Preparation and characterization of the inclusion complexes of poly(dimethylsilane)s with cyclodextrins
Preparation and characterization of the inclusion complexes of poly(dimethylsilane)s with cyclodextrins
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DOI：
10.1021/ma030164a
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发表时间：
2003-08-26
期刊：
影响因子：
5.5
通讯作者：
Harada, A
中科院分区：
文献类型：
--
作者：
Okumura, H;Kawaguchi, Y;Harada, A
β-环糊精（β-CD）和γ-环糊精（γ-CD）与不同分子量的聚二甲基硅烷（PSi）形成包合物，得到结晶化合物。然而，α-环糊精（α-CD）不与任何分子量的PSi形成复合物。β-CD-PSi包合物的产率随PSi分子量的增加而降低。与此相反，γ-CD-PSi包合物的产率随着分子量的增加而增加，在分子量约为760时达到最大值，并在较高分子量时逐渐降低。β-CD和γ-CD的链长选择性完全不同。γ-CD-PSi包合物的化学计量比为1：3（γ-环糊精：PS单体单元）。通过H-1 NMR、C-13 CP/MAS NMR和X-射线衍射研究对配合物进行了分离和表征。这些结果表明，CD与PSi形成通道型复合物。通过紫外吸收光谱和荧光光谱研究了其光学性质。γ-CD空腔中的PSi主链呈全反式构象。
beta-Cyclodextrin (beta-CD) and gamma-cyclodextrin (gamma-CD) formed inclusion complexes with poly(dimethylsilane)s (PSi) of various molecular weights to give crystalline compounds. However, alpha-cyclodextrin (alpha-CD) did not form complexes with PSi of any molecular weight. The yields of the beta-CD-PSi inclusion complexes decreased with increasing molecular weight of PSi. In contrast, the yields of the gamma-CD-PSi inclusion complexes increased with increasing molecular weight, reached a maximum at molecular weight of around 760, and gradually decreased at higher molecular weight. The chain-length selectivities are totally different between beta-CD and gamma-CD. The gamma-CD-PSi inclusion complexes are stoichiometric 1:3 (gamma-cyclodextrin:monomer unit of PS) compounds. The complexes were isolated and characterized by H-1 NMR, C-13 CP/MAS NMR, and X-ray diffraction studies. These results suggest that CDs form channel-type complexes with PSi. The optical properties were studied by ultraviolet absorption and fluorescence spectroscopy. The PSi main chain in the cavities of gamma-CD takes an all-trans conformation.