七、八元瓜环对萘二胺异构体相互作用的考察

利用紫外吸收光谱、荧光光谱以及¹H NMR方法考察了七、八元瓜环(Q7], Q8])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: Q7]与客体g1发生端口作用, 作用比为1∶1; Q7]与客体g2, g3相互作用也形成1∶1的包结配合物. Q8]与三种客体相互作用情况各不相同, 除Q8]与客体g2相互作用形成1∶2的包结配合物; Q8]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Q7]主客体体系, pH大于6.0; Q8]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. Q7], Q8]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Q8]形成的包结配合物被1,10-癸二胺盐酸盐部分取代.

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

The interaction between cucurbitn]uril (n＝7 or 8) (Q7], Q8]) and diaminonaphthalene 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 Q7] in a ratio of 1∶1 while a portal interaction of the isomer g1 with Q7] in a ratio of 1∶1 was observed. Interaction ratios of Q8] with the three guest compounds were different: Q8] bind g2 to form an inclusion complex in a ratio of 1∶2, and Q8] bind g1 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 Q7] with g1, g2 or g3 were decomposed completely at pH＞6.0, and the inclusion complexes of Q8] with g1, g2 or g3 were decomposed completely at pH＞12.0. Competitive experiments showed that the guests g1, g2 and g3 bound by Q7] can be substituted by competitive guest 1-amineadmantane•HCl, and the guests g1 and g3 bound by Q8] can be substituted by competitive guest 1,10-diaminodecane•2HCl completely, however, only part of g3 bound by Q8] can be substituted by competitive guest 1,10-diaminodecane•2HCl.