From Helices to Crystals: Multiscale Representation of Chirality in Double-Helix Structures

Macroscopic Gold Cluster Helical Tendrils

Handedness-controllable macroscopic helices are needed for understanding the chirality transfer through scales and design of high-performance devices. Bottom-up self-assembly rarely affords macroscopic helical superstructures because of accumulating disorder that is difficult to avoid during hierarchical self-assembly. Here, we demonstrate that tetragold Au4 clusters can assemble into macroscopic helices at the centimeter scale. Halogen-bond induces hierarchical self-assembly from nanotubes to aslant stacked nanotubes and finally to macrohelices. Sacrificial template synthesis via solvent-corrosion sufficiently removes the embedded 1,3,5-trifluoro-2,4,6-triiodobenzene to produce helical skeletons. Homochiral macroscopic tendrils are controllably synthesized by chiral halogen bonding donors, allowing high-fidelity chiral amplification. This work contributes to the development of macroscopic helical superstructures by hierarchical assembly.

Ultrahigh Energy Storage of Twisted Structures in Supramolecular Polymers

Polymer dielectrics possess outstanding advantages for high-power energy storage applications such as high breakdown strength (Eb) and efficiency (η), while both of them decrease rapidly at elevated temperatures. Although several strategies have been evaluated to enhance Eb and heat resistance, the discharged energy density (Ud) is still limited by the planar conjugated structure. In this study, a novel approach to manipulate polymer morphology is introduced, thereby influencing dielectric properties. A range of polyurea (PU)-based polymers are predicted from different structural unit combinations by machine learning and synthesized two representative polymers with high dielectric constants (K) and thermal stability. These polymers are combined with PI to form a twisted polymer via hydrogen bonding interactions (HNP). Both experimental results and computational simulations demonstrate the twisted structure disrupts the conjugated structure to widen the bandgap and increase dipole moment through the twisting of polar groups, leading to simultaneous improvements in both K and Eb. Consequently, HNP-20% achieves an ultrahigh Ud of 6.42 J cm-3 with an efficiency exceeding 90% at 200 °C. This work opens a new avenue to scalable high Ud all-polymer dielectric for high-temperature applications.

Stimulating Chiral Selective Expression of Room Temperature Phosphorescence for Chirality Recognition

Chiral recognition is crucial for applications in chiral purity assessment and biomedical fields. However, achieving chiral recognition through visible room temperature phosphorescence remains challenging. Here, two chiral molecules, designated as host and guest are synthesized, which possess similar structural configurations. A viable strategy involving a chiral configuration-dependent energy transfer process to enable selective phosphorescence expression is proposed, thereby enabling chiral recognition in a host-guest doping system. The chiral and structural similarity between host and guest facilitates efficient Dexter energy transfer due to the reduced spatial distance between the molecules. This mechanism significantly enhances the intensity of red phosphorescence from the guest molecule, characterized by an emission peak at 612 nm and a prolonged lifetime of 32.7 ms. This work elucidates the mechanism of chiral-dependent energy transfer, demonstrating its potential for selectively expressing phosphorescence in chiral recognition.

Hierarchical assembly of Ag40 nanowheel ranging from building blocks to diverse superstructure regulation

Achieving precise and controllable hierarchical self-assembly of functional nanoclusters within crystal lattices to create distinct architectures is of immense significance, yet it creates considerable challenges. Here we successfully synthesized a silver nanowheel Ag40, along with its optically pure enantiomers S-/R-Ag40. Each species possesses an internal nanospace and exhibits host-guest interactions. These structures are constructed from primary building blocks (Ag9). By manipulating the surface anions and guest molecules, the nanowheels function as secondary building blocks, spontaneously organizing into complex double- and triple-helical crystalline superstructures or one-dimensional chains {Ag41}n through conformational matching and diverse noncovalent interactions. Moreover, we demonstrate that the water-mediated complex specifically assembled with uridine monophosphate nucleotides, resulting in chiral assemblies of Ag40 that exhibit chiroptical activity for specific recognition. Our findings provide insights into the efficient construction of assemblies with hollow frameworks and propose strategies for superstructure engineering by manipulating surface motifs.

Macroscopic homochiral helicoids self-assembled via screw dislocations

Chirality is a fundamental property in nature and is widely observed at hierarchical scales from subatomic, molecular, supramolecular to macroscopic and even galaxy. However, the transmission of chirality across different length scales and the expression of homochiral nano/microstructures remain challenging. Herein, we report the formation of macroscopic homochiral helicoids with ten micrometers from enantiomeric pyromellitic diimide-based molecular triangle (PMDI-Δ) and achiral pyrene via a screw dislocation-driven co-self-assembly. Chiral transfer and expression from molecular and supramolecular levels, to the macroscopic helicoids, is continuous and follows the molecular chirality of PMDI-Δ. Furthermore, the screw dislocation and chirality transfer lead to a unidirectional curvature of the helicoids, which exhibit excellent circularly polarized luminescence with large |glum| values up to 0.05. Our results demonstrate the formation of a homochiral macroscopic organic helicoid and function emergence from small molecules via screw dislocations, which deepens our understanding of chiral transfer and expression across different length scales.

Magneto-optical Properties of Chiral Co2Ln and Co3Ln2 (Ln = Dy and Er) Clusters

A series of chiral heterometallic Ln-Co clusters, denoted as Co2Ln and Co3Ln2 (Ln = Dy and Er), were synthesized by reacting the chiral chelating ligand (R/S)-2-(1-hydroxyethyl)pyridine (Hmpm), CoAc2·4H2O, and Ln(NO3)3·6H2O. Co2Ln and Co3Ln2 exhibit perfect mirror images in circular dichroism within the 320-700 nm range. Notably, the Co2Er and Co3Er2 clusters display pronounced magnetic circular dichroism (MCD) responses of the hypersensitive f-f transitions 4I15/2-4G11/2 at 375 nm and 4I15/2-2H11/2 at 520 nm of ErIII ions. This study highlights the strong magneto-optical activity associated with hypersensitive f-f transitions in chiral 3d-4f magnetic clusters.

Observation of Chiral Channels in Helical Covalent Organic Frameworks

Unraveling the mechanism of chirality transfer across length scales is crucial to the rational development of functional materials with hierarchical chirality. The key obstacle is the lack of structural information, especially at the mesoscopic level. We report herein the structural identification of helical covalent organic frameworks (heliCOFs) with hierarchical chirality, which integrate molecular chirality, channel chirality, and morphology chirality into one crystalline entity. Specifically, benefiting from the highly ordered structure of heliCOFs, the existence of chiral channels at the mesoscopic level has been confirmed by electron crystallography, and the handedness of these chiral channels has been directly determined through the stereopair imaging technique. Accordingly, the chirality transfer in heliCOFs from microscopic to macroscopic levels could be rationalized with a layer-rotating model that has been supported by both crystal structure analysis and theoretical calculations. Observation of chiral channels in heliCOFs not only provides unprecedented data for the understanding of the chirality transfer process but also sheds new light on the rational construction of highly ordered polymeric materials with hierarchical chirality.

Directional Crystal Jumping Controlled by Chirality

Jumping crystals of racemic mixtures of asparagine monohydrate have been presented in this contribution to emphasize the key role of molecular chirality in governing the direction of macroscopic motions. When heated at the specific faces of the single crystals, a pair of enantiomorphs jump in opposite directions, which are further utilized for chiral resolution. The hydrogen-bonded networks between asparagine molecules in a specific direction provide oriented channels for the escape of water molecules during the dehydration, serving as a foundation for the directional crystal jumping. Our findings not only lay the foundation for the future creation of directed actuation systems based on dynamic crystals but shall also guide the efforts to reveal the correlation between chirality and motion across diverse realms of knowledge.

Double-Model Decay Strategy Integrating Persistent Photogenic Radicaloids with Dynamic Circularly Polarized Doublet Radiance and Triplet Afterglow

Organic phosphors integrating circularly polarized persistent luminescence (CPPL) across the visible range are widespread for applications in optical information encryption, bioimaging, and 3D display, but the pursuit of color-tunable CPPL in single-component organics remains a formidable task. Herein, via in situ photoimplanting radical ion pairing into axial chiral crystals, we present and elucidate an unprecedented double-module decay strategy to achieve a colorful CPPL through a combination of stable triplet emission from neutral diphosphine and doublet radiance from photogenic radicals in an exclusive crystalline framework. Owing to the photoactivation-dependent doublet radiance component and an inherent triplet phosphorescence in the asymmetric environment, the CPL vision can be regulated by altering the photoactivation and observation time window, allowing colorful glow tuning from blue and orange to delayed green emission. Mechanism studies clearly reveal that this asymmetric electron migration environment and hybrid n-π* and π-π* instincts are responsible for the afterglow and radical radiance at ambient conditions. Moreover, we demonstrate the applications of colorful CPPL for displays and encryption via manipulation of both excitation and observation times.

Coordination recognition of differential template units of lanthanide chiral chain

Coordination-driven self-assembly processes often produce remarkable structures. In particular, self-assembly processes mediated by chiral template units have provided research ideas for analyzing the formation of chiral macromolecules in living organisms. In this study, by regulating the proportion of reaction raw materials in the "one-pot" synthesis of lanthanide complexes, we constructed chiral template units with different coordination orientations. As a result, lanthanide chiral chains connected to different structures were obtained through the self-assembly process of coordination recognition. In particular, driven by coordination, chiral template units with codirectional coordination points (called cis configuration) coordinate solely with cis template units during the self-assembly process to obtain a one-dimensional (1D) chain R-1/S-1 with an "S"-shaped distribution. Moreover, chiral template units with reversed coordination sites (called trans configuration) and twisted chiral template units are connected solely to templates with the same configuration to form a 1D chain R-2/S-2 with an axial helix. A circular dichroism spectrum shows that R-1/S-1 and R-2/S-2 are two pairs of enantiomers. The controllable construction of these two differential 1D chains is of great significance for studying coordination recognition at the molecular level. To the best of our knowledge, this is the first study to construct a 1D lanthanide chain through the self-assembly process of coordination recognition. The assembly process of nucleotides to form a hierarchical structure is simulated. This work provides a vivid example of the controllable synthesis of lanthanide complexes with precise structures and offers a new perspective on the formation process of chiral macromolecules that simulates natural processes.