摘要
H-shaped, n-shaped, bent-shaped and linear rod-coil molecules, consisting of biphenyls and a p-terphenyl or phenyl unit linked together with ether bonds as a rod segment and poly(ethylene oxide)(PEO) with various degree of polymerization as coil segments were synthesized. These molecules contain lateral alkyl groups in the middle of benzene ring and lateral methyl groups between the rod and coil segments. The self-assembling behavior of these molecules was investigated by means of DSC, POM, AFM, TEM and SAXS in the bulk and aqueous solutions. Molecules with non lateral units self-assemble into a lamellar and a hexagonal perforated layer structure in the crystalline phase and the liquid crystalline phase, respectively. While, molecules incorporating lateral methyl groups between the rod and coil segments spontaneously self organize into hexagonal perforated layer, oblique columnar or 3-D body centered tetragonal structures. In aqueous solutions, molecules with non lateral units self-assemble into nanoribbon or fibrous aggregates, whereas, molecules with a lateral groups exhibit self-organizing capacity to form helical fibers. Notably, CD experiments together with AFM investigations of these molecules reveal that the helical sense switches to opposite-handedness, depending on the temperature of aqueous solution. These results reveal that self-assembling behavior of these molecules is dramatically influenced by lateral alkyl groups in the middle of rod segment and lateral methyl groups between the rod and coil segments.
H-shaped, n-shaped, bent-shaped and linear rod-coil molecules, consisting of biphenyls and a p-terphenyl or phenyl unit linked together with ether bonds as a rod segment and poly(ethylene oxide)(PEO) with various degree of polymerization as coil segments were synthesized. These molecules contain lateral alkyl groups in the middle of benzene ring and lateral methyl groups between the rod and coil segments. The self-assembling behavior of these molecules was investigated by means of DSC, POM, AFM, TEM and SAXS in the bulk and aqueous solutions. Molecules with non lateral units self-assemble into a lamellar and a hexagonal perforated layer structure in the crystalline phase and the liquid crystalline phase, respectively. While, molecules incorporating lateral methyl groups between the rod and coil segments spontaneously self organize into hexagonal perforated layer, oblique columnar or 3-D body centered tetragonal structures. In aqueous solutions, molecules with non lateral units self-assemble into nanoribbon or fibrous aggregates, whereas, molecules with a lateral groups exhibit self-organizing capacity to form helical fibers. Notably, CD experiments together with AFM investigations of these molecules reveal that the helical sense switches to opposite-handedness, depending on the temperature of aqueous solution. These results reveal that self-assembling behavior of these molecules is dramatically influenced by lateral alkyl groups in the middle of rod segment and lateral methyl groups between the rod and coil segments.
引文
[1]Yang Liu,Keli Zhong,Zhaohua Li,Tie Chen,Myoongsoo Lee,Long Yi Jin*,Synthesis and Self-assembly of Amphiphilic Bent-Shaped Molecules Based on Dibenzo[a,c]Phenazine and Poly(ethyleneoxide)Units,Polym.Chem.2015,6,7395.
[2]Zhaoyang Lu,Keli Zhong,Yang Liu,Zhaohua Li,Tie Chen,Long Yi Jin*,Self-organizing p-quinquephenyl building blocks incorporating lateral hydroxyl groups into supramolecular nano-assemblies,Soft matter,in press.