A Self‐Assembled Bicontinuous Cubic Phase with a Single‐Diamond Network

Abstract

The first single-diamond cubic phase in al iquid crystal is reported. This skeletal structure with the Fd " 3mspace group is formed by self-assembly of bolaamphiphiles with swallow-tailed lateral chains.I tc onsists of bundles of pconjugated p-terphenyl rods fused into an infinite network by hydrogen-bonded spheres at tetrahedral four-way junctions. We also present aq uantitative model relating molecular architecture to the space-filling requirements of six possible bicontinuous cubic phases,t hat is,t he single-and doublenetwork versions of gyroid, diamond, and "plumber'sn ightmare".Among the most intriguing self-assembled nano-and mesoscale soft-matter structures are the cubic phases formed by lyotropic and thermotropic liquid crystals (LCs), by block copolymers, [1,2] and by nanoparticle arrays. [3][4][5] Tw o classes of cubic phases can be distinguished, the "bicontinuous" and the "micellar" types. [6,7] Them icellar phases represent periodic arrays of spheres on ac ubic lattice, whereas the bicontinuous phases are more complex and usually formed by two networks divided by aminimal surface with aconstant mean curvature.Depending on the symmetry, the double gyroid (DG, Ia " 3d,Q 230 ), the double diamond (DD; Pn " 3m,Q 224 ), and the body-centered plumber'sn ightmare ("double primitive") cubic phases (DP; Im3 m,Q 229 )w ith junction valencies of n = 3, 4, and 6, respectively,c an be distinguished (Figure 1a-c). Figure 6. Models showing a) the micellar Fd " 3m cubic phase [27,28] and b) the new SD bicontinuous cubic phase of compounds 1/18-11/22.

Synthesis of cis‐1,2‐diol‐type chiral ligands and their dioxaborinane derivatives: Application for the asymmetric transfer hydrogenation of various ketones and biological evaluation

“…π* transition of non-bonded electrons of imine (C=N) groups or π-tovacant B p-orbital transition was observed in the range 357-527 nm in C 2 H 5 OH or CHCl 3 , respectively. [47] The NMR ( 1 H, 13 C, and 11 B) spectral data were in good agreement with the proposed structures in CDCl 3 or DMSO-d 6 ( Figure S1-S16 in the ESI). The major difference between the 1 H NMR spectra of ligands (T 1 and T 2 ) and their complexes (T (1-2) B (1-2) ) and (T (1-2) B (1-2) -N) is the presence of a new signal for the boronic acid groups and 4-tert-butyl pyridine ( Figure S1-S10 in the ESI).…”

“…π* transition of non-bonded electrons or π-to-vacant B p-orbital transitions. [47] In view of the this results, the strong broad absorption bands in the range 218-346 nm in C 2 H 5 OH or CHCl 3 , respectively, can be attributed to the π ! π* transitions of aromatic benzene ring.…”

Chirality Induction through Nano‐Phase Separation: Alternating Network Gyroid Phase by Thermotropic Self‐Assembly of X‐Shaped Bolapolyphiles

“…[20] Fors uch "normal" wedges it has been shown that ak ey determinant of the adopted phase type is the dV/dr function, describing how volume increases as one moves along r from the apex (r = 0) toward the wide end of the wedge. [21] The same principle can be applied to the present inverse wedges. As af irst approximation, the cross-section area A of the wedge is A(r) / dV/dr / r q .H ere q % 1( slice or triangle shape) suites ac olumnar phase (Figure 4a), q % 0( rectangle, matching aromatic and aliphatic cross-sections) suits alamellar phase (Figure 4c), while 0 < q < 1( shield shape) is most likely to adopt aCub bi phase (Figure 4b).…”

Spontaneous mirror symmetry breaking in benzil-based soft crystalline, cubic liquid crystalline and isotropic liquid phases

“…The method of selecting the correct phase combination is described in previous work. 12 , 25 , 27 The cubic lattice parameter is around 11–13 nm for Ia 3[combining macron] d and 18 nm for I 23 [ * ] , in line with a double- and triple-network structure, respectively. Remarkably, the Ia 3[combining macron] d lattice is the largest for the smallest molecule 3/2 ( L mol = 4.4 nm; a cub = 12.9 nm) and becomes smaller for the Ia 3[combining macron] d phases of the larger compounds 3/12–3/16 with much longer chains ( L mol = 5.8–6.3 nm; a cub = 11.3–11.5 nm).…”