Yang Yuntian, Chen Fengchun, Tian Xizhe, Chen Tie, Wu Lixin, Jin Long Yi
Key Lab for Organism Resources of the Changbai Mountain and Functional Molecules, and Department of Chemistry, College of Science, Yanbian University, No. 977 Gongyuan Road, Yanji 133002, People's Republic of China.
Soft Matter. 2019 Aug 21;15(33):6718-6724. doi: 10.1039/c9sm01279f.
Coil-rod-coil molecules, composed of flexible oligoether chains and conjugated rod blocks, have a well-known ability to produce various nanostructures in bulk and in aqueous solution. Herein we report the synthesis and self-assembly of coil-rod-coil molecules based on the sequence of the rod building block and the type of oligoether coil chain. These molecules consist of conjugated rod segments, which are composed of biphenyl, terphenyl, and acetylenic bonds, with chiral oligoether chains as flexible coil segments. The experimental results imply that the sequence of the rod segments markedly influences the self-assembled nanostructures of coil-rod-coil molecules in the bulk state, and that the type of coil chain strongly affects the morphology of the supramolecular nanoassemblies of these molecules in aqueous solution. In the bulk state, molecules 1a and 1b, which contain biphenyl units connected to the end of the coil segments self-organize into a hexagonal perforated lamellar phase, and oblique columnar and body-centred tetragonal structures, respectively. However, molecules 2a and 2b bearing terphenyl units linked to the end of the coil segments self-assemble into lamellar, hexagonal perforated lamellar and hexagonal columnar structures. In aqueous solution, rod-coil molecular isomers with linear chiral oligoether chains self-assemble into helical nanofibres of various lengths. Meanwhile, isomers with chiral oligoether dendron chains self-organize into sheet-like nanoribbons of different sizes.
由柔性低聚醚链和共轭棒状嵌段组成的线圈-棒-线圈分子，具有在本体和水溶液中产生各种纳米结构的众所周知的能力。在此，我们报告基于棒状结构单元的序列和低聚醚线圈链的类型的线圈-棒-线圈分子的合成和自组装。这些分子由共轭棒段组成，共轭棒段由联苯、三联苯和炔键构成，以手性低聚醚链作为柔性线圈段。实验结果表明，棒段的序列显著影响线圈-棒-线圈分子在本体状态下的自组装纳米结构，并且线圈链的类型强烈影响这些分子在水溶液中的超分子纳米聚集体的形态。在本体状态下，含有连接到线圈段末端的联苯单元的分子1a和1b分别自组装成六方穿孔层状相、斜柱状和体心四方结构。然而，带有连接到线圈段末端的三联苯单元的分子2a和2b自组装成层状、六方穿孔层状和六方柱状结构。在水溶液中，具有线性手性低聚醚链的棒-线圈分子异构体自组装成各种长度的螺旋纳米纤维。同时，具有手性低聚醚树枝状链的异构体自组装成不同尺寸的片状纳米带。
