Construction of Supramolecular Assemblies from Self-Organization of Amphiphilic Molecular Isomers

Zhaohua Li; Yuntian Yang; Yanqiu Wang; Tie Chen; Long Yi Jin; Myongsoo Lee

doi:10.1002/asia.201600683

Construction of Supramolecular Assemblies from Self-Organization of Amphiphilic Molecular Isomers

Chem Asian J. 2016 Aug 19;11(16):2265-70. doi: 10.1002/asia.201600683. Epub 2016 Jul 29.

Authors

Zhaohua Li¹, Yuntian Yang¹, Yanqiu Wang², Tie Chen¹, Long Yi Jin³, Myongsoo Lee⁴

Affiliations

¹ Key Laboratory for Organism Resources of the Changbai Mountain and Functional Molecules, Ministry of Education, Department of Chemistry, Yanbian University, Yanji, 133002, China.
² State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, China.
³ Key Laboratory for Organism Resources of the Changbai Mountain and Functional Molecules, Ministry of Education, Department of Chemistry, Yanbian University, Yanji, 133002, China. lyjin@ybu.edu.cn.
⁴ State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, China. mslee@jlu.edu.cn.

PMID: 27348276
DOI: 10.1002/asia.201600683

Abstract

Amphiphilic coil-rod-coil molecules, incorporating flexible and rigid blocks, have a strong affinity to self-organize into various supramolecular aggregates in bulk and in aqueous solutions. In this paper, we report the self-assembling behavior of amphiphilic coil-rod-coil molecular isomers. These molecules consist of biphenyl and phenyl units connected by ether bonds as the rod segment, and poly(ethylene oxide) (PEO) with a degree of polymerization of 7 and 12 as the flexible chains. Their aggregation behavior was investigated by differential scanning calorimetry, thermal optical polarized microscopy, small-angle X-ray scattering spectroscopy, and transmission electron microscopy. The results imply that the molecular structure of the rod building block and the length of the PEO chains dramatically influence the creation of supramolecular aggregates in bulk and in aqueous solutions. In the bulk state, these molecules self-organize into a hexagonal perforated lamellar and an oblique columnar structure, respectively, depending on the sequence of the rod building block. In aqueous solution, the molecule with a linear rod segment self-assembles into sheet-like nanoribbons. In contrast, its isomer, with a rod building block substituted at the meta-position of the aryl group, self-organizes into nanofibers. This is achieved through the control of the non-covalent interactions of the rod building blocks.

Keywords: amphiphiles; coil-rod-coil structures; nanofibers; nanostructures; self-assembly.