八元瓜环与抗癌药物甲氨蝶呤的超分子相互作用

利用紫外吸收光谱法考察了八元瓜环(Q[8])与抗癌药物甲氨蝶呤(MTX)的相互作用;同时研究了甲氨蝶呤的不同质子化形式及体系温度对相互作用的影响;计算了相应的稳定常数及热力学参数等.实验结果表明,Q[8]与MTX作用比为1∶1,包结平衡常数为(7.64±1.52)×104 L/mol;龄前热力学参数测定结果表明,上述主...     

三种六元瓜环与Sr(Ⅱ)离子的配位及超分子自组装

本文以六元瓜环及两种部分甲基取代六元瓜环(统称为Q[6]s)为构筑元件,合成了4个Q[6]s-Sr髤离子的配合物,用X射线单晶衍射方法测定了配合物的晶体结构。结果表明,Q[6]s-Sr髤离子配合物自组装形成不同结构的分子链,体系中存在Cl-离子时,Q[6]s-Sr髤离子形成配位聚合链,而只有NO3-离子存在时,形成水分子配位桥连的超分子链。     

瓜环的超分子化学研究进展

总结了瓜环化学在分子组装、分子器件、生物化学、药物化学等方面的最新进展.同时,也展现了我们在瓜环化学方面进行的初步的研究.     

三种六元瓜环与Sr(Ⅱ)离子的配位及超分子自组装

本文以六元瓜环及两种部分甲基取代六元瓜环(统称为Q[6]s)为构筑元件,合成了4个Q[6]s-Sr(Ⅱ)离子的配合物,用X射线单晶衍射方法测定了配合物的晶体结构。结果表明,Q[6]s-Sr(Ⅱ)离子配合物自组装形成不同结构的分子链,体系中存在Cl-离子时,Q[6]s-Sr(Ⅱ)离子形成配位聚合链,而只有NO3-离子存在时,形成水分子配位桥连的超分子链。     

八元瓜环与1,7-二(2-苯并咪唑)-庚烷的超分子自组装

以氯化1,7-二（2-苯并咪唑）-庚烷（SBHt）为客体,八元瓜环（Q[8]）为主体,利用¹H NMR技术、动态光散射实验、荧光发射光谱、紫外吸收光谱详细探索了其在溶液中的相互作用、超分子自组装过程及作用模式. 首先考察了八元瓜环对客体pKa的影响,确定了研究主客体相互作用的条件,并详细探索了主客体的超分子自组装过程及作用模式. 主体Q[8]与客体SBHt相互作用的¹H NMR谱图表明,主客体相互作用自组装形成1：1超分子聚合物. 这一推断得到动态光散射实验、紫外吸收光谱、荧光发射光谱测定结果的证实,并通过紫外吸收光谱、荧光发射光谱确定其表观稳定常数分别为2.79×10⁵ L/mol及2.48×10⁵ L/mol. 而晶体结构测定表明主体Q[8]与客体SBHt自组装形成1：2的简单包结配合物. 导致Q[8]与SBHt在溶液中和固体状态下形成不同自组装结构可能源于瓜环的外壁作用与包结作用竞争所致.     

五元瓜环与钕离子在四氯酸锌离子诱导下构筑的配合超分子自组装

在四氯酸锌离子诱导下,五元瓜环能与钕离子构筑形成二维配合超分子自组装。在HCl介质中,Zn2+容易形成四氯酸锌离子,在其诱导作用下,钕离子和五元瓜环端口羰基氧直接配位形成二维超分子自组装体。结果表明锌离子作为一种结构导向剂在形成瓜环基超分子自组装体中起到重要作用。     

五元瓜环与钕离子在四氯酸锌离子诱导下构筑的配合超分子自组装

在四氯酸锌离子诱导下,五元瓜环能与钕离子构筑形成二维配合超分子自组装。在HCl介质中,Zn²⁺容易形成四氯酸锌离子,在其诱导作用下,钕离子和五元瓜环端口羰基氧直接配位形成二维超分子自组装体。结果表明锌离子作为一种结构导向剂在形成瓜环基超分子自组装体中起到重要作用。     

2,7-萘二磺酸阴离子导向五元瓜环基超分子自组装体的制备及其荧光检测性能

通过引入2,7-萘二磺酸(2,7-NDA^2-)阴离子作为结构导向剂,与五元瓜环(Q[5])和过渡金属离子(Co²⁺、Ni²⁺、Zn²⁺、Cd²⁺)在水热条件下制备了4种新颖的Q[5]基超分子自组装体(Q[5]-SA),即{[M(H₂O)4(Q[5])]·(NDA)}·x H₂O(M=Co (1)、Ni (2)、Zn (3))和{[Cd2Cl2(H₂O)4(Q[5])]·(NDA)}·13H₂O (4)。单晶X射线衍射测试结果表明,自组装体1～3同构,其中Q[5]仅一端的部分端口羰基氧原子与金属离子配位形成简单配合物;而4中Q[5]的2个端口均与金属离子Cd²⁺配位形成了一维配位链。在自组装体1～4中,配体2,7-H2NDA均全脱质子,形成2,7-NDA2-阴离子平衡体系电荷,但均未能与金属离子配位,而在2,7-NDA2-阴离子与Q[5]外壁之间的瓜环外壁作用下进一步形成...     

2,7-萘二磺酸阴离子导向五元瓜环基超分子自组装体的制备及其荧光检测性能

通过引入2,7-萘二磺酸(2,7-NDA^2-)阴离子作为结构导向剂,与五元瓜环(Q[5])和过渡金属离子(Co²⁺、Ni²⁺、Zn²⁺、Cd²⁺)在水热条件下制备了4种新颖的Q[5]基超分子自组装体(Q[5]-SA),即{[M (H₂O)₄(Q[5])]·(NDA)}·xH₂O (M=Co (1)、Ni (2)、Zn (3))和{[Cd₂Cl₂(H₂O)₄(Q[5])]·(NDA)}·13H₂O (4)。单晶X射线衍射测试结果表明,自组装体1~3同构,其中Q[5]仅一端的部分端口羰基氧原子与金属离子配位形成简单配合物;而4中Q[5]的2个端口均与金属离子Cd²⁺配位形成了一维配位链。在自组装体1~4中,配体2,7-H₂NDA均全脱质子,形成2,7-NDA^2-阴离子平衡体系电荷,但均未能与金属离子配位,而在2,7-NDA^2-阴离子与Q[5]外壁之间的瓜环外壁作用下进一步形成三维超分子结构。此外,还研究了自组装体1和4的荧光传感性能,结果表明它们都能够作为抗生素诺氟沙星(NFX)的比率型荧光探针。     

紫精类化合物分子聚集体材料的界面组装

紫精类化合物具有良好的电化学活性,并且在发生氧化还原反应时伴有颜色的变化,在膜修饰电极、电致变色材料和分子器件的研制等方面受到广泛的关注。紫精中的烷基链非常易于进行化学修饰,因而比较适合于通过自下而上的分子自组装技术制备多功能的分子和纳米材料。本文综述了利用Langmuir-Blodgett法、自组装法和层层组装法制备紫精分子聚集体材料的研究进展,并讨论了分子聚集体薄膜中紫精的结构、电致变色、电化学氧化还原特性及其在研制超分子器件方面的应用。     

七元瓜环与N,N’-二甲基-苯甲基-1,10-二氨基癸烷的超分子自组装

设计合成了具有多个作用位点的长链分子N,N’-二甲基-苯甲基-1,10二氨基癸烷(C10DA)并将其作为客体,利用1H NMR、紫外吸收光谱及荧光光谱等手段考察了C10DA与七元瓜环(主体)的相互作用,以及形成的主客体包结配合物的结构特征.结果表明,随着主客体摩尔比的变化,其作用模式从类轮烷型包结配合物转变成哑铃型包结配合物,这一特性在分子器件的制备方面具有潜在的应用前景.     

六元瓜环、对称四甲基六元瓜环与2,2'-(1,8-辛烷)-二异喹啉二溴化物的自组装模式

利用核磁共振波谱、 紫外吸收光谱、 荧光光谱和单晶X射线衍射分析等考察了六元瓜环(Q[6])及对称四甲基六元瓜环(TMeQ[6])与2,2'-(1,8-辛烷)-二异喹啉二溴化物的相互作用. 实验结果表明, 客体分子分别与这2种瓜环自组装形成相似的1∶1包结配合物, 但晶体结构分析结果表明两个体系在主客体分子间作用力诱导下形成了不同的空间堆积模式, 其包结常数分别为K_K8-Q[6]=4.18×10⁷ L/mol, K_K8-TMeQ[6]=6.11×10⁷ L/mol.     

H3BTC‐Induced Supramolecular Assembly Based on Cucurbit[6]uril: Possible Application for Sensing Small Molecules

The compound 2[Ca(H₂O)₃ (DMF@CB[6])] · 2(BTC) · 15H₂O ( CCUT ‐ 102 , CB[6] = cucurbit[6]uril; H₃BTC = 1,3,5‐benzenetricarboxylic acid) was synthesized using the approach of organic guest‐induced formation of polymers or frameworks based on the coordination of metal ions and cucurbit[n]urils. The compound was characterized by X‐ray diffraction analysis, PXRD, IR spectroscopy, thermogravimetric and elemental analyses. According to the X‐ray diffraction data, the calcium atom is coordinated by the oxygen atoms of the CB[6] molecule, water molecules, and N ,N‐dimethylformamide (DMF). The internal cavity of CB[6] is occupied by DMF. Each H₃BTC molecule interacts the CB[6] molecules through π?π interactions between aromatic rings of H₃BTC and the rings of CB[6]. The luminescence behaviors and sensing properties of CCUT ‐ 102 in different solvents were also studied.     

Cucurbit[8]uril (CB[8])‐Based Supramolecular Switches

The use of cucurbit[8]uril as a molecular host has emerged in the chemical literature as a reliable strategy for the creation of dynamic chemical systems, owing to its ability to form homo‐ and heteroternary complexes in aqueous media with appropriate molecular switches as guests. In this manner, CB[8]‐based supramolecular switches can be designed in a predictable and modular fashion, through the selection of appropriate guests able to condition the redox, photochemical, or pH‐triggered behavior of tailored multicomponent systems. Furthermore, CB[8] allows the implementation of dual/triple and linear/orthogonal stimuli‐dependent properties into these molecular devices by a careful selection of the guests. This versatility in their design gives these supramolecular switches great potential for the rational development of new materials, in which their function is not only determined by the custom‐made stimuli‐responsiveness, but also by the transient aggregation/disaggregation of homo‐ or heteromeric building blocks.     

A cucurbit[8]uril recognized rigid supramolecular polymer with photo-stimulated responsiveness

A rigid supramolecular polymer was constructed in aqueous solution via cucurbit[8]uril(CB[8]) host recognition with a rigid monomer containing an azobenzene unit and two 4,4'-bipyridin-1-ium(BP)moieties in the two ends, which also exhibited photo-responsiveness owing to the photoinduced trans–cis isomerization of azobenzene group.     

Cucurbit[7]uril as a Supramolecular Artificial Enzyme for Diels–Alder Reactions

The ability to mimic the activity of natural enzymes using supramolecular constructs (artificial enzymes) is a vibrant scientific research field. Herein, we demonstrate that cucurbit[7]uril (CB[7]) can catalyse Diels–Alder reactions for a number of substituted and unreactive N ‐allyl‐2‐furfurylamines under biomimetic conditions, without the need for protecting groups, yielding powerful synthons in previously unreported mild conditions. CB[7] rearranges the substrate in a highly reactive conformation and shields it from the aqueous environment, thereby mimicking the mode of action of a natural Diels–Alderase. These findings can be directly applied to the phenomenon of product inhibition observed in natural Diels–Alderase enzymes, and pave the way toward the development of novel, supramolecular‐based green catalysts.     

Supramolecular Crystal Networks Constructed from Cucurbit[8]uril with Two Naphthyl Groups

Naphthyl groups are widely used as building blocks for the self-assembly of supramolecular crystal networks. Host–guest complexation of cucurbit[8]uril (Q[8]) with two guests NapA and Nap1 in both aqueous solution and solid state has been fully investigated. Experimental data indicated that double guests resided within the cavity of Q[8], generating highly stable homoternary complexes NapA₂@Q[8] and Nap1₂@Q[8]. Meanwhile, the strong hydrogen-bonding and π···π interaction play critical roles in the formation of 1D supramolecular chain, as well as 2D and 3D networks in solid state.     

八元瓜环对氯化矢车菊素溶解性、稳定性及抗氧化性的影响

采用核磁共振氢谱(¹H NMR)、 红外光谱及紫外吸收光谱等方法考察了八元瓜环(Q[8])对氯化矢车菊素(Cy)的包结作用. 结果表明, 在pH=0.8的盐酸介质中, Q[8]可与Cy形成摩尔比为1:1的主客体配合物, 紫外吸收光谱法测得的主-客体结合常数为1.51×10⁶ . 相溶解度研究结果表明, Q[8]能使饱和Cy溶液的溶解度增大, 当Q[8]浓度为100 μmol/L时, 可使Cy的溶解度增大12.21倍. 紫外吸收光谱随时间变化结果表明, 在较为稳定存在形态及相同实验条件下, Q[8]/Cy溶液比Cy溶液的稳定性提高了2.58倍. 抗氧化性实验结果表明, Q[8]/Cy包合物和Cy均表现出较好的抗氧化活性.     

Study on the Interaction and Properties of Cucurbit[8]uril with Oroxin B

The interaction between cucurbit[8]uril(Q[8]) and oroxin B(ORB) was investigated by UV-visible(UV-Vis) spectroscopy, isothermal titration calorimetry(ITC), mass spectrum(MS) and nuclear magnetic resonance(NMR) spectroscopy. The results showed that ORB formed a 2:1 inclusion complex with Q[8] with a binding constant of 8.266×10⁵ L²·mol^-2. ORB had good scavenging ability for 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate)(ABTS) free radicals(IC₅₀=5.74 μmol/L) and the addition of Q[8] did not significantly affect the antioxidant activity of ORB(IC₅₀=5.76 μmol/L). A phase solubility experiment revealed a 1.86-fold increase in the solubility of ORB when c(Q[8])=100 μmol/L. In vitro drug release experiments showed that the release rate for ORB@Q[8] complex was lower than that of ORB in artificial intestinal juice, and higher than that of ORB in artificial gastric juice.