Induced Twisting in the Self-Assembly of Chiral Schiff-based Rod−Coil Amphiphiles

Abstract

A series of novel organic superstructures exhibiting diverse aggregate morphologies with liquidcrystalline-like properties were prepared by a simple precipitation method. Here, a chiral sugar moiety was simply introduced at the Schiff-based rod end of rod-coil molecules. In contrast to coil-coil molecules, the self-assembled rod-coil molecules exhibit a high segregation strength for phase separation because of their liquid-crystalline-like behavior. The morphological transformation of self-assembled chiral Schiff-based rod-coil amphiphiles, from a platelet-like morphology to helical twists, was obtained by increasing the length of the hydrophobic tail. Consistent with theoretical predictions, the bending force from the chiral entity depends on the size of the adjacent hydrophobic tail. That is, the size of hydrophobic chain determines the threshold of bending for the formation of a helical morphology. Moreover, by introducing an additional tethered hydrophobic chain self-assembled spherical vesicles can be obtained through the collapse of the twisted shape.

Self-assembly behavior of ABA coil-rod-coil triblock copolymers: A Brownian dynamics simulation approach

“…43 It is also like a helical ribbon observed in many experiments. 44 Selinger et al have done large amounts of theoretical and simulation surveys in order to explain the formation of tubules and helical ribbons in systems of chiral amphiphilic molecules. [45][46][47] Their theories are based on a continuum elastic free energy that allows a direction of molecular tilt in the curvature of the membrane, showing that the formation of tubules and helical ribbons is driven by the curvature of the membranes, and their predictions are consistent with experiments.…”

Self-assembly of chiral amphiphiles with π-conjugated tectons

“…When tetraethyl orthosilicate (TEOS) is used as the source of silica, hydrogen bond formation is possible between TEOS and the sugar based surfactant, like C 4 AG (Figure 6). In this way, TEOS was effectively adsorbed to the surface of the double helices formed by C 4 AG, which allows for the formation of delicate double helical SiO 2 nanotubes) [69]. Interestingly, upon decoupling the double helices by addition of CTAB to the C 4 AG system, single helical SiO 2 nanotubes can be obtained as well.…”

Solvent-tuned multiple self-assembly of a new sugar-appended gelator

“…These primary structures grow and aggregate further to give rise to various higher structures, such as rods, planar tapes, twisting ribbons, helical ribbons, fibrils, and tubes [2,15]. The control of self-assembled morphologies via modulation of the secondary interactions is an active field of current interest [6,[16][17][18][19][20][21][22]. This can * Corresponding author.…”

“…Biphenyl-β-O-d-glucosides, e.g., 4-(4 -propoxyphenyl)phenyl-β-O-d-glucoside and 4-(4 -decyloxyphenyl)phenyl-β-O-d-glucoside [35], are known to have an enhanced mesophase stability in relation to β-O-d-n-dodecylglucoside due to their additional π-π stacking of rigid biphenyl units. However, although the π-π interaction between aromatic rings of Schiff-based glycolipid is considered to be indispensable for the formation of helical structure [16], to the best of our knowledge, no successful effort has been made to employ such kinds of glycolipids as a gelator. As we will show hereafter, the newly designed LMMG 1 is able to gel water and a variety of organic solvents via hierarchical self-assembly.…”