In memory of Tadatomi NishikuboChirality is one of the fundamental issues in the related fields of biology, medicine, chemistry, and physics, [1] because components of life, medicine, and display devices are composed of chiral molecules, such as DNA, proteins, cellulose, sugar, amino acids, drugs, and liquid crystalline molecules. However, chirality is not restricted to these molecular regimes. Solid minerals and inorganic materials also have chirality, which arises from the geometric properties and the atomic structure of surfaces. [1][2][3] A difference between molecular and mineral chirality would be in its resilience; the former is temporary at the limited environment, while the latter will be semi-permanent even under the harsh conditions. Therefore, artificial chiral minerals would have great potential for memory, preservation, and development of organic chiral systems.Helical mesoporous silica, which was pioneered by Tatsumi et al, [4] is one of current topics in chiral mineral materials. Its chirality is induced by a templated sol-gel reaction where special micelles self-assembled from chiral molecules serve as templates to direct helical morphology, thereby imprinting the chiral topology in silica. [4,5] Although this is a refined process to simultaneously control the morphology and chirality, in conventional chiral mesoporous silica formation, the hydrolytic condensation of alkoxysilane is catalyzed by the added HCl or NaOH solution rather than by micellar template itself. [6][7][8][9] In the design of silica materials, the greatest designer and authority is surely biosilica, such as diatoms and sponges, which have very beautiful, complex, and sophisticated shapes in nano-and microdimensions with silica skeletons. [10][11][12][13] In this sense, diatoms and sponges are eternal texts with a lot of sources of inspiration for the synthesis of silica-based nano/microscale materials, including chiral silica. It is well known that in the biogenic silica formation, organized organic matrices, such as silaffins (polypeptides), silicateins (proteins), and long-chain polyamines play as catalysts (temporal control) and templates (spatial control) in silica deposition under neutral pH and ambient conditions. [14][15][16][17][18][19][20][21][22][23][24] As mimicking those organic matrices, a lot of organic molecules and polymers having amino groups have been used in the biomimetic silica deposition, and major achievements have been accomplished in this field over the past decade. [25][26][27][28][29][30][31][32][33][34][35][36][37] However, no efforts were put on the construction of chiral silica, although many biomimetic silicas were deposited by co-precipitation with chiral polypeptides. [25][26][27][28] Among biomimetic silica formation, the silicateins particularly attracted our interest because they form axial filaments (fibrils) and act as templates to deposit silica around the surface of the fibrils to give fibrous hybrids consisted of axial filaments and silica shell. [20,22,23] Recently, we have established...

Multifunctional 6-membered cyclic carbonates (6-CCs) comprising acetal structures have been synthesized via phosgene-free routes and utilized for the fabrication of reworkable networked poly(acetal-hydroxyurethane) (PAHU) films. Dibenzoyl-protected di(trimethylolpropane) (DTMP) reacts with multifunctional aldehydes derived from nonexpensive alcohols to afford protected multifunctional DTMPs. After deprotection, the multifunctional DTMPs can react with diphenyl carbonate to efficiently form multifunctional 6-CCs. The polyaddition of the 6-CCs and diamines effectively proceeds in DMF to give networked PAHU films with good transparency and flexibility. These films possess the reworkability based on acid-catalyzed reversibility of acetal linkages. In particular, the film fabricated using large amounts of hexa-functional 6-CCs can reform reproducibly with maintaining to some degree its mechanical properties.

Ferroelectricity in fluid materials, which allows free rotation of molecules, is an unusual phenomenon raising cutting‐edge questions in science. Conventional ferroelectric liquid crystals have been found in phases with low symmetry that permit the presence of spontaneous polarization. Recently, the discovery of ferroelectricity with high symmetry in the nematic phase has attracted considerable attention. However, the physical mechanism and molecular origin of ferroelectricity are poorly understood and a large domain of macroscopically oriented spontaneous polarization is difficult to fabricate in the ferroelectric nematic phase. This study reports new fluid layered ferroelectrics with the C∞v symmetry in which nearly complete orientation of the spontaneous polarization remains stable under zero electric field without any orientation treatment. These ferroelectrics are obtained by simplifying the molecular structure of a compound with a known ferroelectric nematic phase, although the simplification reduced the dipole moment. The results provide useful insights into the mechanism of ferroelectricity due to dipole–dipole interactions in molecular assemblies. The new ferroelectric materials are promising for a wide range of applications as soft ferroelectrics.

Linear Fe(II) 1,2,4-triazole complexes with lipid counteranions are newly developed. These complexes show sharp and reversible spin conversion in toluene, with temperatures significantly higher (by 20-100 K) than the spin crossover temperatures observed in the crystalline states. This is accounted for in terms of increased metal-ligand interactions in organic media, which is caused by solvophobic compaction of charged coordination chains. In atomic force microscopy, developed nanowires are observed for low spin (LS) complexes. On the other hand, fragmented nanostructures are seen for high spin (HS) complexes, indicating that the spin conversion in solution is governed by a self-assembly process. The lipid packaging of charged coordination chains thus provides powerful means to improve and regulate their functions via solvophobic self-assembly.

Lipophilic, linear iron(II) 1,2,4-triazole complexes with 9,10-dimethoxyanthracene-2-sulfonate and 1-pyrenesulfonate counter ions are newly developed. These complexes are dispersed in toluene as nanofibers and display dynamic spin conversion characteristics. Photorelaxation process of 1-pyrenesulfonate accumulated on the complex is regulated depending on the spin state of iron(II) triazole complexes.