对称四甲基六元瓜环与2-氨基甲基吡啶相互作用的研究

分别用核磁共振、紫外可见吸收和X射线单晶衍射方法研究对称四甲基六元瓜环与2-氨基甲基吡啶的相互作用及其结构特征. ¹H NMR谱图和紫外可见吸收光谱图清晰表明, 2-氨基甲基吡啶与对称四甲基六元瓜环有明显的相互作用, 客体2-氨基甲基吡啶的吡啶环部分进入了瓜环空腔, ¹H NMR谱图相关质子峰的积分强度以及客体吸光度随主体瓜环浓度变化明确表示它们之间形成了1∶1的包结配合物, 此包结比并不随瓜环的浓度增加而改变. X射线单晶衍射法对包结配合物晶体的测定进一步证实了核磁共振、紫外可见吸收方法所得结论.     

Comparative analysis of the clathrate forms of syndiotactic polystyrene,poly (p-methylstyrene) and poly (m-methylstyrene)

The crystal structures of the clathrate forms of syndiotactic polystyrene (s-PS), poly (p-methylstyrene) (s-PPMS) and poly (m-methylstyrene) (s-PMMS) containing guest molecules having widely different steric hindrance are compared in detail. Common features and differences concerning the packing of the chains, the shape and the dimensions of the cavities and the stability of the forms deprived of the guest molecules are pointed out. A new clathrate form of s-PPMS containing CS₂ is also described.     

六、七、八元瓜环与苯胺系列衍生物的相互作用

利用紫外吸收光谱、荧光光谱以及¹H NMR方法详细考察了六、七、八元瓜环(Q[6], Q[7], Q[8])与苯胺系列衍生物客体的相互作用和体系pH对其作用的影响. 实验结果表明, 3种瓜环与苯胺系列衍生物客体的相互作用强弱、作用比例以及作用模式与体系的酸度密切相关: 在“高”或“低”pH条件下, 未观察到瓜环与这些客体的明显作用; 在介于“高”与“较高”或“低”与“较低”的pH范围, 瓜环与这些客体发生相互作用, 形成1∶1的包结配合物; 而在介于“较高”与“较低”的pH范围, 瓜环与这些客体发生相互作用, 可形成1∶2的包结配合物. 对于不同的瓜环-客体作用体系, 相应的pH范围各不相同. 本文利用简便的实验方法, 测试了这些pH值及其范围. 根据测定的结果, 结合瓜环以及客体的结构特征, 对体系主客体在不同的酸度区域表现出的不同作用模式进行了探讨.     

Birefringence of binary liquid crystalline mixtures of MBBA and PPMAECOBA in TCM,interferometric assessment

Abstract

The mutual influence of two mesogenic components, namely a nematic liquid crystal N-(p-methoxy-bezylidene)-butylaniline (MBBA) and a lyotropic liquid crystal poly-(phenyl-methacrylic) ester of cetyloxybenzoic acid (PPMAECOBA) in tetra-chloromethane (TCM) is studied in this paper. The ordinary and extraordinary refractive indices of the mixtures, nematic liquid crystal and lyotropic liquid crystal were measured at 589.3?nm with a Rayleigh interferometer and some electro-optical parameters were computed. The main refractive indices, the birefringence, the main normalized polarizabilities and their difference are dependent on the mixture volumetric concentrations, proving the existence of the collective orientational interactions between the two types of liquid crystals.     

杯芳烃和柱芳烃桥梁部位的衍生及其功能化

随着大环化学的快速发展,对杯芳烃、柱芳烃及其他类似化合物的桥梁亚甲基部位进行高效修饰的方法日益引起人们的关注.桥梁部位修饰后的大环衍生物,在不改变其原有属性的基础上增加了新的功能,不仅可以引入更多的功能基团,而且可以通过主客体的自组装行为,进一步拓展杯芳烃和柱芳烃等超分子大环在药物递送、化学传感、荧光体系构建等诸多领域...     

光谱法研究体系pH对七、八元瓜环与萘胺异构体相互作用的影响

利用紫外吸收光谱方法和1H NMR技术考察了体系pH对七、八元瓜环(Q[7],Q[8])与萘胺异构体的相互作用的影响。实验结果表明,Q[7]与萘胺异构体在-0.3＜pH＜8范围内均是以主客体物质的量之比为1∶1的方式相互作用,在8＜pH＜14的范围内,观察不到相互作用;Q[8]与萘胺异构体相互作用体系在pH为-0.3～14的范围内,呈现了5个作用阶段：在“较高”的pH范围,瓜环与萘胺异构体发生相互作用,形成1∶1的包结配合物;在“较低”的pH范围,主客体存在1∶1和1∶2两种作用模式的竞争;而在介于“较高”与“较低”之间的pH范围,Q[8]与这些客体发生相互作用,形成1∶2的包结配合物。     

An Aggregation‐induced Emission Probe Based on Host–Guest Inclusion Composed of the Tetraphenylethylene Motif and γ‐Cyclodextrin for the Detection of α‐Amylase

α‐Amylase, an essential biomarker in pancreas related diseases and perform a major role in carbohydrates metabolism. Hence, monitoring the dynamic changes of α‐amylase is crucial for better clinical diagnosis of diseases. However, the existing methods are suffered from low sensitivity, time consumption and indirect assay with aid of tool enzyme or inhibitor of competitive substrates, the rapid and non‐destructive sensing of α‐amylase in biological samples was highly desired. In this work, a very simple tetraphenylethylene motif and γ‐cyclodextrin based supramolecular fluometric sensing system was firstly established. This system has no emission signal in aqueous media for the freely rotation of phenyl rings in the cavity of γ‐cyclodextrin, but the AIE residues can be released in to water after the α‐amylase hydrolysing γ‐cyclodextrin, then turn on the fluorescence. In this system, the detection limit is calculated to be 0.007 U mL^?1 in MES buffer with a linear range of 0–0.35 U mL^?1, having excellent selectivity to α‐amylase compared to other proteins. At last, our probe can be applied to the quantitative analysis of α‐amylase in human serum, showing potential in point of care testing.     

基于偶氮功能基的光控超分子组装

偶氮类化合物是一类具有合成简单,异构化速率和转化效率高,耐光漂白的反式-顺式(E/Z)光异构化化合物。由于其光异构特性及其可以与大环主体形成稳定包合物,偶氮类化合物在许多领域展现出巨大的应用潜力。在本篇综述中,我们介绍了近年来偶氮功能基修饰的单环糊精、偶氮苯桥联双环糊精、冠醚衍生物以及偶氮类芳香大环化合物等作为主体,或偶氮苯及其衍生物为客体通过主客体相互作用构筑的光刺激响应的超分子组装体系在拓扑形貌调控、药物传递、智能材料等方面的设计原理、组装机理、应用和发展趋势。同时,我们也讨论了此类超分子组装体发展所面临的机遇和挑战,并希望可以进一步促进智能超分子组装体系的发展。     

Cellular- and Subcellular-Targeted Delivery Using a Simple All-in-One Polymeric Nanoassembly

Nanocarrier-mediated drug delivery is a promising strategy to maximize the power of chemotherapy and minimize side effects. However, current approaches show insufficient drug-loading capacity and inefficient drug release, and require complex modification processes. Attempts to enhance one of these features often compromise other merits. We describe here a block copolymer assembly system that combines desirable characteristics. The design of self-immolative and crosslinkable hydrophobic moieties offer stable and high encapsulation. Redox-triggerable polymer self-immolation promotes drug release by switching the hydrophobic core into completely hydrophilic chains. The reactive amine handles, presented on their surface, allow “plug to direct” modification with targeting ligands. Functionalized nanoassemblies have been programmed to target specific subcellular compartments. The simplicity, versatility, and efficacy of the system open up possibilities for an all-in-one delivery system.     

四苯乙烯衍生物与大环主体在主客体相互作用下的聚集诱导发光

具有聚集诱导发光性质化合物的发展不仅很大程度上解决了传统有机分子发色团在高浓度、固态或者薄膜等形式的聚集状态下荧光猝灭的问题,而且扩展了有机发色团在荧光探针、传感器以及细胞成像等方面的应用。其中,四苯乙烯及其衍生物作为具有聚集诱导发光性质的典型化合物已被广泛应用在材料化学、生物化学等相关研究领域。受此启发,超分子化学家也将这类具有聚集诱导发光性质的四苯乙烯及其衍生物作为研究对象引入到超分子化学的领域,特别是利用大环主体与四苯乙烯客体通过主客体相互作用有效地限制了荧光客体分子的分子内转动或运动,增强了这类超分子体系的发光强度,并为其在刺激响应性传感器、智能探针等方面提供了新思路。本文总结了近年来涉及四苯乙烯衍生物与大环主体通过主客体相互作用形成聚集诱导发光超分子体系的发展,并按照大环主体进行分类简要介绍其应用。