金属卟啉配合物的分子识别研究进展

综述了金属卟啉配合物的分子识别研究进展。介绍了金属卟啉配合物在分子形状与大小识别、官能团识别和手性识别方面的研究概况。     

金属卟啉配合物的分别识别研究进展

综述了金属卟啉配合物分子识别研究进展，介绍了金属卟啉配合在物分子形状与大小识别、管能团识别和手性识别方面的研究概况。     

金属卟啉对杂环及DNA分子识别研究进展

介绍了近几年国内外关于组装金属卟啉对杂环分子、DNA碱基以及RNA的分子识别的研究进展, 并简述了本课题组对金属卟啉与杂环及药物分子复合物的理论研究工作. 金属卟啉广泛存在于自然界和生物体中, 此识别过程对研究和模拟生命体中各种细胞之间的相互作用具有重要意义. 组装后的金属卟啉可通过轴向配位、氢键及π-π堆积作用等识别杂环分子. 金属卟啉对DNA的识别主要有四种作用方式, 而金属卟啉对DNA以及RNA分子的识别主要靠疏水作用力、静电力以及自堆叠作用. 卟啉阳离子与DNA的结合位点受主体侧链取代基的空间结构影响. 金属卟啉对药物分子的识别靠配位键和氢键进行, 以配位键结合的复合物通常具有更高的结合能.     

钴卟啉对有机小分子的手性识别

采用含时密度泛函理论方法研究了手性钴卟啉识别手性生物小分子, 解释了分子结构与光学活性的关系. 通过基组叠加误差(BSSE)校正, Co(III)-卟啉衍生物与(S)-脯氨醇和(S)-2-丁氨之间的作用能分别为310.5和241.6 kJ/mol. 这种较强的分子识别作用起源于主体与客体之间的配位和氢键作用. 具有较大负比旋度的金属卟啉分子对具有较小的正比旋度的生物分子的分子识别作用, 极大地抵消了金属卟啉分子的负比旋度数值. 电子吸收光谱和电子圆二色谱表明, 最低能带起源于主体卟啉环-客体小分子的HOMO-LUMO电荷转移跃迁, 具有负或正的康登效应. 较高能带由配体内部的π→π*电子跃迁所致, 具有一个负的和一个正的康登效应. 最高能带由取代基到卟啉环的p→π*电子跃迁所致, 具有两个负的康登效应.     

手性金属卟啉配合物的性能研究

本文综述了近几年来手性金属卟啉配合物在主客体化学、立体催化及光电化学领域的性能研究成果。分析了在主客体化学中手性卟啉作为分子识别反应主体所具有的结构特征;介绍了模拟生物大分子的功能时手性卟啉所反映出的识别机制;评述了手性卟啉对苯乙烯及其衍生物的环丙烷化、羟基化及氨化等催化反应中所展示出的对映选择性和催化稳定性;概括了手性卟啉配合物在模拟植物光合成反应和制作新型光学材料方面所具有的光电性能。最后总结了手性卟啉研究成果的应用范围,并展望了手性卟啉在催化氧化方面的研究和发展方向。     

多羟基卟啉化合物的合成及其分子识别研究

分子识别在生命活动中起着重要作用.由于金属卟啉及其配合物作为主体分子有其独特的优点,如卟啉环具有刚性结构,周边功能团的方向和位置可以较好地得到控制,使之与客体分子之间有最佳的相互作用;其次,卟啉分子有较大的表面,对金属卟啉分子轴向配体周围的空间容积和相互作用方向的控制余地较大;此外,金属卟啉及其配合物具有多样性.     

含联萘基元的刚性环状齐聚物手性孔穴的振动圆二色谱研究

纳米尺度刚性环状齐聚物因其具有独特的孔穴结构,在基础与应用研究中引起了人们的广泛关注.当具有功能基团的分子骨架形成环状结构时,这种功能分子孔穴在分子识别及主-客体化学等方面具有广阔的应用前景.含有手性基团的手性大环分子具有特定的手性孔穴,在手性拆分、手性识别等方面引起了各国研究者的兴趣.     

基于手性大环主体的对映选择性识别

手性均一性是生命体系的基本物质结构特征,这导致手性对映体分子的识别和区分在许多与生命健康相关的领域都具有重要意义.大环主体是进行分子识别的重要工具,而通过构筑手性大环主体来实现对手性对映体客体的识别和区分一直是超分子化学研究的重要课题.近年来,随着大环主客体化学的蓬勃发展,基于手性大环主体的对映选择性识别也取得长足进步.本文概述了手性大环的常用构筑策略,并重点综述了具有代表性的手性大环主体以及它们的对映选择性识别能力,旨在激发具有优异对映选择性识别和区分能力的大环主体的开发和应用.最后总结了这一领域目前存在的挑战和发展前景.     

5-(2-羧基苯基)-10,15,20-三苯基卟啉对氨基酸酯的分子识别模型研究

对氨基酸及其衍生物的分子识别一直是仿生化学领域中的重要课题.以金属卟啉配合物作为主体分子对氨基酸酯的分子识别是最近几年来的热点之一^[15].氨基酸是蛋白质的主要组成部分,在蛋白质合成过程中,对氨基酸及其衍生物的识别是关健的一步.     

液相色谱手性拆分机理的热力学方法研究

手性识别是分子识别的一个重要组成部分.液相色谱手性拆分机理研究有助于色谱条件的优化和新型手性固定相的设计,也有助于理解手性识别机制.本文就线性色谱与非线性色谱条件下手性拆分过程对应热力学参数的推求方法进行了评述,阐述了相关热力学参数的涵义及其在色谱保留及手性拆分机理探讨中的应用,并展望了该领域的研究前景.     

光学活性金属卟啉的磁手性效应研究

磁光学活性与自然光学活性均可用介质对左右圆偏振光的吸收之差来表示 .但自然光学活性和磁光学活性的物理机制是截然不同的 ,前者源于镜象不能互相重叠介质的非定域光学响应 ( nonlocaloptical response) ,而后者则是由于介质的时间反演对称性 ( time- reversal symmetry)被磁场打破所致 .理论分析表明 ,当介质的两种光学活性同时存在时 ,将会出现一个新的附加光学效应 ,这种磁光学活性与自然光学活性之间的交叉效应称为磁手性效应 ( magneto- chiral effect)或磁手二色性 ( magneto-chiral dichroism) [1,2 ] .磁手性效应通常很弱 ,直到 1…     

用于手性识别α-氨基酸的方酰胺荧光探针分子

以天然氨基酸为手性原料合成了4种新型的手性方酰胺荧光探针分子(5~8), 该合成路线简短, 后处理简单, 无需柱层析纯化. 以荧光光谱为检测手段, 测试了此类探针分子对苯丙氨酸、 缬氨酸和脯氨酸的手性识别效果, 结果表明, 探针分子5可以有效识别苯丙氨酸的2个对映异构体. 当加入L-苯丙氨酸后, 探针分子5的荧光强度显著增强, 而加入D-苯丙氨酸后探针分子5的荧光强度显著减弱, 2种异构体的荧光强度比(I_L/I_D)可达2.4.     

Efficient complexation of pyrrole-bridged dizinc(II) bisporphyrin with fluorescent probe pyrene: synthesis, structure, and photoinduced singlet-singlet energy transfer

A diethylpyrrole‐bridged dizinc(II) bisporphyrin (Zn₂DEP) is reported that encapsulates fluorescent probe pyrene molecules through strong π–π interactions, which can relay information about the chemical environment in the interior of the host–guest supramolecular assembly. X‐ray structures of both Zn₂DEP and the encapsulated pyrene complex are reported, which provides a rare opportunity to investigate the structural changes upon guest binding. A comparative structural analysis demonstrated the exceptional ability of this bisporphyrin platform to open its binding pocket for pyrene encapsulation by a vertical displacement of more than 2.45 Å, although both Zn₂DEP and the pyrene complex have nearly parallel porphyrin ring orientations. The ¹H NMR spectrum of the encapsulated pyrene complex in solution shows the upfield shifts of the pyrene protons due to a strong ring current effect, which demonstrates the retention of the solid‐state structure in solution. To further assess the extent to which pyrene guests remain encapsulated in solution, a known fluorescence quencher, dimethylaniline, was added to the host–guest assembly, which shows no exciplex formation for days in nonpolar solvents. Thus, the assembly also retained the structural integrity in solution for a long time. The association constant (K_asso) for such a complexation process in solution was observed to be 1.78×10⁵ M ^?2 for 1:2 binding. Steady‐state fluorescence and lifetime studies indicate significant photoinduced singlet–singlet energy transformation from the excited state of pyrene to zinc bisporphyrin.     

Induction of supramolecular chirality in di-zinc(II) bisporphyrin via tweezer formation: synthesis, structure and rationalization of chirality

Two new supramolecular complexes consisting of an achiral bisporphyrin host and a chiral diamine guest are reported. One shows a remarkably high amplitude bisignate CD signal while the other one shows a very low value. X-ray structure and other spectroscopic investigations of the tweezer complexes clearly rationalize the origin of the optical activity that has so far remained an unresolved issue.     

醇存在下R,S-1,1′-2-联萘酚对映体的环糊精手性识别研究

以R,S-1,1′-2-联萘酚对映体为手性客体分子, 采用荧光探针法详细研究了各种醇对β-环糊精/(R或S)-1,1′-2-联萘酚对映体的手性包络和手性荧光猝灭等性质的影响, 结果表明, 醇的存在可显著影响R,S-1,1′-2-联萘酚对映体与β-环糊精形成包络物的包络形式和包络常数. 通过与该对映体的β-环糊精手性固定相高效液相色谱拆分法比较研究结果表明, 醇等第三客体分子可显著影响环糊精对对映体化合物的手性选择性和分离度.     

Acetylation of beta-cyclodextrin surface-functionalized cellulose dialysis membranes with enhanced chiral separation

The enhanced enantiomeric separation of racemic phenylalanine solution has been demonstrated by the membrane-based chiral resolution method using an acetylated beta-cyclodextrin-immobilized cellulose dialysis membrane. Beta-cyclodextrin (CD) was first immobilized onto the surface of commercial cellulose dialysis membranes, followed by the acetylation reaction through the treatment of the membranes with acetic anhydride to form the chiral selective acetylated beta-cyclodextrin-immobilized cellulose dialysis membrane. The acetylated CD-immobilized membrane exhibits enantioselectivity in the range of 1.26-1.33 depending on the acetylation time. The improvement in enantioselectivity after acetylation was mainly attributed to the better discrimination ability of acetylated CD and the decrease in membrane pore size. Molecular modeling simulations indicate that the acetylation of hydroxyl groups would result in a CD conformation with torus distortions and would create higher steric hindrance for penetrants. As a result, compared to the original CD, the acetylated CD may have less effective binding but better discrimination of enantiomers. The energy drop is only 3 kcal/mol between different enantiomers before and after the binding of phenylalanine with an unmodified CD. The energy drop increases to 10 kcal/mol if acetylated CD is employed as the chiral selector, showing stronger characteristics for chiral selection.     

氨基酸桥联手性双卟啉的二阶非线性光学性质研究

采用半经验量子化学PM3方法对系列氨基酸桥联双卟啉1, 2, 3, 4及其锌配合物进行了几何结构优化, 并用TDHF/PM3方法计算了其静态二阶非线性光学系数. 计算结果表明, L型-氨基酸桥联双卟啉及其锌配合物具有右手螺旋结构特征. 在电偶极近似下, 不同手性氨基酸侧链基团R对分子的总体二阶非线性光学系数β和βHRS的影响不大, 但对二阶非线性光学系数的手性分量βxyz却有显著影响. βxyz与螺旋结构参数r2ζ/L4成正比关系, 符合手性分子二阶非线性光学响应的单电子螺旋模型理论. β张量分析表明, 此类分子表现为以八极为主、 偶极为辅的多极分子, 卟啉环与锌离子的配位有利于增加二阶非线性光学响应的偶极分量和手性分量βxyz.     

A Chiral Molecular Cage Comprising Diethynylallenes and N-Heterotriangulenes for Enantioselective Recognition

Chirality, a characteristic tool of molecular recognition in nature, is often a complement of redox active systems. Scientists, in their eagerness to mimic such sophistication, have designed numerous chiral systems based on molecular entities with cavities, such as macrocycles and cages. In an attempt to combine chirality and redox-active species, in this contribution we report the synthesis and detailed characterization of a chiral shape-persistent molecular cage based on the combination of enantiopure diethynylallenes and electron-rich bridged triarylamines, also known as N-heterotriangulenes. Its ability for chiral recognition in solution was revealed through UV/vis titrations with enantiopure helicenes.     

Influence of the solvent and metal center on supramolecular chirality induction with bisporphyrin tweezer receptors. Strong metal modulation of effective molarity values

We describe the synthesis of a bisporphyrin tweezer receptor 1·H(4) and its metalation with Zn(II) and Rh(III) cations. We report the thermodynamic characterization of the supramolecular chirality induction process that takes place when the metalated bisporphyrin receptors coordinate to enantiopure 1,2-diaminocyclohexane in two different solvents, toluene and dichloromethane. We also performed a thorough study of several simpler systems that were used as models for the thermodynamic characterization of the more complex bisporphyrin systems. The initial complexation of the chiral diamine with the bisporphyrins produces a 1:1 sandwich complex that opens up to yield a simple 1:2 complex in the presence of excess diamine. The CD spectra associated with the 1:1 and 1:2 complexes of both metalloporphyrins, 1·Zn(2) and 1·Rh(2), display bisignate Cotton effects when the chirogenesis process is studied in toluene solutions. On the contrary, in dichloromethane solutions, only 1·Zn(2) yields CD-active 1:1 and 1:2 complexes, while the 1:2 complex of 1·Rh(2) is CD-silent. In both solvents, porphyrin 1·Zn(2) features a stoichiometrically controlled chirality inversion process, which is the sign of the Cotton effect of the 1:1 complex is opposite to that of the 1:2 complex. In contrast, porphyrin 1·Rh(2) affords 1:1 and 1:2 complexes in toluene solutions with the same sign for their CD couplets. Interestingly, in both solvents, the signs of the CD couplets associated with the 1:1 sandwich complexes of 1·Zn(2) and 1·Rh(2) are opposite. The amplitudes of the CD couplets are higher for 1·Zn(2) than for 1·Rh(2). This observation is in agreement with 1·Rh(2) having a smaller extinction coefficient than 1·Zn(2). We performed DFT-based calculations and assigned molecular structures to the 1:1 and 1:2 complexes that explain the observed signs for their CD couplets. Unexpectedly, the quantification of the thermodynamic stability of the two metallobisporphyrin/diamine 1:1 sandwich complexes revealed the existence of interplay between effective molarity values (EM) and the strength of the intermolecular interaction (K(m); N···Zn or N···Rh) used in their assembly. The EM for the N···Rh(III) intramolecular interaction is 3 orders of magnitude smaller than that for the N···Zn(II) interaction, both of which are embedded in the same scaffold of the 1·M(2) bisporphyrin receptor.     

手性锌卟啉与氨基酸酯的分子识别性能

通过紫外-可见光谱滴定法, 研究了手性锌卟啉配合物[p-(L-Leu)C2O-TPPZn]与手性氨基酸酯客体在CHCl3中的分子识别行为. 实验结果表明, D型氨基酸酯的缔合常数比L型的大, 且缔合常数按K(AlaOCH3)相似文献