共查询到19条相似文献,搜索用时 93 毫秒
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气相色谱中的超分子化学问题:Ⅰ.气相色谱与超分子化学的关系 总被引:1,自引:3,他引:1
超分子化学是有关超分子体系结构和功能的化学,超分子体系是由多个分子作用联系起来的实体,分子识别是形成超分本系的基本特征,本文从分子识别的角度,探讨了气相色谱学中超分子化学问题,并详细地评述了冠醚、液晶、环表固定液的分子识别机理的研究状况,最后,作者们大致展望了色谱研究超分子问题的前景,并且认为在多人工作基础上会产生一门新科学-超分子色谱学。 相似文献
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分子调控的概念及其意义 总被引:1,自引:0,他引:1
在分子识别的基础之上提出了分子调控的新概念,指出分子调控是外界因素对分子某些性质的指令性干预,是超分子体系所持有的功能,通过这种调控作用,可以有意识、有目的地控制分子的行为,并列举若干实例加以说明。 相似文献
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计算机分子模拟在分子印迹技术中的应用 总被引:1,自引:0,他引:1
传统的分子印迹技术对模板分子、功能单体、交联剂、致孔剂等的筛选往往依靠经验,常通过反复实验对合成条件进行优化,存在实验周期长、耗材量大等问题。计算机分子模拟技术的应用在实验过程中起到可预见性指导作用,可以实现精准识别位点的裁制、识别驱动力的设计,通过结合能等物化特征参数计算优化识别体系的稳定性,从而合理选择模板分子、功能单体、交联剂、致孔剂,优化聚合条件,以提高聚合物识别特异性和亲和力,缩短实验周期,更符合绿色化学的理念。本文简单介绍了计算机分子模拟技术,重点对其在分子印迹技术中的指导作用进行了综述,并对其在分子印迹技术中的应用进行了展望。 相似文献
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评述了液晶态分子在分析化学中的应用进展,包括其超分子的分子识别作用,液晶在色谱,光谱探针,核磁共振谱等分析化学领域中的应用。 相似文献
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在超分子主-客体识别系统中,由专一作用如多重氢键、拓扑捕捉、金属-配体驱动的识别虽然具有高选择性,但要求主体具有严格的尺寸、形状和电子环境;同时识别通常限于那些具有拓扑特征和电子特征的分子,这类识别机制称为静态识别。另一方面,由超支化聚合物衍生的核-壳两亲大分子(CAM),方便易得且有广泛的客体亲合性,但客体选择性通常较低。近年的研究表明,CAM的核经过合适的电子性质改性后,竞争客体分子间的差异可被放大,从而实现高选择性包裹与分离,而CAM最大的特点是核内有大量随机分布的官能团,从而可以进行各种精细的改性。这一由复杂系统的非线性特征导致的识别不需要专一作用的推动,适合于复杂分子的识别,被称为超分子模糊识别。实验表明,超分子模糊识别主体可以用于各种离子客体的高效分离,还可以识别拓扑特征和电子特征非常相似的分子。本文就超分子模糊识别的机制、特点以及应用作了综述。 相似文献
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卤键是一种新的分子间非共价作用力,它存在于卤素原子(路易斯酸)和具有孤电子对的原子或π-电子体系(路易斯碱)之间,在超分子化学、材料科学、生物识别和药物设计等领域已经显示出独特的优势。本文主要从卤键的特征和在化学传感和分子识别中的应用以及发展前景等几方面进行了介绍,期望引起人们对卤键的更多关注。 相似文献
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Many biomolecules exist as internal ion pairs or zwitterions within a biologically relevant pH range. Despite their importance, the molecular recognition of this type of systems is specially challenging due to their strong solvation in aqueous media, and their trend to form folded or self‐assembled structures by pairing of charges of different sign. In this Minireview, we will discuss the molecular recognition of zwitterions using non‐natural, synthetic receptors. This contribution does not intend to make a full in‐depth revision of the existing research in the field, but a personal overview with selected representative examples from the recent literature. 相似文献
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Jean-Marie Lehn 《Journal of Chemical Sciences》1994,106(5):915-922
The article discusses molecular recognition and overviews the key concepts -storage and retrieval of chemical information
by molecular structures, supramolecular reagents and catalysts, molecular transport, semiochemistry and self assembly. The
prospects of controlling supramolecular architecture through engineered molecular recognition and design of ‘programmed systems’
controlled by molecular information are also discussed. 相似文献
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Jean-Marie Lehn 《Angewandte Chemie (International ed. in English)》1990,29(11):1304-1319
The selective binding of a substrate by a molecular receptor to form a supramolecular species involves molecular recognition which rests on the molecular information stored in the interacting species. The functions of supermolecules cover recognition, as well as catalysis and transport. In combination with polymolecular organization, they open ways towards molecular and supramolecular devices for information processing and signal generation. The development of such devices requires the design of molecular components performing a given function (e.g., photoactive, electroactive, ionoactive, thermoactive, or chemoactive) and suitable for assembly into an organized array. Light-conversion devices and charge-separation centers have been realized with photoactive cryptates formed by receptors containing photosensitive groups. Eleclroactive and ionoactive devices are required for carrying information via electronic and ionic signals. Redox-active polyolefinic chains, like the “caroviologens”, represent molecular wires for electron transfer through membranes. Push-pull polyolefins possess marked nonlinear optical properties. Tubular mesophases, formed by organized stacking of suitable macro-cyclic components, as well as “chundle”-type structures, based on bundles of chains grafted onto a macrocyclic support, represent approaches to ion channels. Lipophilic macrocyclic units form Langmuir-Blodgett films that may display molecular recognition at the air-water interface. Supramolecular chemistry has relied on more or less preorganized molecular receptors for effecting molecular recognition, catalysis, and transport processes. A step beyond preorganization consists in the design of systems undergoing self-organization, that is, systems capable of spontaneously generating a well-defined supramolecular architecture by self-assembling from their components under a given set of conditions. Several approaches to self-assembling systems have been pursued: the formation of helical metal complexes, the double-stranded helicates, which result from the spontaneous organization of two linear polybipyridine ligands into a double helix by binding of specific metal ions; the generation of mesophases and liquid crystalline polymers of supramolecular nature from complementary components, amounting to macroscopic expression of molecular recognition; the molecular-recognition-directed formation of ordered solid-state structures. Endowing photo-, electro-, and ionoactive components with recognition elements opens perspectives towards the design of programmed molecular and supramolecular systems capable of self-assembly into organized and functional supramolecular devices. Such systems may be able to perform highly selective operations of recognition, reaction, transfer, and structure generation for signal and information processing at the molecular and supramolecular levels. 相似文献
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Jean-Marie Lehn 《Angewandte Chemie (International ed. in English)》1988,27(1):89-112
Supramolecular chemistry is the chemistry of the intermolecular bond, covering the structures and functions of the entities formed by association of two or more chemical species. Molecular recognition in the supermolecules formed by receptor-substrate binding rests on the principles of molecular complementarity, as found in spherical and tetrahedral recognition, linear recognition by coreceptors, metalloreceptors, amphiphilic receptors, and anion coordination. Supramolecular catalysis by receptors bearing reactive groups effects bond cleavage reactions as well as synthetic bond formation via cocatalysis. Lipophilic receptor molecules act as selective carriers for various substrates and make it possible to set up coupled transport processes linked to electron and proton gradients or to light. Whereas endoreceptors bind substrates in molecular cavities by convergent interactions, exoreceptors rely on interactions between the surfaces of the receptor and the substrate; thus new types of receptors, such as the metallonucleates, may be designed. In combination with polymolecular assemblies, receptors, carriers, and catalysts may lead to molecular and supramolecular devices, defined as structurally organized and functionally integrated chemical systems built on supramolecular architectures. Their recognition, transfer, and transformation features are analyzed specifically from the point of view of molecular devices that would operate via photons, electrons, or ions, thus defining fields of molecular photonics, electronics, and ionics. Introduction of photosensitive groups yields photoactive receptors for the design of light-conversion and charge-separation centers. Redox-active polyolefinic chains represent molecular wires for electron transfer through membranes. Tubular mesophases formed by stacking of suitable macrocyclic receptors may lead to ion channels. Molecular self-assembling occurs with acyclic ligands that form complexes of double-helical structure. Such developments in molecular and supramolecular design and engineering open perspectives towards the realization of molecular photonic, electronic, and ionic devices that would perform highly selective recognition, reaction, and transfer operations for signal and information processing at the molecular level. 相似文献
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John J. Lavigne Eric V. Anslyn 《Angewandte Chemie (International ed. in English)》2001,40(17):3118-3130
Molecular recognition has evolved from a science designed to understand biological systems into a much more diverse area of research. While work continues to elucidate “nature's tricks” with respect to intermolecular interactions, much attention has turned to the perspective that molecular recognition, by design, can lead to new technologies. Applications ranging from molecular sensing to information storage and even working molecular machines have been envisioned. This review will highlight a few historical hallmarks of molecular recognition oriented at studying the basic science of intermolecular interactions, but then detail recent advances in molecular recognition aimed towards applications in the field of molecular sensing. Rational design can be used to create synthetic receptors with a good deal of predictability and selectivity, and many signal transduction mechanisms exist for converting these receptors into sensors. This is the first topic discussed. The concept of “differential” or “generalized” sensing is then presented, where one uses an array of sensors that do not necessarily conform to the “lock and key” principle. This approach to sensing is inspired by the mammalian senses of taste and smell, which we briefly describe. To mimic senses of taste and smell, one is naturally led to the use of combinatorial libraries, a direction of research that has seen continued growth over the past few years. We summarize the current state of the art in synthetic combinatorial receptors/sensors, and then predict a future direction that the field of molecular recognition will possibly take. The review is not meant for the specialist, but instead for a general audience. It does not present a highly detailed analysis of each individual topic: synthetic receptors, sensors, olfaction/gustation, and combinatorial receptors/sensors. Instead, this review shows how all these fields complement each other and fit together to create sensing devices. Our conclusion is that specific analyte sensing, differential sensing, and combinatorial chemistry can and will be combined to create sensor arrays, and give the subfield of molecular recognition that uses synthetic systems a bright future in this type of sensing scenario. 相似文献
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Acid‐Base Switchable [2]‐ and [3]Rotaxane Molecular Shuttles with Benzimidazolium and Bis(pyridinium) Recognition Sites 下载免费PDF全文
Prof. Dr. Kelong Zhu Dr. V. Nicholas Vukotic Prof. Dr. Stephen J. Loeb 《化学:亚洲杂志》2016,11(22):3258-3266
For the purpose of developing higher level mechanically interlocked molecules (MIMs), such as molecular switches and machines, a new rotaxane system was designed in which both the 1,2‐bis(pyridinium)ethane and benzimidazolium recognition templating motifs were combined. These two very different recognition sites were successfully incorporated into [2]rotaxane and [3]rotaxane molecular shuttles which were fully characterized by 1H NMR, 2D EXSY, single‐crystal X‐ray diffraction and VT NMR analysis. By utilizing benzimidazolium as both a recognition site and stoppering group it was possible to create not only an acid/base switchable [2]rotaxane molecular shuttle (energy barrier 20.9 kcal?mol?1) but also a [3]rotaxane molecular shuttle that displays unique dynamic behavior involving the simultaneous motion of two macrocyclic wheels on a single dumbbell. This study provides new insights into the design of switchable molecular shuttles. Due to the unique properties of benzimidazoles, such as fluorescence and metal coordination, this new type of molecular shuttle may find further applications in developing functional molecular machines and materials. 相似文献
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Intermolecular interactions in solution play an important role in molecular recognition, which lies at the heart of supramolecular and combinatorial chemistry. Diffusion NMR spectroscopy gives information over such interactions and has become the method of choice for simultaneously measuring diffusion coefficients of multicomponent systems. The diffusion coefficient reflects the effective size and shape of a molecular species. Applications of this technique include the estimation of association constants and mapping the intermolecular interactions in multicomponent systems as well as investigating aggregation, ion pairing, encapsulation, and the size and structure of labile systems. Diffusion NMR spectroscopy can also be used to virtually separate mixtures and screen for specific ligands of different receptors, and may assist in finding lead compounds. 相似文献