共查询到20条相似文献,搜索用时 62 毫秒
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合成了一个苯并21-冠-7-柱[5]芳烃杂二主题主体分子(1),二级铵盐是21-冠-7大环的合适客体,而柱[5]芳烃空腔可以强络合中性客体基元5-(1H-1,2,3-triazol-1-yl)pentanenitrile(TAPN),因此选择含有2个TAPN的客体2和含有2个二级铵盐的客体3作为连接体,依靠二级铵盐?21-冠-7和中性客体?柱[5]芳烃正交主客体作用,构筑了一个三组分超分子聚合物(1,2和3的摩尔比为1∶0.5∶0.5),该组装体的形成得到了1H-NMR、DOSY、黏度和SEM等手段的表征?所构筑的超分子聚集体是浓度依赖的,其形成超分子聚合物的临界浓度为49 mmol/L. 相似文献
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Sheng-Nan Lei Prof. Dr. Hongyan Xiao Prof. Dr. Yi Zeng Prof. Dr. Chen-Ho Tung Prof. Dr. Li-Zhu Wu Prof. Dr. Huan Cong 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(25):10145-10151
Although highly useful in supramolecular chemistry, pillararenes lack a fluorophore in their skeleton. Here we present BowtieArene, a novel fluorescent dual macrocycle, featuring a central tetraphenylethylene-derived fluorophore and two pillar-like, pentagon-shaped cavities which are comparable to pillar[5]arene. This concisely prepared, figure-of-eight molecule exhibits vapor absorption and host–guest capabilities, as well as intriguing switchable fluorescence. The fluorochromism of BowtieArene can be triggered by multiple external stimuli including solvent, vapor, and mechanical force, with excellent reversibility and stability. Experimental and theoretical evidence indicate that the fluorochromism should be closely related to molecular packing. 相似文献
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Sheng‐Nan Lei Hongyan Xiao Yi Zeng Chen‐Ho Tung Li‐Zhu Wu Huan Cong 《Angewandte Chemie (International ed. in English)》2020,59(25):10059-10065
Although highly useful in supramolecular chemistry, pillararenes lack a fluorophore in their skeleton. Here we present BowtieArene, a novel fluorescent dual macrocycle, featuring a central tetraphenylethylene‐derived fluorophore and two pillar‐like, pentagon‐shaped cavities which are comparable to pillar[5]arene. This concisely prepared, figure‐of‐eight molecule exhibits vapor absorption and host–guest capabilities, as well as intriguing switchable fluorescence. The fluorochromism of BowtieArene can be triggered by multiple external stimuli including solvent, vapor, and mechanical force, with excellent reversibility and stability. Experimental and theoretical evidence indicate that the fluorochromism should be closely related to molecular packing. 相似文献
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Dr. Zhiou Li Dr. Yoshihisa Sei Prof. Munetaka Akita Dr. Michito Yoshizawa 《化学:亚洲杂志》2014,9(4):1016-1019
A fluorescent macrocycle containing four anthracene panels linked by meta‐phenylene spacers and amino hinges was synthesized. The macrocycle adopts a twisted, compressed conformation that places embedded anthracene fluorophores in close contact. Emission from the convoluted macrocycle is highly solvatochromic and significantly enhanced as compared with that of the partial structures. 相似文献
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Yiliang Wang Liu-Pan Yang Xiang Zhao Lei Cui Jian Li Xueshun Jia Jianhui Fang Chunju Li 《Molecules (Basel, Switzerland)》2020,25(24)
Conformational exchanges of synthetic macrocyclic acceptors are rather fast, which is rarely studied in the absence of guests. Here, we report multiple stimuli-responsive conformational exchanges between two preexisting conformations of 2,2′,4,4′-tetramethoxyl biphen[3]arene (MeBP3) macrocycle. Structures of these two conformations are both observed in solid state, and characterized by 1H NMR, 13C NMR and 2D NMR in solution. In particular, conformational exchanges can respond to solvents, temperatures, guest binding and acid/base addition. The current system may have a role to play in the construction of molecular switches and other stimuli-responsive systems. 相似文献
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Hong Wang Wenjuan Chen Yuejun Zhu Hao Yan Jian Zhang Chengzhong Wang 《Journal of Dispersion Science and Technology》2016,37(9):1341-1348
In this paper, we report the synthesis and characterization of a new stimuli-responsive diblock polymer, i.e., methoxy poly (ethylene glycol)-block-Poly(N-isopropylacrylamide) (mPEG-b-PNIPAM), which belongs to the family of supramolecular amphiphiles. For this purpose, β-cyclodextrin (β-CD)-functionalized methoxy poly (ethylene glycol) (mPEG-CD) and adamantine (AD)-modified poly(N-isopropylacrylamide) (PNIPAM-AD) were synthesized. The diblock polymer mPEG-b-PNIPAM was then obtained by host–guest inclusion between mPEG-CD and PNIPAM-AD. The structure and molecular weight of the mPEG-b-PNIPAM was confirmed by 1HNMR and GPC, respectively. Above the lower critical solution temperature (LCST), mPEG-b-PNIPAM can self-assemble into nano-structures in aqueous solutions with PNIPAM block as the core and mPEG block as the corona. The aggregation behavior of mPEG-b-PNIPAM were revealed by UV-vis, DLS measurements, and TEM observations. The mPEG-b-PNIPAM was further utilized to construct Dox@mPEG-b-PNIPAM micelles at 37°C in phosphate-buffered saline (PBS). No detectable amount of Dox was released from the micelles at 37°C. When cooling to 27°C or adding a competitive reagent, however, release of Dox from the micelles was observed. 相似文献
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Multidrug resistance of cancer cells is a major obstacle for cancer chemotherapy. Herein, we present a nanocarrier that can release chemotherapeutic agents to induce tumor cell death and generate NO under NIR to overcome multidrug resistance in cancer chemotherapy. Owing to the unique structure of the water channel in this controlled release system for chemotherapeutic agents, the nanocarrier surface is equipped with more active sites to graft NO donor molecules. The released NO performs very well in reversing multidrug resistance by inhibiting P-gp expression. Our findings provide new insight into multidrug resistance cancer therapy and controlled release nanocarriers for multiple drugs. 相似文献
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采用聚乙二醇单甲醚(mPEG)为亲水段,聚赖氨酸(PzLL)为疏水段,通过二硫键和碳氮双键串联桥连合成了两嵌段共聚物(mPEG-CN-SS-PzLL),其中的二硫键具有还原敏感性,碳氮双键具有pH酸敏感性。通过红外光谱和核磁共振谱等手段测试分析了产物的化学结构。将聚合物通过透析法自组装制备得到双刺激响应型纳米载药粒子。结果表明:该纳米载药粒子的药物包封率较高,达到52%。该载药系统在还原环境或酸性环境下具有良好的体外释药性能。 相似文献
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Sanjay Pal Michael Kather Sovan Lal Banerjee Pabitra Saha Andrij Pich Nikhil K. Singha 《Journal of polymer science. Part A, Polymer chemistry》2020,58(6):843-851
This investigation describes the synthesis of a dual stimuli-responsive, amphiphilic ABC tri-block copolymer (BCP) based on the functional monomers via RAFT polymerization. In this case, ABC-type BCP was prepared based on N-isopropylacrylamide, n-butyl acrylate, and 4-vinylpyridine in DMF solvent using cyanomethyl dodecyl trithiocarbonate as the RAFT agent and azobisisobutyronitrile as a thermal initiator in a subsequent macro-RAFT approach, respectively. The BCPs were characterized by SEC, 1H-NMR, FTIR spectroscopy, and DSC analyses. Temperature and pH-dependent properties of the smart BCP micelles in aqueous medium were investigated using dynamic light scattering. Transmission electron microscopic images were taken at cryogenic and dry conditions to study the morphology of molecular assemblies of block copolymers in an aqueous medium. The phase and topographical images were captured by atomic force microscopy to understand the assembly of block copolymers in solvents of different polarities. The morphology of BCP micelles was transformed from flower-like to spherical in the presence of solvents with different polarities (H2O or CHCl3). 相似文献
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Click-Formed Polymer Gels with Aggregation-Induced Emission and Dual Stimuli-Responsive Behaviors 下载免费PDF全文
Stimuli-responsive polymer gels have recently attracted great attention due to their heat/solvent resistance, dimensional stability, and unique sensitivity to external stimuli. In this work, we synthesized thiol-functionalized tetraphenylethylene (TPE) and constructed polymer gels through thiol-ene click reaction. The synthetic process of the polymer gels could be monitored by fluorescence emission of TPE moieties based on aggregation-induced emission mechanism. In addition, due to the dual redox- and acid responsiveness of the polymer gels, in the presence of dithiothreitol and trifluoroacetic acid, fluorescence quenching of the polymer gels can be observed. This stimuli-responsive characteristics endows the polymer gels with potential applications in fluorescent sensing and imaging, cancer diagnosis and selfhealing materials. 相似文献
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《化学通报》2015,(9)
以正硅酸四乙酯(TEOS)为硅源,制备介孔二氧化硅纳米微球(MSNs),利用原子转移自由基聚合(ATRP)技术在MSNs表面接枝聚甲基丙烯酸二甲氨基乙酯(PDMAEMA),以其作为缓释开关,构成智能纳米容器(MSNs-PDMAEMA)。通过在其中装载防腐蚀剂苯并三唑(BTA)来验证其双重刺激响应性释放性能。采用透射电子显微镜、热重分析、X-射线光电子能谱以及傅里叶变换红外光谱表征了MSNs的结构、形貌及表面功能化过程,并使用荧光光谱仪实时监测BTA在不同p H、温度下的释放过程。结果表明,智能纳米容器掺杂于Si Ox/Zr Oy中实现了BTA的双重响应性释放,形成Cu-BTA复合膜,起到铜金属防腐蚀的作用。 相似文献