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本文报道六种非手性芳香冠醚,即苯并-15-c-5,苯并-18-c-6,4-叔丁基苯并-15-c-5,二苯并-18-c-6,二苯并-24-c-8,4,4’二叔丁基二苯并-30-c-10,在3:2水-甲醇体系中同β-环糊精配位时的紫外光谱及诱导出的圆二色性谱。有趣的是,这些冠醚的邻苯二酚基生色团的~1A_1←~1A_1及~1B_2←~1A_1跃迁区的每一个谱带区均诱导出负正交替的圆二色性,经用Job连续变量法及摩尔比法确定系有两种配合物生成,一种是2:1 β-环糊精-冠醚配合物,另一种是1:2 β-环糊精-冠醚配合物。应用Shimizu等的理论结果,确定了含邻苯二酚基生色团的冠醚在β-环糊精空腔中的取向及其包结形态。就2:1配合物而言,本质上是一种亲脂相互作用,它遵循环糊精包结物的一般规律。对于1:2的β-环糊精-冠醚配合物,不存在β-环糊精空腔对冠醚的邻苯二酚基生色团的包结作用,所以推断其结构可能是,二个冠醚分子分别从β-环糊精圆筒的两端将环糊精分子包结起来,彼此间的作用是一种亲水相互作用。
Six kinds of achiral aromatic crown ethers were reported in this paper, namely benzo-15-c-5, benzo-18-c- c-6, dibenzo-24-c-8,4,4 ’di-tert-butyldibenzo-30-c-10 in the 3: 2 water-methanol system The UV spectrum and induced circular dichroism spectrum. Interestingly, the catechol-based chromophores in these crown ethers induced negatively-orthorhombic circular dichroism in each of the 1A_1 ← ~ 1A_1 and ~ 1B_2 ← ~ 1A_1 transitions Job continuous variable method and the molar ratio method to determine the Department of the two complexes, one is 2: 1 β-cyclodextrin - crown ether complex, and the other is 1: 2 β-cyclodextrin - crown ether with Things. Using the theoretical results of Shimizu et al., The orientation of the crown ether containing the catechol-based chromophore in the β-cyclodextrin cavity and its inclusion morphology were determined. In the case of a 2: 1 complex, it is essentially a lipophilic interaction that follows the general rules for cyclodextrin inclusion. For the 1: 2 β-cyclodextrin-crown ether complex, there is no inclusion of β-cyclodextrin cavity on the catechol-based chromophore of crown ether, so it is concluded that its structure may be that bis Crown ether molecules enclose the cyclodextrin molecules from both ends of the β-cyclodextrin cylinder, respectively, and the interaction between them is a hydrophilic interaction.