铅离子与镉离子高选择性的大环化合物：对称四甲基六元瓜环与过渡金属及重金属离子的配合作用

利用微分脉冲伏安法研究了对称四甲基六元瓜环(TMeQ[6])与过渡金属的相互作用。结果表明该主体大环化合物对Pb2+和Cd2+离子具有较好的选择性作用。伏安数据测定表明Pb2+及Cd2+离子与对称四甲基六元瓜环以nM2+/nTMeQ[6]=2配位,其配合平衡常数分别为(KPb2+=2.12×109L2·mol-2,KCa2+=2.10×109L2·mol-2)。Pb2+离子与TMeQ[6]的晶体结构进一步证实了上述实验结果。     

相溶解度法研究环糊精对奥美沙坦酯的增溶作用

研究了3种环糊精对奥美沙坦酯药物的增溶效果。建立了高效液相色谱法测定环糊精溶液中奥美沙坦酯药物含量的方法,利用相溶解度法测定了奥美沙坦酯在不同浓度的β-环糊精(β-CD)、甲基-β-环糊精(M-β-CD)、羟丙基-β-环糊精(HP-β-CD)溶液中的溶解度,并绘制了相溶解度曲线。在0~15 mmol/L环糊精浓度范围内,奥美沙坦酯的溶解度随3种环糊精浓度的增加而线性增加,相溶解度曲线呈AL型,奥美沙坦酯与3种环糊精均是1:1的比例包合;3种环糊精对奥美沙坦酯均有显著的增溶作用且羟丙基-β-环糊精的增溶效果最佳,其次为甲基-β-环糊精和β-环糊精。     

三种瓜环与药物乙酰胆碱的主客体相互作用

本文选取了三种具有不同空腔大小的瓜环:对称四甲基六元瓜环(TMeQ[6])、七元瓜环(Q[7])、八元瓜环(Q[8]),利用核磁共振技术以及质谱分析手段探究了这三种瓜环与药物分子乙酰胆碱(ACh)的相互作用。结果表明,ACh位于TMeQ[6]的端口,与空腔较小的TMeQ[6]形成端口作用,而进入了空腔相对更大的瓜环Q[7]、Q[8]的内腔,三者均以1∶1的作用比形成了主客体超分子药物包合物。     

对称四甲基六元瓜环与紫精类化合物的超分子自组装

选取3个两端被不同长度烷基取代的紫精衍生物作为客体分子,利用紫外-可见吸收光谱、核磁共振技术、等温滴定量热、基质辅助激光解吸电离飞行时间质谱以及X射线单晶衍射技术等表征手段研究其与对称四甲基六元瓜环(TMeQ[6])的超分子自组装,结果表明这三种紫精衍生物与TMeQ[6]之间具有相同的作用模式,均为客体分子两端的烷基链部分进入到TMeQ[6]的空腔内,主客体以2∶1的作用比形成类似哑铃状的超分子自组装体.     

水溶性六元瓜环衍生物与1,ω-亚烷基吡啶主客体配合物的~1H NMR及晶体结构

利用1HNMR技术以及单晶X衍射技术考察对称四甲基取代六元瓜环(TMeQ[6])与几种1,ω-亚烷基吡啶阳离子(ω=2,4,6,8,10)客体的相互作用.在这些包结配合物中,TMeQ[6]的端口效应以及空腔效应同时存在,其主客体作用模式随着客体亚烷基碳链长短不一而各不相同.对于客体1,2-二乙基吡啶(Edpy),TMeQ[6]包结Edpy的带正电荷的吡啶环部分,形成一不对称的包结配合物;对于客体1,4-二丁基吡啶(Bdpy),TMeQ[6]选择性包结Bdpy的吡啶环部分或烷基部分存在竞争作用和快速交换;而具有较长碳链的客体1,6-二己基吡啶(Hdpy)和1,8-二丁庚基吡啶(Odpy)与TMeQ[6]通过空腔的疏水作用以及外部的离子-偶极作用形成稳定的类轮烷包结配合物;客体1,10-二癸基吡啶(Ddpy)的两个吡啶环分别被两个TMeQ[6]包结形成哑铃型的包结配合物.     

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.     

对称四甲基六元瓜环与1-丁基-4,4’-联吡啶的超分子自组装

设计合成了客体分子1-丁基-4,4’-联吡啶溴化物(BV+),利用核磁共振、紫外-可见吸收光谱、热重分析及X射线单晶衍射研究其与对称四甲基六元瓜环(TMeQ[6])的超分子自组装及形成的主客体包结配合物的结构特征.结果表明,在溶液中及固体状态下,TMeQ[6]均包结BV+的烷基链部分形成1∶1包结配合物.     

对称四甲基六元瓜环与硝酸根离子自组装配合物晶体结构

以对称四甲基六元瓜环(TMeQ[6])为主体,硝酸为客体,在水溶液中自组装形成一个新的主客体包结配合物,通过X-射线单晶衍射技术测试晶体结构.结果表明,1个TMeQ[6]包结1个NO3-,硝酸根离子置于TMeQ[6]空腔,主客体间通过水分子形成氢键发生作用,配合物结构单元之间通过共用水分子连接成一维超分子链,构成硝酸根离子"通道".     

水溶性六元瓜环衍生物与1,ω-亚烷基吡啶主客体配合物的^1HNMR及晶体结构

利用^1HNMR技术以及单晶X衍射技术考察对称四甲基取代六元瓜环（TMeQ[6]）与几种1,ω-亚烷基吡啶阳离子（ω=2,4,6,8,10）客体的相互作用．在这些包结配合物中,TMeQ[6]的端口效应以及空腔效应同时存在,其主客体作用模式随着客体亚烷基碳链长短不一而各不相同．对于客体1,2-二乙基吡啶（Edpy）,TMeQ[6]包结Edpy的带正电荷的吡啶环部分,形成一不对称的包结配合物;对于客体1,4-二丁基吡啶（Bdpy）,TMeQ[6]选择性包结Bdpy的吡啶环部分或烷基部分存在竞争作用和快速交换;而具有较长碳链的客体1,6-二己基吡啶（Hdpy）和1,8-二丁庚基吡啶（Odpy）与TMeQ[6]通过空腔的疏水作用以及外部的离子-偶极作用形成稳定的类轮烷包结配合物;客体1,10-二癸基吡啶（Ddpy）的两个吡啶环分别被两个TMeQ[6]包结形成哑铃型的包结配合物．     

PAMAM树状大分子对酮基布洛芬溶解度的影响

以酮洛芬为模型药物,研究聚酰胺-胺(PAMAM)树状大分子对酮洛芬的增溶作用,并探讨其作用机理.采用紫外光谱法测定了G1.0、G1.5、G2.0、G2.5、G3.0、G3.5PAMAM在不同浓度和不同pH时对酮洛芬的增溶量.并运用计算机模拟方法对PAMAM与酮洛芬相互作用的机理进行了探讨.实验结果表明,酮洛芬的溶解度随溶液pH值变化而变化,在pH4.0～6.0范围内,PAMAM树状大分子对酮洛芬的增溶量随着PAMAM的代数、浓度和溶液pH的增加而增大.整代和半代都具有增溶作用.然而,在同一pH条件下,对于具有相同官能团数目的整代和半代,整代增溶效果要高于半代.计算机模拟结果表明PAMAM与酮洛芬主要靠静电作用力结合.增溶机理可能是酮洛芬的羧基与PAMAM的伯胺和叔胺发生静电作用.     

Solubility enhancement of kinetin through host–guest interactions with cucurbiturils

We explored the use of cucurbiturils to form inclusion complexes to overcome the solubility problems of kinetin, a plant cytokinin. Inclusion complexes between kinetin and Q[7], TMeQ[6] and HMeQ[6] in aqueous solution and in solid state were investigated by phase solubility studies, ¹H NMR and IR. The effects of pH and temperature on complex stability were also investigated. Phase solubility studies showed that kinetin solubility increased in a linear fashion as a function of Q[7] and TMeQ[6] concentrations. However, kinetin solubility increased first, then decreased as the HMeQ[6] concentration increased, and the maximum solubility of kinetin was achieved at 4.95 mM in HMeQ[6]. The solubility of kinetin as well as the stability constant of its complex with Q[7] were affected by the pH of the medium. The thermodynamic parameters of the complex formation were also determined, and it showed that the formation of the inclusion complexes between kinetin and Q[7] was enthalpy controlled, suggesting that hydrophobic and van der Waals interactions were the main driving forces. Moreover, we found that the size of the cavity of cucurbituril played an important role in the association process. The formation of inclusion complexes between Q[7], TMeQ[6] and HMeQ[6] with kinetin was confirmed by ¹H NMR, and IR spectroscopy showed the presence of inclusion complexes in solid state. Our results demonstrated that the complexation of kinetin with Q[n] could be used to improve the solubility of kinetin in aqueous solution.     

Host–guest interactions of thiabendazole with normal and modified cucurbituril: 1H NMR,phase solubility and antifungal activity studies

Guest–host inclusion complexes between thiabendazole (TBZ) and cucurbit[7]uril (Q[7]), symmetrical tetra-methylcucurbit[6]uril (TMeQ[6]) and meta-hexamethyl-substituted cucurbit[6]uril (HMeQ[6]) in aqueous solution were investigated by ¹H NMR spectroscopy and phase solubility studies. The antifungal activities of the inclusion complexes were also determined. Analysis of the ¹H NMR spectra revealed that the host Q[7] selectively binds the benzimidazole ring moiety of the guest molecule and that the thiazole ring is encapsulated into the cavities of TMeQ[6] and HMeQ[6]. Phase solubility diagrams were analysed using rigorous procedures to obtain estimates of the complex formation constants for Q[n]-TBZ complexation. The phase solubility studies showed that TBZ solubility increased as a function of Q[7], TMeQ[6] and HMeQ[6] concentrations. We found that complexation of TBZ with Q[n] increased the inhibitory effect of TBZ on the growth of Fusarium graminearum. Our results thus demonstrate that complexation of TBZ with Q[n] could be used to improve the solubility and antifungal activity of TBZ.     

Host–guest interactions of 6-benzyladenine with normal and modified cucurbituril: 1H NMR,UV absorption spectroscopy and phase solubility methods

Guest–host inclusion complexes between 6-benzyladenine (6-BA), cucurbit[7]uril (Q[7]), symmetrical tetramethylcucurbit[6]uril (TMeQ[6]) and meta-hexamethyl-substituted cucurbit[6]uril (HMeQ[6]) in aqueous solution were investigated by ¹H NMR, UV absorption spectroscopy and phase solubility studies. The ¹H NMR spectra analysis revealed that the hosts selectively bound the phenyl moiety of the guests. Absorption spectroscopic analysis defined the stability of the host–guest inclusion complexes. A host:guest ratio of 1:1 was measured quantitatively as (5.63 ± 0.26) × 10⁴, (1.94 ± 0.17) × 10³ and (2.89 ± 0.23) × 10³ mol L^? 1 for the Q[7]-6-BA, TMeQ[6]-6-BA and HMeQ[6]-6-BA systems, respectively. Phase solubility diagrams were analysed through rigorous procedures to obtain estimates of the complex formation constants for Q[n]-6-BA complexation. The formation constants were (1.29 ± 0.24) × 10⁴ L mol^? 1 for Q[7]-6-BA, (3.20 ± 0.17) × 10³ L mol^? 1 for TMeQ[6]-6-BA and (3.52 ± 1.01) × 10³ L mol^? 1 for TMeQ[6]-6-BA. Furthermore, phase solubility studies showed that 6-BA solubility increased as a function of Q[7], TMeQ[6] and HMeQ[6] concentrations. The thermodynamic parameters of the complex formation were also determined. The formation of inclusion complexes between 6-BA and Q[7] was enthalpy controlled, suggesting that hydrophobic and van der Waals interactions were the main driving forces. Our results demonstrated that the complexation of 6-BA with Q[n] could be used to improve the solubility of 6-BA.     

2D NMR研究对称四甲基六元瓜环与5,5''-二甲基-2,2''-联吡啶的相互作用

运用二维NMR实验研究了作为主体的对称四甲基取代六元瓜环(TMeQ[6])与作为客体的5,5'-二甲基-2,2'-联吡啶(bmbpy)的相互作用.2DROESY谱上主客体分子间的NOE相关峰明确地给出了主客体的结合位置和结合物的空间结构:客体的一个吡啶环进入了主体的内腔,而另一个吡啶环则位于主体的一端端口外,进入内腔的吡啶环平面位于主体的长截面上,两个吡啶环之间为顺式构象.2DEXSY谱呈现的客体两个吡啶上对应氢之间的交换峰表明:高温下两个吡啶环交替进入主体的内腔,分别结合于主体的两个端口,形成了动态的平衡.由2DEXSY的交换峰和对角线峰强度计算出了不同温度下的交换速率,并由此得到了该交换过程的活化能为104.2kJ/mol.     

2D NMR研究对称四甲基六元瓜环与5,5'-二甲基-2,2'-联吡啶的相互作用

运用二维NMR实验研究了作为主体的对称四甲基取代六元瓜环(TMeQ[6])与作为客体的5,5'-二甲基-2,2'-联吡啶(bmbpy)的相互作用. 2D ROESY谱上主客体分子间的NOE相关峰明确地给出了主客体的结合位置和结合物的空间结构: 客体的一个吡啶环进入了主体的内腔, 而另一个吡啶环则位于主体的一端端口外, 进入内腔的吡啶环平面位于主体的长截面上, 两个吡啶环之间为顺式构象. 2D EXSY谱呈现的客体两个吡啶上对应氢之间的交换峰表明: 高温下两个吡啶环交替进入主体的内腔, 分别结合于主体的两个端口, 形成了动态的平衡. 由2D EXSY的交换峰和对角线峰强度计算出了不同温度下的交换速率, 并由此得到了该交换过程的活化能为104.2 kJ/mol.     

Kinetic and thermodynamic inclusion complexes of symmetric teramethyl-substituted cucurbit[6]uril with HCl salts of N,N′-bis(pyridylmethyl)-1,6-hexanediamine

The host–guest interaction of symmetrical α,α′,δ,δ′-tetramethyl-cucurbit[6]uril (TMeQ[6]) with the hydrochloride salts of N,N′-bis(4-pyridylmethyl)-1,6-hexanediamine (P6), N,N′-bis(3-pyridyl-methyl)-1,6-hexanediamine (M6) and N,N′-bis(2-pyridylmethyl)-1,6-hexanediamine (O6) was investigated via single crystal X-ray diffraction, ¹H NMR spectroscopy, electronic absorption spectroscopy and fluorescence spectroscopy. Single crystal X-ray diffraction showed that the hexyl moiety of P6 or M6 was incorporated in the cavity of TMeQ[6], while the two pyridylmethyl moieties of O6 were incorporated in the TMeQ[6] cavity in the solid state. The ¹H NMR results in aqueous solution revealed that the TMeQ[6]-P6 and TMeQ[6]-M6 host–guest interaction systems produce a kinetic dumbbell-shaped inclusion complex at the initial stage and then an equilibrium pseudorotaxane-shaped inclusion complex as the only product after heating. However, only the pseudorotaxane-shaped inclusion complex was observed for the TMeQ[6]-O6 host–guest interaction system. Aqueous absorption spectrophotometric analysis showed that the dumbbell-shaped inclusion complexes were stable at pH 5.6, had a host–guest ratio of 2:1 and formed quantitatively at ～10¹¹ l²/mol² for the TMeQ[6]-M6 and TMeQ[6]-O6 systems. The transformation from dumbbell to pseudorotaxane-shaped inclusion complexes for the TMeQ[6]-P6 and TMeQ[6]-M6 host–guest systems yielded activation energies of 59.35 ± 1.55 and 78.7 ± 3.45 kJ/mol, respectively. The pseudorotaxane-shaped inclusion complexes were stable at pH 5.6, had a host–guest ratio of 1:1 and formed quantitatively at ～10⁷ l/mol for the TMeQ[6]-M6 and TMeQ[6]-P6 systems.     

Difference of coordination between alkali- and alkaline-earth-metal ions to a symmetrical α,α',δ,δ'-tetramethylcucurbit[6]uril

To explore differences in coordination between alkali- and alkaline-earth-metal ions and cucurbit[n]urils, a water-soluble α,α',δ,δ'-tetramethylcucurbit[6]uril (TMeQ[6]) was used to synthesize a series of complexes and their supramolecular assemblies, based on the coordination of TMeQ[6] with alkali- and alkaline-earth-metal ions. The complexes and corresponding supramolecular assemblies were structurally characterized by single-crystal X-ray diffraction. Unlike cucurbituril (Q[6]), which formed the metal-Q[6] polymers based on the direct coordination of carbonyl oxygen atoms to the alkali-metal ions, TMeQ[6] formed metal-TMeQ[6] polymers based on the direct coordination of carbonyl oxygen atoms with the alkaline-earth-metal ions rather than the alkali-metal ions.     

溶剂驱动四甲基六元瓜环桥联聚丙烯酸的苯酚派生物对杀菌剂的吸附和解析

根据苏氏一锅法,在过硫酸铵既作为氧化剂又作为引发剂的条件下合成了一系列四甲基六元瓜环桥联聚丙烯酸.研究了丙烯酸浓度、四甲基六元瓜环投入量和过硫酸铵浓度对聚合物形成的影响.四甲基六元瓜环桥联聚丙烯酸可以进一步与苯酚发生酯化反应,生成不溶于水的派生物,因此可用于吸附和解析杀菌剂.     

对称四甲基六元瓜环与2-氨基甲基吡啶相互作用的研究

分别用核磁共振、紫外可见吸收和X射线单晶衍射方法研究对称四甲基六元瓜环与2-氨基甲基吡啶的相互作用及其结构特征. ¹H NMR谱图和紫外可见吸收光谱图清晰表明, 2-氨基甲基吡啶与对称四甲基六元瓜环有明显的相互作用, 客体2-氨基甲基吡啶的吡啶环部分进入了瓜环空腔, ¹H NMR谱图相关质子峰的积分强度以及客体吸光度随主体瓜环浓度变化明确表示它们之间形成了1∶1的包结配合物, 此包结比并不随瓜环的浓度增加而改变. X射线单晶衍射法对包结配合物晶体的测定进一步证实了核磁共振、紫外可见吸收方法所得结论.