The continuous transmission and amplification of chirality is a fascinating feature in natural biological systems. However, achieving sequential transmission of circularly polarized luminescence (CPL) through multistep energy transfer remains a formidable challenge. Here, chiral N-heterocyclic carbene-protected Cu3 clusters (R/S-Cu3) were synthesized as lightharvesting antennas, self-assembling into blueemitting nanospheres with considerable CPL-active. Coumarin 6 (C-6), a green emitter, was introduced as the key relay baton for both chirality and energy transmission. We constructed chiral light-harvesting systems (LHSs) through the coassembly of R/S-Cu3, C-6, and red-emitting Nile Red (NiR), enabling efficient two-step energy transfer with a maximum efficiency (Phi ET, max) of 87.86%. Supramolecular engineering was employed to fabricate nanofiber bundles serving as film templates, which facilitated sequential CPL transmission from Cu3 to C-6 and subsequently to NiR. The sequential circularly polarized F & ouml;rster resonance energy transfer (CP-FRET) was verified via CPL spectral comparisons, resulting in distinct amplification of the dissymmetry factor. This work develops metal cluster-driven sequential CPL and energy transmission in chiral LHSs and provides in-depth insights into CP-FRET mechanism.

Rapid, reusable, and quantitative recognition of chiral acids and drugs remains challenging, as conventional covalent or host-guest strategies suffer from poor reversibility and limited adaptability. Here, atomically precise heterometallic nanoclusters undergo organic acid-induced coordination twisting and core symmetry breaking, dynamically modulating their coordination environment for enantiomeric resolution. Chiral amino acids stabilize cluster chirality, yielding enantiopure clusters matching the amino acid configuration. These clusters exhibit strong chiroptical responses, including circular dichroism (CD) and circularly polarized luminescence (CPL), enabling reliable quantification of enantiomeric excess (ee) across 20 chiral acids. Significantly, the system can be rationally regenerated and reused, enabling multiple cycles of consistent, quantitative chiral sensing. Mechanistic studies reveal that recognition arises from electrostatic preconcentration, followed by coordination and hydrogen bonding, which lock substrate configurations and transfer chiral information. Furthermore, threonine-modified chiral heterometallic clusters also enable enantioselective coordination-driven drug sensing, exemplified by ibuprofen recognition via ligand exchange, as unambiguously confirmed by single-crystal X-ray analysis. This work establishes a versatile coordination-driven platform for high-throughput, real-time, and quantitative enantioselective sensing, highlighting the potential of atomically precise clusters for chiral recognition and drug analysis.

Stimuli responsive phosphors with photoluminescence and thermoresponsive luminescence are intriguing for information encryption applications. Herein, two solvent-mediated, stimuli responsive phosphors based on phosphine-copper(I) iodide complexes 1 and 2 are reported. Complex 1 exhibited temperature- and excitation-wavelength-dependent dual-emission characteristics, displaying high energy (HE) and low energy (LE) bands with the quantum yield (QY) of 38.5% under 365 nm irradiation; but complex 2 exhibited no emission. The LE emission can be attributed to a triplet halide-to-metal charge transfer (3XMCT) and copper-centered 4d -> 3s, 3p transitions, whereas the HE emission originates from a triplet halide-to-ligand charge-transfer (3XLCT). Importantly, in complex 2, the strong C-H center dot center dot center dot Cl interaction in the supramolecular crystal lattice annihilated the sensitive cluster centered (3CC) excited state. Intriguingly, only the HE emission band of complex 2 can be successfully activated by high-energy excitation or changing the temperature. Nevertheless, the QY of complex 2 is 15.6% under 310 nm irradiation, which is smaller than that of complex 1 of 49.8%. This behavior was further confirmed by heating, where both complexes show HE emission. The reversible crystal transformation between complexes 1 and 2 was achieved. Furthermore, the reversible excitation-wavelength-dependent dual-emission and thermoresponsive properties make these phosphors suitable candidates for anti-counterfeiting and information encryption applications.

The construction of artificial light-harvesting systems (LHSs) with continuous chirality transfer is of great significance to deeply comprehend the hierarchical evolution in nature. Herein, the achiral C3-symmetric benzene-1,3,5-tricarboxamide (BTA) molecule functions as donor of LHSs motifs, where subnanometer-scale metal clusters (R/S-Ag6) are introduced as "Sergeants" to generate predominant handedness nanoribbons through chirality transfer. Importantly, these helical nanoribbons act as chirality and energy donors for the energy level-matching Ag6-cluster acceptors, enabling the fabrication of chirality-controlled LHSs that achieve amplified circularly polarized luminescence (CPL) of Ag6 clusters with a dissymmetry factor (|glum|) of 1 × 10-2. Notably, the CPL signals of R/S-Ag6 are further distinctly amplified with |glum| reaching 6 × 10-2 through chirality-matching and synergistic effect of R/S-1-phenylethanol. Furthermore, R/S-Cu6 clusters with near-infrared emission are employed as the second acceptor to construct relayed homochiral LHSs. Such LHSs program continuous chirality and energy transfers from BTA assemblies to Ag6 and then to AgxCu6-x alloy clusters, ultimately resulting in near-infrared CPL with |glum| of 5 × 10-2. This work provides valuable insight into the mechanisms of CPL transmission and amplification in cluster-driven chiral LHSs and opens potential application in chiroptical encryption.

Construction of artificial microscale helical superstructures holds great significance for understanding hierarchical evolution of chiral architectures in nature. However, fabricating microscale helical superstructures from metal clusters remains mysterious and challenging. Here, we achieved hierarchically assembled helical bowties with micrometer scale via electrostatic interaction-driven co-assembly of chiral Au4 clusters and trans-1,4-cyclohexanediamine. The size and conformation matching of chiral Au4 and trans-1,4-cyclohexanediamine compared to the other amines promotes continuous chirality transfer from Au4 to nanoplatelets and finally to helical microbowties that follows Au4 molecular chirality. We elucidated hierarchical evolution mechanism of morphology from nanoplatelets to microcake and to helical microbowties through gradual helical stacking and twisting of nanoplatelets. Furthermore, these helical microbowties exhibited excellent switchable photoluminescence and circularly polarized luminescence characteristics governed by dissociation and recombination of electrostatic interactions. This work demonstrates the formation of controllable metal cluster-based helical microbowties and deepens the understanding of chirality transfer and expression at microscale.

Metal halide perovskite light-emitting diodes (PeLEDs) are ideal for high-resolution displays due to their tunable emission, narrow spectra, and low-cost processing. Colloidal FAPbBr3 perovskite quantum dots (PeQDs) enhance radiative recombination, making them efficient for pure-green PeLEDs. However, their low stability and surface defects limit their practical application. Here, we address these challenges by proposing an in situ surface repair strategy using benzhydroxamic acid (BHA) as a modifier. We demonstrated that BHA can coordinate with Pb2+ ions and form hydrogen bonds with FA+ and halide ions, effectively reducing nonradiative recombination and maintaining the integrity of the PeQDs. High-quality FAPbBr3 PeQDs with a photoluminescence quantum yield (PLQY) of up to 92.5% were achieved, leading to pure-green PeLEDs with an external quantum efficiency (EQE) of 24.8% and a maximum luminance of 40,231 cd m-2, providing a feasible and promising perspective for advanced solid-state lighting and displays.

Constructing novel photoswitch silver-chalco-genolate cluster-based metal-organic framewrorks (SCC-MOFs) presents a considerable challenge owing to their instability and limited stimulation-responsive properties. Herein, a novel photochromic SCC-MOF (Ag12-BMPTC) was designed and synthesized using a diarylethene ligand and an SCC. Ag12-BMPTC exhibits superior reversible photo-responsive characteristics under light irradiation (365 and 500 nm). This photoswitching behavior enables its potential applications in information encryption and chirality switches, making it as the first example of such capabilities in photochromic SCC-MOFs. This study not only expands the range of SCC-MOFs but also proposes a new strategy for designing and synthesizing novel photochromic materials.

The construction of effective artificial chiral light -harvesting systems ( CLHSs) is significantly important as it provides insights into the hierarchical levels of chirality evolution in natural systems. Herein, we devised pairs of chiral blue emitters, S- / R- binaphthalene dioxygenN- octadecamidephthalimide ( S- / R- BPOA), which function as donors of chirality and light absorbers. S- / R- BPOA co -assembled with enantiomers of atomically precise yellow -emitting subnanometer-scale Ag 6 clusters to fabricate CLHSs. Within these hybrid CLHSs, we successfully resolved enantioselective chirality/energy transfer that was dependent on the handedness of the components. This promoted the efficient circularly polarized energy transfer in chirality-compatible ensembles, resulting in a remarkable amplification of circularly polarized luminescence (CPL) in the ultrasmall silver cluster. The achieved dissymmetry factor ( g lum ) reached an impressive value of 1.54 3 10 - 2 , and white -light CPL with chromaticity coordinates of (0.32, 0.33) was obtained. Furthermore, the customizable fluorescence and CPL in these CLHSs bestow them with potential application possibilities in information storage and encryption.

Artificial systems for sequential chirality transmission/amplification and energy relay are perpetual topics that entail learning from nature. However, engineering chiral light-harvesting supramolecular systems remains a challenge. Here, we developed new chiral light-harvesting systems with a sequential Förster resonance energy transfer process where a designed blue-violet-emitting BINOL (1,1'-Bi-2-naphthol) compound, BINOL-di-octadecylamide (BDA), functions as an initiator of chirality and light absorbance, a new green-emitting hexagonal tetraphenylethene-based macrocycle (TPEM) with aggregation-induced emission serves as a conveyor, and Nile red (NiR) or/and a near-infrared dye, tetraphenylethene (TPE)-based benzoselenodiazole (TPESe), are the terminal acceptors. Benefiting from the close contact and large optical overlap between donors and acceptors at each level, triad and tetrad relaying systems sequentially and efficiently furnish chirality transmission/amplification and energy transfer along the cascaded line BDA-TPEM-NiR (or/and TPESe), leading to bright customized-color circularly polarized luminescence (CPL) and bright white-light-emitting CPL (CIE coordinates: 0.33, 0.34) with an amplified dissymmetry factor (glum) of 3.5 × 10-2 over a wide wavelength range. This work provides a new direction for the construction of chiral light-harvesting systems for a broad range of applications in chiroptical physics and chemistry.

A new tetraphenylethylene-cyclodextrin (TPE-CD) conjugate with a linkage composed of long triethylene glycol chain and triazole ring on the CD rim has been designed and synthesized. The TPE-CD conjugate exists in a stretched form in DMSO and enhances its fluorescence after addition of a small amount of water due to aggregation-induced emission (AIE) effect. However, in the presence of a large amount of water, the TPE unit will enter the cyclodextrin cavity to form a folded self-inclusion compound. In the self-inclusion compound, not only nitrogen-containing pseudo-crown ether is formed but also arouses photo-induced electron transfer (PET) process from nitrogen atoms of triazole ring to TPE unit and quenches the fluorescence although more aggregation occurs in more water. This is the first finding that TPE-macrocycle conjugate can form pseudo-crown ether and has both the AIE phenomenon and the PET effect. Interestingly, only mercury ion arouses the fluorescence recover of the self-inclusion compound by entering the pseudo-crown ether cavity and blocking the PET process by binding to the nitrogen atoms, while other tested metal ions almost have no effect on the fluorescence. Therefore, the TPE-CD conjugate can be used for the highly selective fluorescence "Turn-On" detection of Hg2+.

Main observation and conclusion One pair of new enantiomers of helical tetraphenylethylene (TPE) tetracycle tetradodecylurea, which show aggregation‐induced emission (AIE) enhancement effect, were synthesized by attaching four dodecyl chains to a helical TPE tetracycle tetramine through urea linkage. These two TPE helicates bearing long alkyl chains could display strong circular dichroism (CD) and circularly polarized luminescence (CPL) signals not only in solution but also in solid state. Due to strong van der Waals interactions between the alkyl chains, the absolute dissymmetrical factor | g lum | was up to 6.6 × 10 ‐3 , which was 2—3 fold larger than that of the helical TPE tetracycle tetramine (TPETA) without long alkyl chains in solution. Due to bearing hydrophilic urea units and hydrophobic long dodecyl chains, the helical TPE tetracycle could form chiral Langmuir‐Blodgett (LB) monolayers at air/water interface and showed a strong and stable second harmonic generation (SHG) chiral signals. The degree of chiral excess (DCE) for P‐isomer monolayer was up to ‐0.682 ± 0.0014. This is the first example to detect chirality at the air/water interface for chiral AIE molecules. It provides a new access to the application of chiral AIE compounds in nonlinear optical activity.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Due to immense potential in using as chemo/biosensors and solid emitters, aggregation-induced emission (AIE) phenomenon is attracting huge interest in scientific community. After endowed with chirality, the resultant chiral AIE luminogens (AIEgen), just like a tiger with added wings, can display more and stronger promising functionalities. Moreover, many classic luminophores can be transformed into AIEgens from notorious aggregation-caused quenching (ACQ) compounds as soon as they are attached with chiral groups. Compared with other chiral fluorescent receptors and chiral emitter, chiral AIEgens have displayed unique and outstanding advantages. Firstly, chiral AIEgen can differentiate two enantiomers of chiral analyte by 1.68 x 10(4) fold difference and get a chiral magnification up to 2.5 x 10(3) times due to aggregation. In addition, two enantiomers of up to 18 chiral carboxylic acids can be recognized just by using only one chiral AIEgen receptor and enantiomeric excess (ee) of chiral analytes at uM level can be measured. Furthermore, accurate ee analysis was carried out for the first time from fluorescence wavelength change rather than intensity change of the chiral AIEgen receptor. Therefore, the chiral AIEgens show unprecedentedly high selectivity, high sensitivity, high applicability, and high accuracy. Secondly, in the area of organic circularly polarized luminescence (CPL) materials, the CPL dissymmetry factor (g(lum)) of chiral AIEgen can get to 1.42 that is near to the theoretical value of 2, making a breakthrough progress while the vertical bar g(lum)vertical bar of previous organic luminophores is generally between 10(-5) and 10(-2). Furthermore, the highly efficient circularly polarized organic light-emitting diodes (CPOLEDs) are constructed for the first time by chiral AIEgens. Thirdly, chiral AIEgens enable novel display technology under different lighting conditions to be possible. More importantly, due to AIE effect, AIEgens are very beneficial for disclosing the mechanism of chiral transfer and magnification between molecules, which is thought to be the key for evolution of homochirality in natural world and preparation of chiral materials with hierarchical structures. For the above reason, chiral AIEgens have been brought to extensive attention and a large number of research works about them are reported. To take an overall view on chiral AIEgens and facilitate the development of chiral AIEgens, it is necessary to make a full review on the chiral AIEgens. This review covers the following contents: (1) construction of chiral AIEgens including propeller-like chiral AIEgens, chiral AIEgens with optically pure groups, polymer chiral AIEgens and supramolecular chiral AIEgen system; (2) chiral recognition and ee determination of chiral carboxylic acids, chiral amines, alpha-amino acids, and chiral neutral molecules by chiral AIEgens; (3) performance of chiral AIEgens in circular dichroism (CD), CPL and CPOLEDs; (4) other versatile application researches related to chiral AIEgens. (C) 2020 Elsevier B.V. All rights reserved.

The aggregation-induced emission (AIE) mechanism of restriction of double-bond rotation (RDBR) was utilized to design an excellent solid emitter and sensor for the first time. Thus, cis-tetraphenylethylene (TPE) macrocycle diammoniums were synthesized and bound to a DNA chain by its two ammonium arms. The formed TPE dicycle at the cis position restricted the rotation of the double bond in both the ground and excited states, resulting in AIE enhancement, chiroptical performance enhancement, and sensing enhancement.

Further assembly of helical self-assemblies is exploited to further boost the dissymmetry factor and obtain the largest magnification of circularly-polarized luminescence.

Planar molecules usually display aggregation-caused quenching (ACQ). Here, it was found that a completely planar organic compound, 5,7,12,14-tetraoxapentacene A-D-A triad with carbon-oxygen bonds, had no fluorescence in high polar solvents but emitted strong light in suspension and in solid state, showed typical ALE effect. One novel AIE mechanism was disclosed by molecular pacicing in crystal state. In addition, its exceptional AIE effect showed great potential applications in fluorescent thermometer and highly sensitive sensor for selective detection of nitrophenolic compounds. The detection limit for 2,4,6-trinitrophenol was low to 0.168 nM.

Hydrazones are recently attracting increasing interest because of their facile synthesis and high addressability, fatigue resistance, and modifiability as molecular switches. However, this new class of switches generally suffers from low conversion from E- to Z-configuration. Here, novel benzoylhydrazones were synthesized by condensation of 2-methoxynaphthaldhyde and benzoylhydrazine. In this hydrazone system, both sides of the imine double bond had large steric hindrance, so that the ( E)-isomer of the benzoylhydrazones was less stable and easily converted into the ( Z)-isomer even without an intramolecular hydrogen bond. Up to 99% conversion efficiency and 89% quantum yield were obtained, in addition to excellent addressability and high fatigue resistance. Outstandingly, the crystal structure of one ( Z)-isomer disclosed no intermolecular hydrogen bonds between the molecules of the ( Z)-isomer but strong and sequential hydrogen bonds between those of the ( E)-isomer. Therefore, the ( E)-isomer was less soluble in solvents than the ( Z)-isomer. This molecular switch system could be easily modified by both hydrophilic pentaethylene glycol chains and hydrophobic octyl chains. Under light irradiation, the resultant amphiphilic acylhydrazone could be transferred from ( E)-isomer to ( Z)-isomer in more than 90% yield even in water after light irradiation. Meanwhile, the self-assembled big nanospheres could rearrange into much smaller vesicles because of the solubility difference of ( Z)- and ( E)-isomers. After the anticancer drug procarbazine was loaded by this kind of acylhydrazone in water, it could be released by light irradiation, showing potential application in photocontrollable drug release.

TPE dicycle tetracholesterol aggregates into nano-tubes and emits strong CPL light, whereas its suspension emits inverse CPL one. In contrast, TPE tetracholesterol without cycle self-assembles into nano-noodles and shows very weak CPL emission.

Non-coplanar triple-hydrogen-bond arrays are connected as telechelic groups to alkyl chains and their properties as AA/BB type supramolecular polymers are examined. Viscosity studies at three temperatures are used to study the ring-chain equilibrium and determine the critical concentrations where polymer chains are formed. It is observed that neither the temperature range studied nor the alkyl chain length of one component significantly affect the polymerization properties in this system.