光谱分析法研究瓜环对苯并咪唑衍生物的分子识别

Recognition of cucurbit [n=6～8] urils toward benzimidazole derivatives with spectroscopy

利用紫外吸收光谱法、荧光光谱法测定了三种苯并咪唑衍生物与六、七、八元瓜环的相互作用,计算出了主客体配合物的稳定常数,并考察了酸度对苯并咪唑衍生物与瓜环相互作用的影响,最后用紫外吸收光谱法测定了瓜环对三种客体化合物的回收率。实验结果表明:在一定的pH范围内,用紫外吸收光谱法、荧光光谱法可以很明显的观察到瓜环与三种客体的相互作用。六元瓜环与客体相互作用形成1∶1的包结配合物,七、八元瓜环与客体相互作用分别形成1.5∶1和1∶2的包结配合物,六、八元瓜环与三种客体相互作用形成的主客体配合物的稳定常数分别在103～104L·mol-1和1011～1012L2·mol-2范围内。瓜环对三种客体的回收率在98%～105%之间。

The authors investigated interaction of Cucurbit[ n = 6 -8 ] urils with three Benzimidazole derivatives, influences of pH on the interaction of the hosts with the guests and calculations of the stability constants by using UV spectroscopy and fluorescence spectrophotometry. The rate of recovery of Cucurbit[ n=6 - 8 ] urils for three guests was detected by UV spectroscopy. The experi- mental results revealed that in certain range of pH,the interaction of hosts and guests could be observed by using different spectrum methods. The interaction ratios of Q [ 6 ] and three guests are 1 ： 1,the ratios of Q [ 7 ] and guests are 1.5 ： 1, and the ratios of Q [ g ] and guests are 1：2. The stability constants of Q[6]with guests located between 103 -104 L＇mo1-1 ,and the stability constants of Q [ 8 ] with guests located between 1011 -1012 L2 ＂tool-2. The rate of recovery is 98% ~ 105%.