Synthesis and self‐assembly of rod‐coil molecules with n‐shaped rod building block

Abstract

The rod-coil molecules with n-shaped rod building block, consisting of an anthracene unit and two biphenyl groups linked together with acetylenyl bonds at the 1,8-position of anthracene as a rigid rod segment, and the alkyl or alkyloxy chains with various length (i.e., methoxy-(1), octyl-(2), hexadecyl-(3)) at the 10-position of anthracene and poly(ethylene oxide) with the number of repeating units of 7 connected with biphenyl as coil segments were synthesized. The molecular structures were characterized by 1 H NMR and MALDI-TOF mass spectroscopy. The self-assembling behavior of new type of molecules 1-3 was investigated by means of DSC, POM, and SAXS at the bulk state. These molecules with a n-shaped rod building block segment self-assemble into supramolecular structures through the com-bination of p-p stacking of rigid rod building blocks and microphase separation of the rod and coil blocks. SAXS studies reveal that molecules 1 and 2 show hexagonal columnar and rectangular columnar structures in the liquid crystalline phase, respectively; meanwhile, molecules 1-3 self-organize into lamellar structures in the crystalline state. In addition, self-assembling studies of molecules 1-3 by DLS and TEM indicated that these molecules self-assemble into elongated nanofibers in aqueous medium.

Liquid Crystalline Assembly of Coil-Rod-Coil Molecules with Lateral Methyl Groups into 3-D Hexagonal and Tetragonal Assemblies

“…For molecule 1b , X-ray diffraction patterns shown in Figure 3a can be indexed as the (100), (110), (210) and (310) planes that correspond to a two-dimensional rectangular columnar with lattice constants a = 7.9 nm, b = 5.2 nm (Table 3) [32,33]. From the experimental values of the unit cell parameters ( a , b , c ) and the density ( ρ = 1.02), the average number ( n ) of molecules per cross-sectional slice of the column is calculated as about 8, according to Equation (1).…”

“…Compounds 3 – 5 and phosphonium salt 7 (see Supplementary Information) was synthesized according to the procedure described elsewhere [31,33,34]. …”

Supramolecular honeycomb and columnar assemblies formed by self-assembly of coil-rod-coil molecules with a conjugated rod segment

“…[1][2][3][4][5][6][7][8] An example of self-assembling molecules is provided by coil-rod-coil molecules, which have a strong tendency to self-organize into a variety of supramolecular structures on the nano-scale through weak intermolecular forces, such as hydrogen bonding, donor-acceptor interactions, electrostatic interactions, repulsive interactions and reversible ligand-metal interactions. [9][10][11][12][13][14] It has been reported that ordered nanostructures can be precisely controlled by rod-coil block systems which self-assemble into lamellar, cylindrical, and discrete nanostructures depending on the relative volume fraction of the rod or coil segment. [15][16][17][18][19] Molecules based on a conjugated rod building block, which have unique optical and electronic properties, are of great interest due to the physical properties of these molecules or polymers and are dramatically influenced by the creation of their wellordered diverse supramolecular nano-structures.…”

Supramolecular nano-assemblies from self-assembly of ABC coil-rod-coil triblock oligomers: Construction of tetragonal perforated lamellar and columnar nano-structures

“…Various supramolecular nano-structures can be formed by self-assembly of rod building block copolymers, which have a strong capacity to self-organize into a variety of ordered nanostructures, through tuning non-covalent driving forces of rod-coil block copolymers, such as interactions of pi-pi stacking, hydrophilic and hydrophobic effects, electrostatic interaction, and so on [13][14][15][16][17][18][19][20][21]. Lee and other research groups reported that rod-coil molecules are able to self organize into unique self-assembling nanostructures, such as 1-D lamellar, 2-D columnar, cylinders, discrete bundles, ribbons, and vesicles [22][23][24][25][26][27][28][29][30][31][32][33]. One example is that Lee group has systematically studied self-assembling behavior of the linear rod-coil molecules with variation in the molecular length, but an identical rod to coil volume ratio.…”