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The development of stimuli‐responsive circularly polarized luminescence (CPL) materials is quite attractive but challenging. Here, a pair of atomically precise enantiomers R/S‐Ag20 nanoclusters has been synthesized using chiral acid ligands. And then, stimuli‐responsive CPL materials were developed by assembling the chiral silver nanoclusters with an achiral bridging ligand. The atomically precise silver cluster‐assembled materials produce CPL with a dissymmetry factor (|glum|) of 1 × 10−3, through the high‐efficiency chiral induction process. More interestingly, the single CPL band at room temperature could quickly transform into highly separated dual CPL emissions at low temperature. This study provides a new strategy for the rational functionalization of chiral silver clusters in preparing cluster‐based CPL emitters and enriches the types of stimuli‐responsive CPL materials. [ABSTRACT FROM AUTHOR]

Constructing chiral supramolecular assembly and exploring the underlying mechanism are of great significance in promoting the development of circularly polarized luminescence (CPL)‐active materials. Herein, we report a solvation‐mediated self‐assembly from single‐crystals to helical nanofibers based on the first protic acyclic (methoxy)(amino)carbenes (pAMACs) AuI‐enantiomers driven by a synergetic aurophilic interactions and H‐bonds. Their aggregation‐dependent thermally activated delayed fluorescence properties with high quantum yields (ΦFL) up to 95 % were proved to be attributed to packing modes of Au⋅⋅⋅Au dimers with π‐stacking or one‐dimensional extended Au⋅⋅⋅Au chains. Via drop‐casting method, supramolecular P‐ or M‐helices were prepared. Detailed studies on the helices demonstrate that formations of extended helical Au⋅⋅⋅Au molecular chains amplify supramolecular chirality, leading to strong CPL with high dissymmetry factor (|glum|=0.030, ΦFL=67 %) and high CPL brightness (BCPL) of 4.87×10−3. Our findings bring new insights into the fabrication of helical structures to improve CPL performance by modifying aurophilic interactions. [ABSTRACT FROM AUTHOR]

Chiral Au nanoclusters have promising application prospects in chiral sensing, asymmetric catalysis, and chiroptics. However, enantiopure superatomic homogold clusters with crystallographic structures emitting bright circularly polarized luminescence (CPL) remain challenging. In this study, we designed chiral N‐heterocyclic carbenes (NHCs), and for the first time enantioselectively synthesized a pair of monovalent cationic superatomic Au13 clusters. This new enantiomeric pair of clusters has a quasi‐C2 symmetric core and exhibited CPL with an unprecedent solution‐state quantum yield (QY) of 61 % among those of the atomically precise Au nanoclusters. DFT calculations provided insights into the circular dichroism behavior, and revealed the origin of CPL from superatomic Au clusters. This work opens a new avenue for developing novel homochiral nanoclusters using chiral NHC ligands and provides fundamental understanding of the origin of the chiroptics of metal clusters. [ABSTRACT FROM AUTHOR]

Chiral metal‐organic frameworks (MOFs) are usually endowed by chiral linkers and/or guests. The strategy using chiral secondary building units in MOFs for solving the trade‐off of circularly polarized luminescence (CPL)‐active materials, high photoluminescence quantum yields (PLQYs) and high dissymmetry factors (|glum|) has not been demonstrated. This work directionally assembles predesigned chiral silver clusters with ACQ linkers through reticular chemistry. The nanoscale chirality of the cluster transmits through MOF's framework, where the linkers are arranged in a quasi‐parallel manner and are efficiently isolated and rigidified. Consequently, this backbone of chiral cluster‐based MOFs demonstrates superb CPL, high PLQYs of 50.3%, and |glum| of 1.2 × 10−2. Crystallographic analyses and DFT calculations show the quasi‐parallel arrangement manners of emitting linkers leading to a large angle between the electric and magnetic transition dipole moments, boosting CPL response. As compared, an ion‐pair‐direct assembly without interactions between linkers induces one‐ninth |glum| and one‐sixth PLQY values, further highlighting the merits of directional arrangement in reticular nets. In addition, a prototype CPL switching fabricated by a chiral framework is controlled through alternating ultraviolet and visible light. This work is expected to inspire the development of reticular chemistry for high‐performance chiroptical materials. [ABSTRACT FROM AUTHOR]

In this study, a pair of chiral copper(I) cluster‐assembled materials (R/S‐2) was prepared, exhibiting unique photo‐response characteristics with a concentration‐wavelength correlation property in DMSO solution. By the combination of R/S‐2 with a polymethyl methacrylate (PMMA) matrix, the first photo‐activated circularly polarized luminescence (CPL) film was developed, the CPL signal (glum=9×10−3) of which could be induced by UV light irradiation. Moreover, the film exhibited a reversible photo‐response and extremely good fatigue resistance. Mechanism study revealed that the photo‐response properties of the R/S‐2 solution and film are attributed to the aggregation‐induced emission (AIE) characteristics of R/S‐2 and a photo‐induced deoxygenation process. This study enriches the types of luminescent cluster‐assembled molecules and provides a new strategy for the construction of metal cluster‐based stimuli‐responsive composite materials. [ABSTRACT FROM AUTHOR]

Chiroptical hybrid organic–inorganic perovskites are emerging as a new class of promising materials with mirror optical signal responses for optoelectronic applications. However, chiroptical white‐emission materials have been scarcely unearthed. Herein, four pairs of hybrid lead(II) bromide perovskitoids were obtained, namely, (R)‐ and (S)‐(H2MPz)PbBr4 (R/S‐MPz=(R)‐(−)/(S)‐(+)‐2‐methylpiperazine) (1 and 2), (R)‐ and (S)‐(H2MPz)3Pb2Br10⋅2 DMAc (3 and 4), (R)‐ and (S)‐(H2MPz)PbBr4⋅0.5 MeCN (5 and 6) and (R)‐ and (S)‐(H2MPz)2Pb2Br8⋅DCM (7 and 8). Notably, they all exhibit ultrabroadband emission and chiroptical signals. Perovskitoids 3–6 even achieve white circularly polarized emission with a high dissymmetric factor (glum) (±3×10−3 for 3 and 4; ±8×10−3 for 5 and 6). This new type of hybrid perovskitoids will attract attention and find applications in chiroptical fields because of the extensively and easily tunable photophysical properties. [ABSTRACT FROM AUTHOR]

The weakly coordinated anionic nitrate ligands in a centrosymmetric Ag20 cluster are replaced in a stepwise manner by chiral amino acids and two achiral luminescent sulfonic‐group‐containing ligands while nearly maintaining the original silver(I) cage structure. This surface engineering enables the atomically precise Ag20 clusters to exhibit the high‐efficiency synergetic effects of chirality and fluorescence, producing rare circularly polarized luminescence among the metal clusters with a large dissymmetry factor of (|glum|) ≈ 5 × 10−3. This rational approach using joint functional ligands further opens a new avenue to diverse multifunctional metal clusters for promising applications. [ABSTRACT FROM AUTHOR]

Materials with circularly polarized luminescence (CPL) are especially fascinating due to the widespread potential applications in 3D displays, biological probes, security encoding, encrypted information transmission, and storage. Among these CPL‐active materials, the ones based on atomically precise coinage, namely, the metal coinage clusters, have attracted increasing attention due to their fascinating chiral structures and intriguing luminescence characteristics. Meanwhile, these clusters provide an ideal platform at the nanoscale for understanding the chiral transfer across the organic–inorganic interface. In this report, the recent progress in constructing enantiomerically pure chiral coinage metal clusters and the luminescent mechanism of coinage metal clusters in aggregated state are reviewed, respectively. Moreover, CPL‐active atomically precise coinage metal clusters and their design strategies are discussed in detail. Finally, challenges and opportunities for constructing atomically precise coinage metal clusters with excellent CPL properties are discussed. [ABSTRACT FROM AUTHOR]

Atomically precise enantiomeric metal clusters are scarce, and copper(I) alkynyl clusters with intense circularly polarized luminescence (CPL) responses have not been reported. A pair of chiral alkynyl ligands, (R/S)‐2‐diphenyl‐2‐hydroxylmethylpyrrolidine‐1‐propyne (abbreviated as R/S‐DPM) we successfully prepared and single crystals were characterized of optically pure enantiomeric pair of atomically‐precise copper(I) clusters, [Cu14(R/S‐DPM)8](PF6)6 (denoted as R/S‐Cu14), which feature bright red luminescence and CPL with a high luminescence anisotropy factor (glum). A dilute solution containing R/S‐Cu14 was nonluminescent and CPL inactive at room temperature. Crystallization‐ and aggregation‐induced emission (CIE and AIE, respectively) contribute to the triggering of the CPL of R/S‐Cu14 in the crystalline and aggregated states. Their AIE behavior and good biocompatibility indicated applications of these copper(I) clusters in cell imaging in HeLa and NG108‐15 cells. [ABSTRACT FROM AUTHOR]

A pair of propeller‐like chiral trinuclear CuI clusters (R/S‐Cu3) with unique photoinduced fluorescence enhancement were prepared. R/S‐Cu3 showed intense variable luminescence after UV light irradiation, which was attributed to the stepwise oxidation of ligand in the clusters. It exhibited typical aggregation‐induced emission (AIE) (αAIE=17.3). Mechanism studies showed that metal cluster‐centered (MCC) and triplet metal‐to‐ligand charge‐transfer (3MLCT) processes are the origin of the luminescence; the processes are regulated by a restriction of intramolecular motions mechanism in a different state. The chiral structure and AIE feature endow R/S‐Cu3 with remarkable circularly polarized luminescence (glum=2×10−2) in the aggregated state. It shows good capability for producing reactive oxygen species. This work enriches the kinds of atomically precise AIE clusters, gains insight into their luminescence mechanism, and offers the prospect of application in multifunctional materials. [ABSTRACT FROM AUTHOR]

Chiral assembly and asymmetric synthesis are critically important for the generation of chiral metal clusters with chiroptical activities. Here, a racemic mixture of [K(CH3OH)2(18‐crown‐6)]+[Cu5(StBu)6]− (1⋅CH3OH) in the chiral space group was prepared, in which the chiral red‐emissive anionic [Cu5(StBu)6]− cluster was arranged along a twofold screw axis. Interestingly, the release of the coordinated CH3OH of the cationic units turned the chiral 1⋅CH3OH crystal into a mesomeric crystal [K(18‐crown‐6)]+[Cu5(StBu)6]− (1), which has a centrosymmetric space group, by adding symmetry elements of glide and mirror planes through both disordered [Cu5(StBu)6]− units. The switchable chiral/achiral rearrangement of [Cu5(StBu)6]− clusters along with the capture/release of CH3OH were concomitant with an intense increase/decrease in luminescence. We also used cationic chiral amino alcohols to induce the chiral assembly of a pair of enantiomers, [d/l‐valinol(18‐crown‐6)]+[Cu5(StBu)6]− (d/l‐Cu5V), which display impressive circularly polarized luminescence (CPL) in contrast to the CPL‐silent racemic mixture of 1⋅CH3OH and mesomeric 1. [ABSTRACT FROM AUTHOR]