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手性聚合物在手性识别与传感、手性开关、不对称催化和生物医药领域有着重要作用。圆偏振光作为一种手性物理源,由于来源简单易取,操作方便,已经用于诱导构建非手性聚合物的手性结构。在已报道的例子中,圆偏振光诱导主链和侧链聚合物的手性机理完全不同。本综述主要讨论了在膜和溶液聚集体状态下,非手性侧链型偶氮聚合物的光诱导超分子手性和主链共轭聚合物的光诱导轴手性,以及讨论圆偏振光的偏振状态和入射光波长对聚合物手性的影响,归纳总结了已取得的研究进展和作用机制,并对圆偏振光的应用发展前景进行了简要概述。 相似文献
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手性聚合物在手性识别与传感、手性开关、不对称催化和生物医药领域有着重要作用。圆偏振光作为一种手性物理源,由于来源简单易取,操作方便,已经被用于诱导构建非手性聚合物的手性结构。在已报道的例子中,圆偏振光诱导主链和侧链聚合物的手性机理完全不同。本综述主要讨论了在膜和溶液聚集体状态下,非手性侧链型偶氮聚合物的光诱导超分子手性和主链共轭聚合物的光诱导轴手性,并讨论了圆偏振光的偏振状态和入射光波长对聚合物手性的影响,归纳总结了已取得的研究进展和作用机制,并对圆偏振光的应用发展前景进行了简要概述。 相似文献
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超分子螺旋聚合物结合了超分子聚合物制备方法简便、结构及性能可调控等优势,相比于人工合成的共价型螺旋聚合物更接近自然界螺旋生物大分子,因而在手性探针、不对称催化以及手性识别和分离等领域具有广泛的应用前景。结合多肽的手性优势、丰富的二次有序构象及其出色的自组装行为,以多肽作为结构基元经超分子组装制备具有螺旋构象的聚合物,不仅丰富了手性/螺旋聚合物的制备途径,同时为多肽材料的功能化应用提供新的广阔前景。本文综述了多肽基元之间经超分子作用诱导形成的超分子螺旋聚合物,总结了双亲性多肽以及多肽拓扑结构对超分子组装过程的影响及其对形成螺旋结构的控制,重点归纳了由多肽构筑的光、温度、pH、金属离子和酶等不同类型智能响应性的超分子螺旋聚合物。 相似文献
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一种新型联萘基旋光共轭聚合物的圆二色谱和圆偏振荧光光谱 总被引:1,自引:0,他引:1
众所周知 ,聚合物的光电性质依赖于聚合物链的构象和 (或 )组成 ,通过在聚合物上引入手性单元 ,采用圆二色谱 ( CD)和圆偏振荧光光谱 ( CPL)等方法可表征聚合物结构 [1] .近年来 ,由于圆偏振光可用作光数据存储和液晶显示器背景光 [2 ] ,人们开始注重共轭聚合物圆偏振光材料的研究 .共轭聚合物的光致和电致圆偏振光的现象由一种带手性侧链的聚噻吩[3 ] 和一种带手性侧链的聚 (对苯撑乙烯 ) [4 ]产生 ,但它们的圆偏振荧光度 (用不对称因子 glum=2 ( IL-IR) / ( IL+IR)表示 ,IL 和 IR 分别指左圆偏振光强度和右圆偏振光强度 )相对较低 … 相似文献
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手性金属-有机框架具有框架结构多样性和功能可调性等特点,在对映异构体的识别与分离和不对称催化等领域中具有重要的应用.近年来,关于手性金属-有机框架的应用还扩展到其它研究领域,如在圆偏振荧光和手性铁电体等方面的研究中.与非手性金属-有机框架相比,手性金属-有机框架的设计不但要考虑手性的引入途径,还要考虑其结晶与纯化,因此在合成上相对困难.本综述论述了三种构筑手性金属-有机框架的有效策略,包括直接利用手性配体合成、非手性配体的自发拆分或手性模板诱导合成和非手性金属-有机框架的手性化.对近年来手性金属-有机框架在手性分子识别、对映异构体分离、不对称催化、圆偏振荧光以及手性铁电体等方面的研究进展进行了讨论. 相似文献
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Yoshio Okamoto 《Macromolecular Symposia》1996,101(1):343-354
This review mainly describes the asymmetric synthesis of optically active polymers with helical conformation. Bulky methacrylates such as triphenylmethyl methacrylate and 1-phenyldibenzosuberyl methacrylate give one-handed helical and optically active polymers with almost perfectly isotactic main chain conformation by polymerization with chiral anionic initiators. The radical polymerization and copolymerization of these monomers under chiral conditions also afford optically active polymers with prevailing one-handed helicity. N, N-Disubstituted acrylamides also give optically active, helical polymers in the asymmetric anionic polymerization. Optically active polyisocyanates with a prevailing one-handed helical structure have been prepared in the copolymerization of an achiral isocyanate with a small amount of an optically active isocyanate and also in the polymerization of alkyl and aromatic isocyanates with optically active lithium alkoxide or amide compounds. The existence of a stable helical structure for polychloral has been successfully proved with the helical oligomers of chloral. One-handed helical polyisocyanides have been prepared by helix-sense-selective polymerization of bulky isocyanides and also by the cyclopolymerization of a 1, 2-diisocyanobenzene derivative with the Pd complex of a one-handed helical oligomer. 相似文献
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Shu‐Ting Wu Zhen‐Wen Cai Qiao‐Yan Ye Chen‐Hao Weng Xi‐He Huang Xiao‐Lin Hu Chang‐Cang Huang Nai‐Feng Zhuang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(47):13074-13078
Circular dichroism is known to be the feature of a chiral agent which has inspired scientist to study the interesting phenomena of circularly polarized light (CPL) modulated molecular chirality. Although several organic molecules or assemblies have been found to be CPL‐responsive, the influence of CPL on the assembly of chiral coordination compounds remains unknown. Herein, a chiral coordination polymer, which is constructed from achiral agents, was used to study the CPL‐induced enantioselective synthesis. By irradiation with either left‐handed or right‐handed CPL during the reaction and crystallization, enantiomeric excesses of the crystalline product were obtained. Left‐handed CPL resulted in crystals with a left‐handed helical structure, and right‐handed CPL led to crystals with a right‐handed helical structure. It is exciting that the absolute asymmetric synthesis of a chiral coordination polymer could be enantioselective when using CPL, and provides a strategy for the control of the chirality of chiral coordination polymers. 相似文献
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《中国化学快报》2023,34(8):108077
Circularly polarized light (CPL) is an inherently chiral entity and is regarded as one of the possible deterministic signals that led to the evolution of homochirality in earth. Thus, CPL as an external physical field has been widely used in a technique known as absolute asymmetric synthesis, because a product enriched in one enantiomer is formed from racemic precursor molecules without the intervention of a chiral catalyst. In this review, we retrospect the historical research of CPL-induced absolute asymmetric synthesis, including chiral organic molecules, helical polymers, supramolecular assemblies, noble metal nanostructures. However, based on these results, we concluded that the chiral photon-matter interaction is very faint due to the arrangement of molecular bonds giving rise to chiral features, is over a smaller distance than the helical pitch of CPL, leading extremely small enantiomeric excess for product. Therefore, we highlight the recently emerged technology called superchiral field, in which the superchiral far-field and near-field could enhance the dissymmetry of optical field and near-field, respectively. In sum, we hope this review could bring some enlightenment to researchers and further improve the enantioselectivity of CPL-induced absolute asymmetric synthesis. 相似文献
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Yoshio Furusho Eiji Yashima 《Journal of polymer science. Part A, Polymer chemistry》2009,47(20):5195-5207
There is growing interest in the design and synthesis of artificial helical polymers and oligomers, in connection with biological importance as well as development of novel chiral materials. Since the discovery of the helical structure of isotactic polypropylene, a significant advancement has been achieved for synthetic polymers and oligomers with a single helical conformation for about half a century. In contrast, the chemistry of double helical counterparts is still premature. This short review highlights the recent advances in the synthesis, structures, and functions of double helical polymers and oligomers, featuring an important role of supramolecular chemistry in the design and synthesis of double helices. Although the artificial double helices reported to date are still limited in number, recent advancement of supramolecular chemistry provides plenty of structural motifs for new designs. Therefore, artificial double helices hold great promise as a new class of compounds. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5195–5207, 2009 相似文献
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The syntheses of optically active polymers having helical conformation from bulky methacrylates are reviewed focusing on selected topics. The monomers include triphenylmethyl methacrylate and its analogues. Asymmetric anionic polymerization of the monomers gives isotactic, optically active polymers having a helical structure with excess helicity. The isotactic content and the extent of helical‐sense excess depend on the monomer structure and the reaction conditions. In the case of methacrylates, completely isotactic and single‐handed helical polymers can be produced by asymmetric anionic polymerization (helix‐sense‐selective polymerization). Asymmetric radical polymerization is also possible for this class of monomer. Some of the helical polymers show chiral recognition ability toward a wide range of racemic compounds. Polymers having main‐chain configurational chirality are also discussed. 相似文献
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Michiya Fujiki 《Macromolecular rapid communications》2001,22(8):539-563
Controlled synthesis, chiroptical characterization, and manipulation of artificial helical polymers are challenging issues in modern polymer stereochemistry. Although many artificial polymers adopting a preferential screw‐sense helical structure have been investigated, optically active polysilylenes bearing chiral side chains may be among the most suitable to elucidate the inherent nature of the helical structure, since these polymers offer powerful spectroscopic probes as a result of their ideal chromophoric and fluorophoric main chain properties around 300–330 nm. The present paper will review comprehensively the helix‐property‐functionality relationship between side chain structure, global and local main chain conformation, (chir)optical properties, electronic properties, several helical cooperative phenomena, the effects of temperature and solvent polarity, and molecular imaging. This knowledge and understanding of the nature of the polysilylene helix might constitute a bridge between artificial polymers and biopolymers and will assist in designing and controlling new types of helical polymers directed to diverse screw‐sense‐related properties and applications in the future. 相似文献
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George E. Ham 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):1771-1772
Abstract Asymmetric syntheses of optically active polymethacrylate, polyacrylate, polyacrylamide, and polyisocyanate with helical conformation and their chiral recognition abilities are described. 1-Phenyldibenzosuberyl methacrylate (PDBSMA) gave a purely onehanded-helical, optically active polymer ([α]365 +1670 ~ +1780º) with almost perfectly isotactic structure by anionic polymerization using optically active initiators. Radical polymerizations of PDBSMA using chiral initiators, chain transfer agents, and additives also afforded optically active polymers with a prevailing onehanded helicity. Triphenylmethyl acrylate yielded an optically active, helical polymer ([α]365 +102º) having a dyad isotacticity of 70% using an optically active anionic initiator. Although the polyacrylate demonstrated chiral recognition ability as a chiral stationary phase for HPLC, the ability was low mainly because of the low degree of one-handedness. N-(3-Chlorophenyl)-N-phenylacrylamide gave an optically active, helical polymer ([α]365–343º) in the asymmetric anionic polymerization; the polymer had a dyad tacticity of 77%. Optically active polyisocyanates with a predominantly one-handed helical conformation were prepared in homo-and co-polymerization of optically active phenyl isocyanate derivative. These polyisocyanates showed the ability to discriminate enantiomers in solution. 相似文献
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Otto Vogl 《Journal of polymer science. Part A, Polymer chemistry》2011,49(6):1299-1308
The creation of chirality on Earth and the development of chiral life have been discussed in this highlight. Convincing evidence for the introduction of chirality on Earth is still fragmentary. We believe that by a combination of chiral crystallization and formation of helical polymers with preferred chiral conformational structure is the key to this question. This concept of macromolecular asymmetry has inspired ideas and resulted in possible rules for how chiral life as we know it, could have been introduced. These investigations needed the understanding of the requirements for chiral crystallization, for the stereochemistry of the initial formation of helical polymers, the measurements of optical activity of solids and their coordination with the fundamentals of chirality. Spacial modeling of the “oligo‐crystallization” of sodium chlorate led to the conception of “isotactic” linear crystallization, which involves helical propagation. It seems to require unequal sizes of the cations and anions, which, by branching propagation leads to three‐dimensional chiral crystal formation. Linear “isotactic” propagation of crystallization seems to be equivalent to stereo and conformational specific polymerization. One and a half turns of the helix seems to be required for stereo‐ and conformational specificity, that is, between the pentamer and hexamer in chloral polymerization (11/3 or nearly 4/1 helix) and between trimer and tetramer for the sodium chlorate crystal (2/1 helix). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
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This account describes novel artificial double helices recently developed by our group. We have designed and synthesized the double helices consisting of two complementary, m-terphenyl-based strands that are intertwined through chiral amidinium-carboxylate salt bridges. Due to the chiral substituents on the amidine groups, the double helices adopted an excess one-handed helical conformation in solution as well as in the solid state. By extending the modular strategy, we have synthesized double helices bearing Pt(II) linkers, which underwent the double helix-to-double helix transformations through the chemical reactions of the Pt(II) complex moieties. In addition, artificial double-stranded metallosupramolecular helical polymers were constructed by combining the salt bridges and metal coordination. In contrast to the design-oriented double helices based on salt bridges, we have serendipitously developed a spiroborate-based double helicate bearing oligophenol strands. The optical resolution of the helicate was successfully attained by a diastereomeric salt formation. We have also unexpectedly found that oligoresorcinols consisting of a very simple repeating unit self-assemble into double helices with the aid of aromatic interactions in water. Furthermore, a bias in the twist sense of the double helices can be achieved by incorporating chiral substituents at both ends of the strands. 相似文献
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Creation of Circularly Polarized Luminescence from an Achiral Polyfluorene Derivative through Complexation with Helix‐Forming Polysaccharides: Importance of the meta‐Linkage Chain for Helix Formation 下载免费PDF全文
Dr. Tomohiro Shiraki Dr. Youichi Tsuchiya Dr. Takao Noguchi Prof. Shun‐ichi Tamaru Nozomu Suzuki Makoto Taguchi Prof. Michiya Fujiki Prof. Seiji Shinkai 《化学:亚洲杂志》2014,9(1):218-222
A circularly polarized luminescence (CPL) material has been created by polymer–polymer complexation between a helix‐forming polysaccharide, schizophyllan (SPG), and a meta‐phenylene‐linked polyfluorene derivative (mPFS). Computational modeling revealed that mPFS can adopt a helical structure although a conventional polyfluorene derivative with a para‐phenylene linkage tends to enjoy a rigid rodlike conformation. Our detailed experimental examination showed that mPFS forms a chiral nanowire complex through cohelix formation with SPG. We have found, as expected, that this cohelical complex emits highly efficient CPL even in an aqueous solution. The appearance of the high CPL property is due to 1) a high quantum yield of the fluorene unit and 2) immobilization of the helically twisted conformation of mPFS in an isolated manner through cohelix formation with SPG. One can propose, therefore, that the SPG/mPFS complex acts as a new high‐performance CPL material with a solvent‐dispersible nanowire structure. 相似文献