Structural Studies of Stereo-selective Inclusion of Guest Molecules by Chiral Host Molecules

点击翻译按钮获取中文摘要

Structure of <delta> -cyclodextrin, composed of nine D-glucopyranose units, is similar to those of <alpha> -, <beta> -, and <gamma> -cyclodextrin at R=0.35 stage.Structure of <beta> -cyclodextrin 11.6 <H_2> O was determined at -80゜C, The results show the water molecules in the host-cavity seem to be rearranged at -46゜C.Structure of <beta> -cyclodextrin.salicylic acid molecular complex was determined and was compared with that of <beta> -cyclodextrin.aspirin.salicylic acid complex. From the results, the cavity of <beta> -cyclodextrin can recognize the shape of guest molecules, and includes the guests by closest van der Waals contacts between host-guest and guest-guest molecules.Molecular complexes between <beta> -cyclodextrin and R,S-methyl-p-trylsulfoxide, S-methyl-p-trylsulfoxide, and R,R,R-, S,S,S-allethrin were crystallized and their crystal structures were determined. Although the host structures were clearly elucidated, the guests were in highly disordered state in the three host-guest complexes.