七、八元瓜环对萘二胺异构体相互作用的考察

Interaction between Cucurbit(n)uril (n=7 or 8) and Diaminonaphthalene Isomers

利用紫外吸收光谱、荧光光谱以及1HNMR方法考察了七、八元瓜环(Q[7],Q[8])与1,8-萘二胺(g1),2,3-萘二胺(g2),1,5-萘二胺(g3)的相互作用.实验结果表明:Q[7]与客体g1发生端口作用,作用比为1∶1;Q[7]与客体g2,g3相互作用也形成1∶1的包结配合物.Q[8]与三种客体相互作用情况各不相同,除Q[8]与客体g2相互作用形成1∶2的包结配合物;Q[8]与客体g1或g3可发生相互作用,形成溶解性较差的作用产物,其表观相互作用的比例为1∶1.考察溶液酸度对主客体相互作用的影响还表明:当pH大于某一值之后,如Q[7]主客体体系,pH大于6.0;Q[8]主客体体系,pH大于12.0,用光谱方法观察不到瓜环与客体的相互作用.Q[7],Q[8]为主体的上述主客体作用产物分别与金刚烷胺盐酸盐、1,10-癸二胺盐酸盐的竞争反应结果表明,已作用的萘二胺异构体容易被所选用的竞争客体所取代,只有g2与Q[8]形成的包结配合物被1,10-癸二胺盐酸盐部分取代.

The interaction between cucurbit[n]uril （n=7 or 8） （Q[7], Q[8]） and diarninonaphthalene isomers, such as 1,8-diaminonaphthalene （g1）, 2,3-diaminonaphthalene （g2）, 1,5-diaminonaphthalene （g3） was studied by UV spectroscopy, fluorescence spectrophotometry and ^1H NMR technique. The experimental results revealed that the diaminonaphthalene isomers g2 and g3 as molecular guests were bound in the cavity of Q[7] in a ratio of 1 ： 1 while a portal interaction of the isomer gl with Q[7] in a ratio of 1 ： 1 was ob- served. Interaction ratios of Q[8] with the three guest compounds were different： Q[8] bind g2 to form an inclusion complex in a ratio of 1 ： 2, and Q[8] bind gl or g3 to form a less soluble host-guest product in a ratio of 1 ; 1. The results also showed that the stability of the inclusion complexes was related to the pH of solution： the inclusion complexes of Q[7] with gl, g2 or g3 were decomposed completely at pH〉6.0, and the inclusion complexes of Q[8] with gl, g2 or g3 were decomposed completely at pH〉 12.0. Competitive experiments showed that the guests gl, g2 and g3 bound by Q[7] can be substituted by competitive guest 1-amineadmantaneo·HCl, and the guests gl and g3 bound by Q[8] can be substituted by competitive guest 1,10-diaminodecane-2HCl completely, however, only part of g3 bound by Q[8] can be substituted by competitive guest 1,10-diaminodecane·2HCl.