并与母体β-环糊精的配位能力进行了比较。化学计量法表明,四种化学修饰β-环糊精与萘衍生物形成了1:1的超分子配合物。从尺寸适合、几何互补及多点识别等方面讨论了主体化合物对模型底物的分子选择性键合能力。结果表明,疏水相互作用、范德华力、静电相互作用及氢键等多种非共价键弱相互作用协同贡献于超分子配合物的形成,主-客体间的结构匹配在分子受体选择性键合底物形成超分子配合物中起重要作用。  相似文献   

8.
尤长城  张Min  刘育 《化学学报》2000,58(3):338-342
用荧光光谱滴定法测定了单-[6-(二乙烯三胺)-6-脱氧]-β-环糊精(1)、单-[6-(三乙烯四胺)-6-脱氧]-β-环糊精(2)及其铜配合物(3,4)与一系列萘衍生物在磷酸缓冲溶液(pH7.2,0.1mol.dm^-^3)中,25℃时形成超分子体系的稳定常数,并与母体β-环糊精的配位能力进行了比较。化学计量法表明,四种化学修饰β-环糊精与萘衍生物形成了1:1的超分子配合物。从尺寸适合、几何互补及多点识别等方面讨论了主体化合物对模型底物的分子选择性键合能力。结果表明,疏水相互作用、范德华力、静电相互作用及氢键等多种非共价键弱相互作用协同贡献于超分子配合物的形成,主-客体间的结构匹配在分子受体选择性键合底物形成超分子配合物中起重要作用。  相似文献   

9.
用荧光光谱滴定法测定了单-[6-(二乙烯三胺)-6-脱氧]-β-环糊精(1)、单-[6-(三乙烯四胺)-6-脱氧]-β-环糊精(2)及其铜配合物(3,4)与一系列萘衍生物在磷酸缓冲溶液(pH 7.2,0.1 mol·dm-3)中,25℃时形成超分子体系的稳定常数,并与母体β-环糊精的配位能力进行了比较.化学计量法表明,四种化学修饰β-环糊精与萘衍生物形成了1:1的超分子配合物.从尺寸适合、几何互补及多点识别等方面讨论了主体化合物对模型底物的分子选择性键合能力.结果表明,疏水相互作用、范德华力、静电相互作用及氢键等多种非共价键弱相互作用协同贡献于超分子配合物的形成,主-客体间的结构匹配在分子受体选择性键合底物形成超分子配合物中起重要作用.  相似文献   

10.
设计合成了一种中心为三乙基氨基,酰胺基作为氢键连接基团,柔性的烷基链连接偶氮苯基团的含多种分子间弱相互作用的三枝状有机凝胶因子1.由于偶氮苯基团处于分子的外缘,在THF溶液中,凝胶因子1表现出良好的光致变色行为.凝胶性能测试中,分子间存在氢键作用、π-π相互作用等使得该化合物在醇类、有机酸类和乙腈等极性溶剂中极易形成稳定的有机凝胶.在少数的非极性溶剂,如正己烷和环己烷中也可以形成稳定凝胶,并且随着溶剂极性的不同,凝胶形貌呈现出规则的纤维状或带状结构.  相似文献   

11.
HEPT类化合物的QSAR研究   总被引:3,自引:0,他引:3  
章文军  许禄 《应用化学》2001,18(9):717-0
为定量结构/活性相关性研究提取了量子化学参数,拓扑指数Am,分子连接性指数^mxt及疏水性常数,同时应用正交变换和最佳变量子集算法(Leaps-and-Bonds)进行了变量压缩和选择,进而实施了多元回归分析,并由此结果进行了HEPT类化合物(1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)-thymine derivatives)的结构/活性关系的理论解释,进行了人工神经网络法对于该类化合物的活性预测,其结构明显好于多元回归法。  相似文献   

12.
Similarity of the extrusion curves of non-wetting liquid in a nanoporous medium with different initial fill volume fractions is observed experimentally. The similarity can be explained by the scaling of the interface energy and the self-similarity of the infinite percolation cluster of fluid-filled pores. Understanding the physical processes leading to the observed phenomena is a foundation for the development of high-performance devices for damping and energy storage on the basis of such heterogeneous systems.  相似文献   

13.
The content of the fine and ultrafine particles in the raw material results in difficulty of the separation, the loss of the valuable components and ecological contamination. Secondary using of the fine particles is impossible without their granulation. This problem has been solved by the agglomeration-in-liquid method.An agglomeration-in-liquid method is a process to produce agglomerates in a liquid phase from solid particles suspended in the liquid. The surface of solid particles and the binding liquid must be of identical polarity, but the continuous phase must be of the opposite polarity. The water solutions of the surfactant are the binding liquids or the organic liquids.  相似文献   

14.
The synthesis and liquid crystalline behaviour of the first and second generations of a dendrimeric structure based on poly(propyleneimine)(DAB-dendr(NH2)x) are reported. 4-(4-n-Alkoxybenzoyloxy)salicylaldehydes are used as mesogenic moieties attached at the peripheral amino groups of the dendrimers giving rise to dendromesogens with four and eight mesogenic branches. From these dendromesogens, considered as organic ligands, were prepared six metal-containing dendrimers which incorporate two or four copper atoms in their structures. All the dendrimeric ligands and three of the metal-containing dendrimers exhibit liquid crystalline properties which were studied by optical microscopy, DSC, X-ray diffraction and EPR spectroscopy.  相似文献   

15.
用电势阶跃法和旋转圆盘电极法(RDE)以及SEM和XRD测试手段,初步研究了光亮剂双氰化体系中银电沉积行为的影响,研究表明,光亮剂的加入并未导致银电沉各成核机理的改变,但显著增强了镀液的微观平整效应,并且所得镀层的表现光滑程度明显改善,XRD测试亦同时表光亮剂的加入并未改变镀层的择优取向。  相似文献   

16.
The dependence of the critical supersaturation on the degree of the initial undersaturation has been analyzed in detail.This dependence is explained by means of the Richarch-Powell equation, taking into account the dependence of the -ratio upon the partial pressures of the inert gas and the liquid under investigation.  相似文献   

17.
An approximated hardness kernel, which includes the second derivative with respect to the density of the kinetic energy, the electron-electron coulomb repulsion, and the exchange density functionals, has been tested for the calculation of the global hardness. The results obtained for a series of 40 cations and neutral systems and 16 anions represent in most cases an improvement of the results obtained using the HOMO-LUMO gap approach and indicate the viability of this approach to evaluate global hardness. In addition, the relevance of the Fukui function approximation and the role of the three components of the hardness kernel in the evaluation of the global hardness have been analyzed.  相似文献   

18.
Abstract

Thermodynamic and transport properties of pure liquid metals show interesting correlations near the melting temperature. This is well known for the case of the surface tension σ and the shear viscosity η In this paper we investigate the possible extension of these correlations to binary alloys, taking the FeB alloy as a case study. Based on literature data we analyze the variation of σ and η as a function of temperature and concentration in a deep eutectic region of the phase diagram of this alloy, as well as the possible correlations between those two quantities. Substantial differences with respect to the behavior in pure metals are found.  相似文献   

19.
A straightforward modification of the resolution of the identity (RI) approximation to the Coulomb interaction is described. In the limit of basis sets that are dominated by high angular momentum functions the observed speedups in realistic test systems reach a factor of 2 compared to the standard RI algorithm, and a factor of up to 300 compared to the standard algorithm to form the Coulomb matrix. More moderate savings on the order of 0-20% are obtained for the more commonly used smaller basis sets. A series of test calculations is reported to illustrate the efficiency of the algorithm.  相似文献   

20.
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