Control of supramolecular nanoassemblies by tuning the interactions of bent-shaped rod–coil molecules. Issue 18 (19th April 2017)

• Record Type: Journal Article
• Authors: You, Shengnan; Zhong, Keli; Jin, Long Yi
• Is Part Of: Soft matter. Volume 13:Issue 18(2017)
• Page Start: 3334
• Page End: 3340
• Publication Date: 2017-04-19
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/c7sm00615b
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : Bent-shaped rod–coil molecules incorporating lateral alkyl groups can self-assemble into various supramolecular nanostructures in bulk and in aqueous solution, through tuning the molecular interaction. The result reveals that the lateral groups strongly influence the creation of supramolecular nanostructures. Abstract : Rod–coil molecules1a, 1b and2a, 2b, consisting of biphenyl and phenyl units connected by an acetylene bond as the rod segment and oligo(ethylene glycol) (OEG) as the coil segment, were synthesized and characterized. Molecules1a and1b incorporate a butoxy group at the apex of their bent-shaped rigid building blocks, while both1b and2b contain a lateral methyl group between the rod and coil segments. The self-assembling behavior of these molecules was investigated using DSC, SAXS, CD, AFM, and TEM in bulk and aqueous solutions. In the bulk state, 1a self-assembles into oblique columnar structures, whereas1b, incorporating butoxy and lateral methyl groups, self-assembles into three-dimensional body-centered tetragonal structures. Molecules2a and2b with no butoxy groups, and2b incorporating a lateral methyl group, self-assemble into hexagonal perforated lamellar and oblique columnar structures, respectively. In dilute aqueous solutions, 1a assembles into tubular nanoassemblies, while1b self-organizes into micelles and nanoparticles. On the other hand, 2a and2b spontaneously aggregate into nanoribbons and nanofibers. Furthermore, CD experiments together with AFM investigations of2b indicate the creation of self-organized helical fibers, implying that the lateral methyl group induces the helical stacking of the rod building block. These results reveal that the butoxy and lateral methyl groups between the rod and coil segments dramatically influence the creation of supramolecular nanostructures and morphologies.