基于氢键的自组装超分子体系

氢键自组装超分子是超分子体系中相对较新颖和引入注意的领域，它在化学和生物体系中占据非常重要的位置。本文主要介绍目前文献报道的一系列由不同氢键缔合方式形成的自组装超分子。     

四重氢键自组装体系的设计与应用

氢键是自然界中最基本的分子间弱相互作用力之一,是构筑超分子自组装体系的理想推动力。近年来,构筑性能优良的多重氢键组装体系已经成为超分子化学的一个热门研究领域。其中,四重氢键组装体系因具有较强的结合力、合成简单、结构易于修饰以及可预测的识别性能等优点,在构筑超分子组装体方面得到了广泛应用。本文综述了四重氢键组装体系的研究进展,重点介绍了各类四重氢键体系的设计思路及其应用。     

三重和四重氢键体系:设计、结构和应用

氢键是超分子化学领域具有特别重要地位的一种非共价作用。近年来,通过氢键自组装制备超分子聚合物已经成为超分子化学的一个热门研究领域。构筑性能优良的多重氢键体系奠定了这个领域的研究基础。其中,三重和四重氢键体系在构筑超分子组装体方面得到了广泛应用。本文综述了三重氢键、四重氢键组装体系的研究进展及其应用,重点介绍了各种三重氢键、四重氢键体系的设计思路和影响其稳定性的各种因素。     

氢键复合物自组装性质的研究

超分子复合物体系因近年来发展较快及应用范围广而颇具吸引力。作为形成超分子复合物的主要手段,氢键自组装对于高分子聚合材料以及生命科学等领域有着重要的意义。本文根据氢键的多重性及不同氢键的缔合方式对氢键复合物进行分类,并对氢键自组装复合物的性质和研究状况作了综述,同时介绍了本研究组在此方面的理论研究工作。     

氢键识别超分子聚合物的新进展

近年来,由于氢键作用对聚合物的热力学性质、微观自组装、结晶及液晶行为的重要影响,氢键识别在超分子聚合物的分子设计与结构控制方面的应用受到广泛关注。本文系统介绍了氢键识别体系的类型与性质,以及分子结构、分子内氢键对氢键识别强度的影响,讨论了羧酸与吡啶间氢键识别体系、与核苷相关的氢键识别体系以及四重氢键识别体系在超分子聚合物中的最新应用,主要介绍了氢键识别超分子聚合物的合成、结构、性质及功能。     

含甲氧基偶氮苯液晶基元超分子的相行为研究

氢键是分子聚集和识别过程中的重要相互作用,利用分子间氢键,可设计并制备各种超分子体系材料,1989年,Kato等报道了吡啶基和羧酸基通过分子间氢键相互作用形成扩展液晶基元,得到了液晶稳定性增强的超分子液晶复合体系及侧链超分子液晶聚合物;同时,Lehn等报道了带脲嘧啶基和2,6-二酰胺吡啶基两种互补官能团的分子通过三重氢键缔合形成的主链超分子液晶。从此,迅速而广泛的开展利用氢键组装的超分子液晶体系的研究,并已组装合成出低分子型、     

氢键在现代化学中的作用

在各种分子间相互作用中,氢键占有很特殊的地位,被称作为超分子化学中的万能相互作用。讨论了氢键在超分子、自组装、分子识别、晶体工程、材料化学和催化过程等现代化学领域中的作用。     

一维超分子体系的研究进展

超分子化学是一个新兴领域,但现今对形成超分子体系所需要的超分子非共价键作用力的理解还不是很全面。文章介绍了几个典型的通过金属配位作用、氢键、π-π堆积、疏水作用和多个非共价键共同作用等自组装的一维超分子体系,以期为超分子的设计提供理论依据。     

[60]富勒烯的超分子自组装研究进展

超分子自组装是发展超分子电子学的重要途径。随着纳米科学和技术的迅速发展,自组装技术已成功地应用于纳米尺度物质的维数、形貌和功能等的调控。作为构筑分子水平上一维、二维、三维有序功能结构和高有序分子聚集态结构的关键技术,超分子自组装技术有力地推动了具有优良光、电、磁性能的分子材料和纳米功能材料更深层次的研究。本文综述了超分子自组装在富勒烯科学领域的基础研究和应用,特别是对有利于自组织和自组装功能的富勒烯基衍生物的设计与合成、超分子作用力引导的具有特定结构的分子体系的可控自组装、以及富勒烯分子聚集态结构材料的光物理过程、超分子中电子转移和能量转移现象进行了描述;并对卟啉、四硫富瓦烯、碗烯和杯芳烃等一系列富π电子化合物和大环主体分子等包含[60]富勒烯的主体化合物的超分子作用和超分自组装体以及通过氢键、π-π作用、静电力和范德华力和金属配位作用形成的[60]富勒烯超分子自组装体进行了总结,对未来发展进行了展望。     

基于横向分子间氢键的棒-线型分子自组装研究进展

棒-线(Rod-Coil)型分子的合成及其自组装行为研究是当前超分子材料研究领域的重要研究方向. 与传统的柔性(Coil-Coil)型嵌段聚合物和Rod-Coil型嵌段聚合物相比, Rod-Coil型分子表现出不同的相行为、自组织特性和微结构, 可以自组装形成多种纳米结构. 研究结果显示, 横向分子间氢键是Rod-Coil型分子自组装形成液晶相和(或)有机凝胶等自组装体的主要驱动力. 主要介绍目前文献报道的横向分子间氢键驱动下的Rod-Coil型分子自组装.     

HYDROGEN BONDING IN POLYMERIC ADSORBENTS BASED ADSORPTION AND SEPARATION

I INTRODUCTION.Ftinctional polymer materials for adsorption and separation are widely used in indtistry,agriculture, hi-tech, national defense and scientific research. Functions of these polymermaterials are displayed through interactions between the materials and small molecules or ions,which include ion bonding, covalent bonding, coordinate bonding and van der Waals forces.FunCtional polymers based on the above interactions are ion exchange resins, polymer supportedreagentS, chelating …     

HYDROGEN BONDING IN POLYMERIC ADSORBENTS BASED ADSORPTION AND SEPARATION

After a concise introduction of hydrogen bonding effects in solute-solute and solute-solvent bonding,the design of polymeric adsorbents based on hydrogen bonding ,selectivity in adsorption through hydrogen bonding,and characterization of hydrogen bonding in adsorption and separation were reviewed with 28 references.     

Hydrogen bonding nature between calix[6]arene and piperidine/triethylamine

We investigated the binding nature of the 1,2,3-alternate calix[6]arene with one piperidine, two piperidines, and two triethyl amines with a special emphasis on the hydrogen bonding networks by density functional theory calculations. The 1,2,3-alternate calix[6]arene strongly binds with piperidines and triethylamines at two different binding sites, exo and endo sites. In the two binding sites, the hydrogen bonding nature shows a characteristic difference. In the exo site, there formed only one hydrogen bond, while in the endo site, two hydrogen bonds except for the triethylamine. The proton transfer within the hydrogen bonding and the hydrogen bonding types, normal hydrogen bonding (NHB), short strong hydrogen bond (SSHB), and low barrier hydrogen bonding (LBHB), will be discussed in detail.     

Statistical theory for hydrogen bonding fluid system of A_aD_d type (I): The geometrical phase transition

The influence of hydrogen bonds on the physical and chemical properties of hydrogen bonding fluid system of AaDd type is investigated from two viewpoints by the principle of statistical mechanics. In detail, we proposed two new ways that can be used to obtain the equilibrium size distribution of the hydrogen bonding clusters, and derived the analytical expression of a relationship between the hydrogen bonding free energy and hydrogen bonding degree. For the nonlinear hydrogen bonding systems, it is shown that the sol-gel phase transition can take place under proper conditions, which is further proven to be a kind of geometrical phase transition rather than a thermodynamic one. Moreover, several problems associated with the geometrical phase transition and liquid-solid phase transition in nonlinear hydrogen bonding systems are discussed.     

Statistical theory for hydrogen bonding fluid system of A a D d type (I): The geometrical phase transition

The influence of hydrogen bonds on the physical and chemical properties of hydrogen bonding fluid system of A _a D _d type is investigated from two viewpoints by the principle of statistical mechanics. In detail, we proposed two new ways that can be used to obtain the equilibrium size distribution of the hydrogen bonding clusters, and derived the analytical expression of a relationship between the hydrogen bonding free energy and hydrogen bonding degree. For the nonlinear hydrogen bonding systems, it is shown that the sol-gel phase transition can take place under proper conditions, which is further proven to be a kind of geometrical phase transition rather than a thermodynamic one. Moreover, several problems associated with the geometrical phase transition and liquid-solid phase transition in nonlinear hydrogen bonding systems are discussed.     

Statistical theory for hydrogen bonding fluid system of AaDd type (I): The geometrical phase transition

The influence of hydrogen bonds on the physical and chemical properties of hydrogen bonding fluid system of A _a D _d type is investigated from two viewpoints by the principle of statistical mechanics. In detail, we proposed two new ways that can be used to obtain the equilibrium size distribution of the hydrogen bonding clusters, and derived the analytical expression of a relationship between the hydrogen bonding free energy and hydrogen bonding degree. For the nonlinear hydrogen bonding systems, it is shown that the sol-gel phase transition can take place under proper conditions, which is further proven to be a kind of geometrical phase transition rather than a thermodynamic one. Moreover, several problems associated with the geometrical phase transition and liquid-solid phase transition in nonlinear hydrogen bonding systems are discussed.     

Comparative study on the nonadditivity of methyl group in lithium bonding and hydrogen bonding

Quantum chemical calculations at the second‐order Moeller–Plesset (MP2) level with 6‐311++G(d,p) basis set have been performed on the lithium‐bonded and hydrogen‐bonded systems. The interaction energy, binding distance, bond length, and stretch frequency in these systems have been analyzed to study the nonadditivity of methyl group in the lithium bonding and hydrogen bonding. In the complexes involving with NH₃, the introduction of one methyl group into NH₃ molecule results in an increase of the strength of lithium bonding and hydrogen bonding. The insertion of two methyl groups into NH₃ molecule also leads to an increase of the hydrogen bonding strength but a decrease of the lithium bonding strength relative to that of the first methyl group. The addition of three methyl groups into NH₃ molecule causes the strongest hydrogen bonding and the weakest lithium bonding. Although the presence of methyl group has a different influence on the lithium bonding and hydrogen bonding, a negative nonadditivity of methyl group is found in both interactions. The effect of methyl group on the lithium bonding and hydrogen bonding has also been investigated with the natural bond orbital and atoms in molecule analyses. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009     

Dependence of amide vibrations on hydrogen bonding

The effect of hydrogen bonding on the amide group vibrational spectra has traditionally been rationalized by invoking a resonance model where hydrogen bonding impacts the amide functional group by stabilizing its [(-)O-C=NH (+)] structure over the [O=C-NH] structure. However, Triggs and Valentini's UV-Raman study of solvation and hydrogen bonding effects on epsilon-caprolactum, N, N-dimethylacetamide (DMA), and N-methylacetamide (NMA) ( Triggs, N. E.; Valentini, J. J. J. Phys. Chem. 1992, 96, 6922-6931) casts doubt on the validity of this model by demonstrating that, contrary to the resonance model prediction, carbonyl hydrogen bonding does not impact the AmII' frequency of DMA. In this study, we utilize density functional theory (DFT) calculations to examine the impact of hydrogen bonding on the C=O and N-H functional groups of NMA, which is typically used as a simple model of the peptide bond. Our calculations indicate that, as expected, the hydrogen bonding frequency dependence of the AmI vibration predominantly derives from the C=O group, whereas the hydrogen bonding frequency dependence of the AmII vibration primarily derives from N-H hydrogen bonding. In contrast, the hydrogen bonding dependence of the conformation-sensitive AmIII band derives equally from both C=O and N-H groups and thus, is equally responsive to hydrogen bonding at the C=O or N-H site. Our work shows that a clear understanding of the normal mode composition of the amide vibrations is crucial for an accurate interpretation of the hydrogen bonding dependence of amide vibrational frequencies.     

Hydrogen bonding effect on photocurrent generation in porphyrin-fullerene photoelectrochemical devices

A hydrogen bonding effect on photocurrent generation has been evaluated successfully in a mixed film of porphyrin and fullerene with hydrogen bonding on an ITO electrode, which exhibits efficient cathodic photocurrent generation as compared to the reference system without hydrogen bonding.