Four new donor-acceptor triads (D-A-D) based on discotic and arylene mesogens have been synthesized by using Sonogashira coupling and cyclization reactions. This family of triads consists of two side-on pending triphenylene mesogens, acting as the electron-donating groups (D), laterally connected through short lipophilic spacers to a central perylenediimide (PI), benzo[ghi]perylenediimide (BI), or coronenediimide (CI) molecular unit, respectively, playing the role of the electron acceptor (A). All D-A-D triads self-organize to form a lamello-columnar oblique mesophase, with a highly segregated donor-acceptor (D-A) heterojunction organization, consequent to efficient molecular self-sorting. The structure consists in the regular alternation of two disrupted rows of triphenylene columns and a continuous row of diimine species. High-resolution STM images demonstrate that PI-TP2 forms stable 2D self-assembly nanostructures with some various degrees of regularity, whereas the other triads do not self-organize into ordered architectures. The electron-transport mobility of CI-TP2, measured by time-of-flight at 200 °C in the mesophase, is one order of magnitude higher than the hole mobility. By means of this specific molecular designing idea, we realized and demonstrated for the first time the so-called p-n heterojunction at the molecular level in which the electron-rich triphenylene columns act as the hole transient pathways, and the coronenediimide stacks form the electron-transport channels.

Circularly polarized luminescence (CPL) derived from supramolecular self-assembly chirality has been a fascinating field of research due to its applications in photoactive devices and bioactive probes. Herein, we report a straightforward pathway for the construction of efficient chirality transfer and enhanced circularly polarized phosphorescence based on platinum­(II) metallomesogens via liquid crystal self-organization. Overall, two chiral metallomesogens, the enantiomeric complexes of (S)-Pt-L1 and (R)-Pt-L1, were obtained based on the combination of the rodlike achiral phenylpyridine and point-chiral pyridinic acid derivatives. Experiments with polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and variable-temperature X-ray diffraction show that there are two smectic phases during cooling and heating processes, namely the high temperature SmC* and low temperature SmC phases, and the SmCh* phase. Interestingly, the circular dichroism (CD) and circularly polarized luminescence (CPL) tests reveal that the chirality transfer from the molecule to liquid crystal self-organization does occur indeed in the high temperature SmC* and SmCh* phases. However, both the CD and CPL signals are silent in the low temperature SmC phase, even in the solution, suggesting that chirality transfer depends on the self-organization superstructure of the liquid crystal. Moreover, the dissymmetry factor (|g lum| = 4.0 × 10–2) in the high temperature SmC* phase is 1–2 orders of magnitude higher than that of Pt­(II) complexes previously reported. Also, the elevated photoluminescence quantum yield (ΦPL = 0.46) is obtained for the liquid crystal film, indicating that the enhanced CPL properties can be achieved through self-organization of mesomorphic organoplatinum molecules. Another interesting observation is made that the racemic mixture ((S)-Pt-L1 and (R)-Pt-L1) shows spontaneous chirality separation in the high temperature SmC1 phase.

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Obtaining homochirality from biased symmetry‐breaking of self‐assembly in achiral molecules remains a great challenge due to the lack of ingenious strategies and controlling their handedness. Here, we report the first case of biased symmetry breaking from achiral platinum (II) liquid crystals which self‐organize into an enantiomerically enriched single domain without selection of handedness in twist grain boundary TGB [*] phase. Most importantly, the chiral control of self‐organization can be achieved by using above the homochiral liquid crystal films with determined handedness (P or M) as a template. Moreover, benefiting from self‐assembled superhelix, these complexes exhibit prominent circularly polarized luminescence with high |glum| up to 3.4×10−3 in the TGB [*] mesophase. This work paves a neoteric avenue for the development of chiral self‐assemblies from achiral molecules.

Water as a common, easily obtained, and environmentally friendly stimulus has been explored in stimuli-responsive materials. In this paper, a series of composites, named as PVA­(n)-CMC­(m)-GA, were prepared by filling the carboxymethyl cellulose sodium (CMC) into chemical cross-linked poly­(vinyl alcohol) (PVA). These composites demonstrated both water induced shape memory and self-healing effect. CMC with water sensitivity help the composite absorbing water to decrease the T g of composite to cause shape recovery. And CMC with water solubility is also a good healing agent, which can freely move across the cutting cross-section in wet condition and form hydrogen bonds with PVA chains in dry condition to achieve healing. Water can affect the hydrogen bonding interactions between CMC and PVA, and which play a key role in the water-stimuli responsive properties. This study provides a relatively simple and low cost way to obtain water-induced multifunction materials.

Pd‐catalyzed Suzuki cross‐coupling reactions between arylboronic acids and bromoarenes have been applied widely in the synthesis of liquid‐crystalline materials. However, aryl triflate derivatives have been less used despite their high chemical tolerance, reactivity, and chemical accessibility. In this report, three series of discogens have been synthesized in good yields from appropriate triphenylene triflate precursors by Suzuki coupling reactions with various commercial arylboronic acids (e.g., aryl = phenylene, thiophene, naphthalene, triarylamine, carbazole, and fluorene). The synthesized discogens display broad mesophase ranges and high thermal stabilities. Moreover, those bearing triarylamine, carbazole, and fluorene side groups are also blue‐light emitters. The availability of the triflate precursors coupled with their highly efficient cross‐coupling with commercial arylboronic acids make this strategy extremely versatile and attractive for the design of new functional materials.

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A copper-catalyzed amination of aryl halides with nitriles has been developed. The use of nitriles as nitrogen nucleophiles can make the synthesis of N-arylamides more simple than that using amides through in-situ hydrolysis. A variety of N-arylamides and benzoxazole derivatives can be synthesized according to this approach.