Journal of Polymer Science Part A: Polymer Chemistry, Vol.53, No.1, 85-92, 2015
Ordered Nanostructures from Self-Assembly of H-Shaped Coil-Rod-Coil Molecules
A new class of -conjugated, skewed H-shaped oligomers, consisting of biphenyl, phenylene vinylene, and phenylene ethynylene units as the rigid segment, were synthesized via Sonogashira coupling and Wittig reactions. The coil segments of these molecules were composed of poly(ethylene oxide) (PEO) or PEO with lateral methyl groups between the rod and coil segment, respectively. The experimental results revealed that the lateral methyl groups attached to the surface of the rod and coil segments dramatically influenced the self-assembling behavior of the molecules in the crystalline phase. H-shaped rod-coil molecules containing a lateral methyl group at the surface of the rod and PEO coil segments self-assemble into a two-dimensional columnar or a three-dimensional body-centered tetragonal nanostructures in the crystalline phase, whereas molecules lacking a lateral methyl group based on the PEO coil chain self-organize into lamellar or hexagonal perforated lamellar nanostructures. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 85-92