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Unraveling the chirality transfer mechanism of polymer assemblies and controlling their handedness is beneficial for exploring the origin of hierarchical chirality and developing smart materials with desired chiroptical activities. However, polydisperse polymers often lead to an ambiguous or statistical evaluation of the structure–property relationship, and it remains unclear how the iterative number of repeating units function in the helicity inversion of polymer assemblies. Herein, we report the macroscopic helicity and dynamic manipulation of the chiroptical activity of supramolecular assemblies from discrete azobenzene‐containing oligomers (azooligomers), together with the helicity inversion and morphological transition achieved solely by changing the iterative chain lengths. The corresponding assemblies also differ from their polydisperse counterparts in terms of thermodynamic properties, chiroptical activities, and morphological control. [ABSTRACT FROM AUTHOR]

The construction of chiral superstructures through the self‐assembly of non‐chiral polymers usually relies on the interplay of multiple non‐covalent bonds, which is significantly limited by the memory ability of induced chirality. Although the introduction of covalent crosslinking can undoubtedly enhance the stability of chiral superstructures, the concurrent strong constraining effect hinders the application of chirality‐smart materials. To address this issue, we have made a first attempt at the reversible fixation of supramolecular chirality by introducing dynamic covalent crosslinking into the chiral self‐assembly of side‐chain polymers. After chiral induction, the reversible [2+2] cycloaddition reaction of the cinnamate group in the polymer chains can be further controlled by light to manipulate inter‐chain crosslinking and decrosslinking. Based on this photo‐programmable and dynamic chiral fixation strategy, a novel pattern‐embedded storage mechanism of chiral polymeric materials was established for the first time. [ABSTRACT FROM AUTHOR]

Precise control over the chirality and morphologies of polymer assemblies, a remaining challenge for both chemists and materials scientists, is receiving ever‐increasing attention in the recent years. Herein, we report the subtle manipulation of the achiral spacers from the chiral stereocenter to the azobenzene (Azo) unit, of which the chiroptical consistency or chiroptical inversion of self‐assemblies could be successfully controlled and present "two‐fold" odd‐even effect. Furthermore, morphological transitions from 0D spherical micelles, 1D worms, and nanowires to 3D vesicles, spindle‐ and dumbbell‐shaped vesicles were also unexpectedly found to exhibit odd‐even correlations. These observations were collectively elucidated by mesomorphic properties, stacking modes, chiroptical dynamics, and stimuli‐responsive behaviors. Negligible modifications to the spacer structures can enable remarkable modulation of supramolecular chirality and anisotropic topologies in polymer assemblies, which is of great significance for the design of complex chiral functional polymers. [ABSTRACT FROM AUTHOR]

The chiral self‐assembly of polymers in dispersions plays an important role in chiral chemistry and self‐assembly. In general, both polymerization‐induced self‐assembly (PISA) and post‐polymerization self‐assembly can be used to prepare polymer nanoassemblies. In chirality induction or transfer processes, the self‐assembly manner of the polymers greatly affects the chiral expression of the nanostructure and cannot be ignored in the chiral fields. Moreover, unique chiral expression and morphological transition of polymer assemblies in dispersions enable the preparation of advanced functional chiroptical materials. Herein, this Review discusses recent advances in chiral expression and morphology control in polymer dispersion systems, particularly the comparison between traditional post‐polymerization self‐assembly and in situ PISA strategies, to predict and advance chirality control in polymers. [ABSTRACT FROM AUTHOR]

While controlling the chirality and modulating the helicity is a challenging task, it attracts great research interest for gaining a better understanding of the origin of chirality in nature. Herein, structurally similar azobenzene (Azo) vinyl monomers were designed in which the alkyl chains comprised the chiral stereocenter with different achiral tail lengths. Combining the synchronous polymerization, supramolecular stacking and self‐assembly, the multiple chiroptical inversion of the Azo‐polymer supramolecular assemblies can be modulated by the tail length and DP of Azo blocks during in situ polymerization. The DP‐, UV light‐, temperature‐, aging time‐dependent chiroptical properties and liquid‐crystalline (LC) characterization indicated that the amorphous‐to‐LC phase transition and biphasic LC interconversion allow the transcription of intra‐chain π–π stacking, inter‐chain H‐ and J‐aggregation, thereby controlling the dynamic multiple reversal of supramolecular chirality. [ABSTRACT FROM AUTHOR]

Supramolecular chirality and its complete self‐recovery ability are highly mystical in nature and biological systems, which remains a major challenge today. Herein, we demonstrate that partially cross‐linked azobenzene (Azo) units can be employed as the potential chiral trigger to fully heal the destroyed helical superstructure in achiral nematic polymer system. Combining the self‐assembly of Azo units and terminal hydroxyl groups in polymer side chains allows the vapor‐induced chiral nematic phase and covalent fixation of the superstructure via acetal reaction. The induced helical structure of Azo units can be stored by inter‐chain cross‐linking, even after removal of the chiral source. Most interestingly, the stored chiral information can trigger perfect chiral self‐recovery (CSR) behavior after being destroyed by UV light, heat, and solvents. The results pave a new way for producing novel chiroptical materials with reversible chirality from achiral sources. [ABSTRACT FROM AUTHOR]

Hierarchical supramolecular chiral liquid‐crystalline (LC) polymer assemblies are challenging to construct in situ in a controlled manner. Now, polymerization‐induced chiral self‐assembly (PICSA) is reported. Hierarchical supramolecular chiral azobenzene‐containing block copolymer (Azo‐BCP) assemblies were constructed with π–π stacking interactions occurring in the layered structure of Azo smectic phases. The evolution of chirality from terminal alkyl chain to Azo mesogen building blocks and further induction of supramolecular chirality in LC BCP assemblies during PICSA is achieved. Morphologies such as spheres, worms, helical fibers, lamellae, and vesicles were observed. The morphological transition had a crucial effect on the chiral expression of Azo‐BCP assemblies. The supramolecular chirality of Azo‐BCP assemblies destroyed by 365 nm UV irradiation can be recovered by heating–cooling treatment; this dynamic reversible achiral–chiral switching can be repeated at least five times. [ABSTRACT FROM AUTHOR]

Keywords: Dynamic Crosslinking; Fixation and Regulation; Pattern-Embedded Storage; Supramolecular ChiralitySupramolecular Chemistry. In their Communication (e202312259), Tengfei Miao, Wei Zhang et al. report the simultaneous chiral fixation and regulation of chiral superstructures endowed by dynamic covalent bonds, providing access to novel pattern‐embedded storage materials...By Yuquan Guo; Xiaoxiao Cheng; Zixiang He; Zhenyang Zhou; Tengfei Miao and Wei ZhangReported by Author; Author; Author; Author; Author; Author [Extracted from the article]

The chiral substances from bottom to top are neutrons, molecules, oligomers, proteins, sugars, and macroscopic helical vines. Keywords: chirality; polymer dispersions; polymers; self-assembly; supramolecular chemistry EN chirality polymer dispersions polymers self-assembly supramolecular chemistry 1 1 1 05/27/22 20220501 NES 220501 B The cover feature image shows b that chirality is ubiquitous and can be observed at various hierarchical levels in nature. Chirality, polymer dispersions, polymers, self-assembly, supramolecular chemistry. [Extracted from the article]

Flexible construction of permanently stored supramolecular chirality with stimulus-responsiveness remains a big challenge. Herein, we describe an efficient method to realize the transfer and storage of chirality in intrinsically achiral films of a side-chain polymeric liquid crystal system by combining chiral doping and cross-linking strategy. Even the helical structure was destroyed by UV light irradiation, the memorized chiral information in the covalent network enabled complete self-recovery of the original chiral superstructure. These results allowed the building of a novel chiroptical switch without any additional chiral source in multiple types of liquid crystal polymers, which may be one of the competitive candidates for use in stimulus-responsive chiro-optical devices. [ABSTRACT FROM AUTHOR]

Recently, the design of novel supramolecular chiral materials has received a great deal of attention due to rapid developments in the fields of supramolecular chemistry and molecular self-assembly. Supramolecular chirality has been widely introduced to polymers containing photoresponsive azobenzene groups. On the one hand, supramolecular chiral structures of azobenzene-containing polymers (Azo-polymers) can be produced by nonsymmetric arrangement of Azo units through noncovalent interactions. On the other hand, the reversibility of the photoisomerization also allows for the control of the supramolecular organization of the Azo moieties within polymer structures. The construction of supramolecular chirality in Azo-polymeric self-assembled system is highly important for further developments in this field from both academic and practical points of view. The postpolymerization self-assembly strategy is one of the traditional strategies for mainly constructing supramolecular chirality in Azo-polymers. The in situ supramolecular self-assembly mediated by polymerization-induced self-assembly (PISA) is a facile one-pot approach for the construction of well-defined supramolecular chirality during polymerization process. In this review, we focus on a discussion of supramolecular chirality of Azo-polymer systems constructed by traditional postpolymerization self-assembly and PISA-mediated in situ supramolecular self-assembly. Furthermore, we will also summarize the basic concepts, seminal studies, recent trends, and perspectives in the constructions and applications of supramolecular chirality based on Azo-polymers with the hope to advance the development of supramolecular chirality in chemistry. [ABSTRACT FROM AUTHOR]