Liquid Crystallinity and Organogelation Behavior of Lignin-Derived Metabolic Intermediate Bearing Cholesterol Groups
Liquid Crystallinity and Organogelation Behavior of Lignin-Derived Metabolic Intermediate Bearing Cholesterol Groups
复制标题
DOI：
10.1246/bcsj.20110055
复制
发表时间：
2011-06-15
影响因子：
4
通讯作者：
Shigehara, Kiyotaka
中科院分区：
文献类型：
--
作者：
Michinobu, Tsuyoshi;Hiraki, Kenta;Shigehara, Kiyotaka
首次将两个胆固醇基团连接到木质素衍生的代谢中间体2-吡喃酮-4，6-二羧酸（PDC）上。这种PDC分子显示出液晶中间相和有趣的有机凝胶行为。分子结构和组装性能之间的关系进行了研究，通过修改PDC核心和PDC和胆固醇部分之间的间隔基团。虽然所有的衍生物显示出类似的SmA相的相变行为，只有少数可以形成有机凝胶。通过X-射线衍射（XRD）和扫描电子显微镜（SEM）的干凝胶的详细的形态学研究表明，PDC部分和氨基甲酸酯间隔是必不可少的有机凝胶的发生。氨基甲酸酯间隔基的氢键和胆固醇部分的货车范德华相互作用导致吡喃酮环的偶极诱导的相互作用。物理凝胶可能是通过这些协同作用而稳定的。IR和H-1 NMR光谱清楚地揭示了存在弱的分子间相互作用，如氢键和偶极型相互作用，有效的胶凝剂分子。
Two cholesterol groups were for the first time attached to a lignin-derived metabolic intermediate, 2-pyrone-4,6-dicarboxylic acid (PDC). This PDC molecule showed a liquid crystalline mesophase and interesting organogelation behavior. The relationship between molecular structure and assembly properties was investigated by modifying the PDC core and a spacer group between the PDC and cholesterol moieties. Although all derivatives displayed similar phase transition behavior with a SmA phase, only a few of them could form organogels. Detailed morphology investigations of the xerogels by X-ray diffraction (XRD) and scanning electron microscopy (SEM) suggested that both the PDC moiety and a carbamate spacer are essential for the occurrence of organogelation. Hydrogen bonds of the carbamate spacers and van der Waals interactions of the cholesterol moieties lead to a dipolar-induced interaction of the pyrone rings. The physical gels were probably stabilized by these cooperative interactions. The IR and H-1 NMR spectroscopies clearly revealed the presence of weak intermolecular interactions, such as hydrogen bonds and dipolar-type interactions, for efficient gelator molecules.