Preparation of dicholesteryl-derivatives:The effect of spatial configuration upon gelation  

作　　者：YAN Ni ZHANG HeLan XU ZhiYan FANG Yu 

机构地区：[1]Key Laboratory of Applied Surface and Colloid Chemistry,Ministry of Education,School of Chemistry and Chemical Engineering,Shaanxi Normal University,Xi’an 710062,China

出　　处：《Chinese Science Bulletin》2012年第33期4310-4321,共12页

基　　金：supported by the National Natural Science Foundation of China (20902055,20927001,91027017,21273141);the 13115 Project of Shaanxi Province (2010ZDKG-89);the Program for Changjiang Scholars and Innovative Research Team in University of China (IRT1070)

摘　　要：To investigate the effect of spatial configuration on the gelation properties of low molecular mass gelators(LMMGs),four novel di-cholesteryl derivatives have been specially designed and synthesized by introducing the cis-/trans-isomers of butene diacid and the optical isomers of D/L-phenylalanine into the linker between two cholesteryl moieties.These isomers have been denoted as MaDC,FaDC,MaLC and FaLC,respectively.The gelation properties of the compounds were examined in 26 organic solvents,and it was found that the trans-configuration is more favorable for the gelation,but the chirality of the linker shows little effect to the gelation.FaDC has the strongest gelation ability among the four isomers.Interestingly,FaDC and FaLC display phase-selective gelation of benzene,toluene and xylene from their mixtures with water at room temperature,which establishes a foundation for the purification of water contaminated by oil or aromatic solvents.SEM and CD spectroscopy studies revealed that the spatial configuration of the linkers of the gelators affects significantly the aggregation mode,the morphologies and the chirality of the network of the gels.Moreover,the different aggregation behaviors also have an impact on mechanical properties of the gels,which are consistent with the results from rheological studies.Furthermore,temperature-and concentration-dependent 1 H NMR and FTIR measurements demonstrated that intermolecular hydrogen bonding and-stacking are the main driving forces for the formation of the gels.To investigate the effect of spatial configuration on the gelation properties of low molecular mass gelators （LMMGs）, four novel di-cholesteryl derivatives have been specially designed and synthesized by introducing the cis-/trans-isomers of butene diacid and the optical isomers of D/L-phenylalanine into the linker between two eholesteryl moieties. These isomers have been denoted as MaDC, FaDC, MaLC and FaLC, respectively. The gelation properties of the compounds were examined in 26 organic solvents, and it was found that the trans-configuratJon is more favorable for the gelation, but the chirality of the linker shows little effect to the gelation. FaDC has the strongest gelation ability among the four isomers. Interestingly, FaDC and FaLC display phase-selective gelation of benzene, toluene and xylene from their mixtures with water at room temperature, which establishes a foundation for the purification of water contaminated by oil or aromatic solvents. SEM and CD spectroscopy studies revealed that the spatial configuration of the linkers of the gelators affects significantly the aggregation mode, the morphologies and the chirality of the network of the gels. Moreover, the different aggregation behaviors also have an impact on mechanical properties of the gels, which are consistent with the results from rheological studies. Furthermore, temperature- and concentration-dependent 1H NMR and FTIR measurements demonstrated that intermolecular hydrogen bonding and π-π stacking are the main driving forces for the formation of the gels.

关 键 词：凝胶化性能 胆甾醇衍生物 空间配置 L-苯丙氨酸 光学异构体 工具 制备 低分子量 

分 类 号：O648.17[理学—物理化学]