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Coinage metal (Au, Ag, Cu) cluster and polyoxometalate (POM) cluster represent two types of subnanometer "artificial atoms" with significant potential in catalysis, sensing, and nanomedicine. While composite clusters combining Ag/Cu clusters with POM have achieved considerable success, the assembly of gold clusters with POM is still lagging. Herein, we first designedly synthesized two cluster structural units: an Au 3 O cluster stabilized by diverse N-heterocyclic carbene (NHC) ligands and an amine-terminated POM linker. The subsequent reaction involved amine substitution in the POM linker for the central O atom in the Au 3 O cluster, resulting in the first ternary composite cluster-a POM cluster sandwiched by two Au clusters protected by NHCs. Single-crystal X-ray diffraction and other characteristic methods characterized their atomically precise structures. Furthermore, altering the NHC ligands decreased the number of gold atoms in the sandwich structures, accompanying the different protonated degrees of amine ligand in the terminal end of the POM linker. These composite clusters showed excellent performances in catalytic H 2 O 2 conversion through the synergistic effect between gold clusters and POM clusters. This work opens a new avenue to functional composite metal clusters and would promote their enhanced catalysis applications through intercluster synergistic interactions within composite systems., (© 2024 Wiley-VCH GmbH.)

Precise control over the organic composition is crucial for tailoring the distinctive structures and properties of hybrid metal halides. However, this approach is seldom utilized to develop materials that exhibit stimuli-responsive circularly polarized luminescence (CPL). Herein, we present the synthesis and characterization of enantiomeric hybrid zinc bromides: biprotonated ((R/S)-C 12 H 16 N 2 )ZnBr 4 ((R/S-LH2)ZnBr 4 ) and monoprotonated ((R/S)-C 12 H 15 N 2 ) 2 ZnBr 4 ((R/S-LH1) 2 ZnBr 4 ), derived from the chiral organic amine (R/S)-2,3,4,9-Tetrahydro-1H-carbazol-3-amine ((R/S)-C 12 H 14 N 2 ). These compounds showcase luminescent properties; the zero-dimensional biprotonated form emits green light at 505 nm, while the monoprotonated form, with a pseudo-layered structure, displays red luminescence at 599 and 649 nm. Remarkably, the reversible local protonation-deprotonation behavior of the organic cations allows for exposure to polar solvents and heating to induce reversible structural and luminescent transformations between the two forms. Theoretical calculations reveal that the lower energy barrier associated with the deprotonation process within the pyrrole ring is responsible for the local protonation-deprotonation behavior observed. These enantiomorphic hybrid zinc bromides also exhibit switchable circular dichroism (CD) and CPL properties. Furthermore, their chloride counterparts were successfully obtained by adjusting the halogen ions. Importantly, the unique stimuli-responsive CPL characteristics position these hybrid zinc halides as promising candidates for applications in information storage, anti-counterfeiting, and information encryption., (© 2024 Wiley-VCH GmbH.)

Electrocatalytic nitrate reduction reaction (NO 3 RR) is a process that requires the participation of eight electrons and nine protons. The regulation of active hydrogen (H*) supply and a deep understanding of related processes are necessary for improving the ammonia yield rate and Faradaic efficiency (FE). Herein, we synthesized a series of atomically precise copper-halide clusters Cu 2 X 2 (BINAP) 2 (X=Cl, Br, I), among which the Cu 2 Cl 2 (BINAP) 2 cluster shows the optimal ammonia FE of 94.0 % and an ammonia yield rate of 373 μmol h -1  cm -2 . In situ experiments and theoretical calculations reveal that halogen atoms, especially Cl in Cu 2 Cl 2 (BIANP) 2 , can significantly affect the distance of alkali metal-ionized water on the catalyst surface, which can promote the water dissociation to enhance the localized H* enrichment for the continues hydrogenation of nitrate to ammonia. This work explains the role of H* in the hydrogenation process of NO 3 RR and the importance of localized H* enrichment strategy for improving the FEs., (© 2024 Wiley-VCH GmbH.)

The dual emission (DE) characteristics of atomically precise copper nanoclusters (Cu NCs) are of significant theoretical and practical interest. Despite this, the underlying mechanism driving DE in Cu NCs remains elusive, primarily due to the complexities of excited state processes. Herein, a novel [Cu 4 (PPh 3 ) 4 (C≡C-p-NH 2 C 6 H 4 ) 3 ]PF 6 (Cu 4 ) NC, shielded by alkynyl and exhibiting DE, was synthesized. Hydrostatic pressure was applied to Cu 4 , for the first time, to investigate the mechanism of DE. With increasing pressure, the higher-energy emission peak of Cu 4 gradually disappeared, leaving the lower-energy emission peak as the dominant emission. Additionally, the Cu 4 crystal exhibited notable piezochromism transitioning from cyan to orange. Angle-dispersive synchrotron X-ray diffraction results revealed that the reduced inter-cluster distances under pressure brought the peripheral ligands closer, leading to the formation of new C-H⋅⋅⋅N and N-H⋅⋅⋅N hydrogen bonds in Cu 4 . It is proposed that these strengthened hydrogen bond interactions limit the ligands' vibration, resulting in the vanishing of the higher-energy peak. In situ high-pressure Raman and vibrationally resolved emission spectra demonstrated that the benzene ring C=C stretching vibration is the structural source of the DE in Cu 4 ., (© 2024 Wiley-VCH GmbH.)

Crystalline frameworks represent a cutting-edge frontier in material science, and recently, there has been a surge of interest in energetic crystalline frameworks. However, the well-established porosity often leads to diminished output energy, necessitating a novel approach for performance enhancement. Thiol-yne coupling, a versatile metal-free click reaction, has been underutilized in crystalline frameworks. As a proof of concept, we herein demonstrate the potential of this approach by introducing the energy-rich, size-matched, and reductive 1,2-dicarbadodecaborane-1-thiol (CB-SH) into an acetylene-functionalized framework, Zn(AIm) 2 , via thiol-yne click reaction. This innovative decoration strategy resulted in a remarkable 46.6 % increase in energy density, a six-fold reduction in ignition delay time (4 ms) with red fuming nitric acid as the oxidizer, and impressive enhancement of stability. Density functional theory calculations were employed to elucidate the mechanism by which CB-SH promotes hypergolic ignition. The thiol-yne click modification strategy presented here permits engineering of crystalline frameworks for the design of advanced energetic materials., (© 2024 Wiley‐VCH GmbH.)

The specific states of aggregation of metal atoms in sub-nanometer-sized gold clusters are related to the different quantum confinement volumes of electrons, leading to novel optical and electronic properties. These volumes can be tuned by changing the relative positions of the gold atoms to generate isomers. Studying the isomeric gold core and the electron coupling between the basic units is fundamentally important for nanoelectronic devices and luminescence; however, appropriate cases are lacking. In this study, the structure of the first staggered di-superatomic Au 25 -S was solved using single-crystal X-ray diffraction. The optical properties of Au 25 -S were studied by comparing with eclipsed Au 25 -E. From Au 25 -E to Au 25 -S, changes in the electronic structures occurred, resulting in significantly different optical absorptions originating from the coupling between the two Au 13 modules. Au 25 -S shows a longer electron decay lifetime of 307.7 ps before populating the lowest triplet emissive state, compared to 1.29 ps for Au 25 -E. The experimental and theoretical results show that variations in the geometric isomerism lead to distinct photophysical processes owing to isomerism-dependent electronic coupling. This study offers new insights into the connection between the geometric isomerism of nanosized building blocks and the optical properties of their assemblies, opening new possibilities for constructing function-specific nanomaterials., (© 2024 Wiley-VCH GmbH.)

The propulsion of photocatalytic hydrogen (H 2 ) production is limited by the rational design and regulation of catalysts with precise structures and excellent activities. In this work, the [MoOS 3 ] 2- unit is introduced into the Cu I clusters to form a series of atomically-precise Mo VI -Cu I bimetallic clusters of [Cu 6 (MoOS 3 ) 2 (C 6 H 5 (CH 2 )S) 2 (P(C 6 H 4 -R) 3 ) 4 ] ⋅ xCH 3 CN (R=H, CH 3 , or F), which show high photocatalytic H 2 evolution activities and excellent stability. By electron push-pull effects of the surface ligand, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of these Mo VI -Cu I clusters can be finely tuned, promoting the resultant visible-light-driven H 2 evolution performance. Furthermore, Mo VI -Cu I clusters loaded onto the surface of magnetic Fe 3 O 4 carriers significantly reduced the loss of catalysts in the collection process, efficiently addressing the recycling issues of such small cluster-based catalyst. This work not only highlights a competitively universal approach on the design of high-efficiency cluster photocatalysts for energy conversion, but also makes it feasible to manipulate the catalytic performance of clusters through a rational substituent strategy., (© 2023 Wiley-VCH GmbH.)

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 Au 13 clusters. This new enantiomeric pair of clusters has a quasi-C 2 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., (© 2023 Wiley-VCH GmbH.)

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)-(H 2 MPz)PbBr 4 (R/S-MPz=(R)-(-)/(S)-(+)-2-methylpiperazine) (1 and 2), (R)- and (S)-(H 2 MPz) 3 Pb 2 Br 10 ⋅2 DMAc (3 and 4), (R)- and (S)-(H 2 MPz)PbBr 4 ⋅0.5 MeCN (5 and 6) and (R)- and (S)-(H 2 MPz) 2 Pb 2 Br 8 ⋅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 (g lum ) (±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., (© 2022 Wiley-VCH GmbH.)

In contrast to the wealth of asymmetric transformations for generating central chirality from alkyl radicals, the enantiocontrol over the allenyl radicals for forging axial chirality represents an uncharted domain. The challenge arises from the unique elongated linear configuration of the allenyl radicals that necessitates the stereo-differentiation of remote motifs away from the radical reaction site. We herein describe a copper-catalyzed asymmetric radical 1,4-carboalkynylation of 1,3-enynes via the coupling of allenyl radicals with terminal alkynes, providing diverse synthetically challenging tetrasubstituted chiral allenes. A chiral N,N,P-ligand is crucial for both the reaction initiation and the enantiocontrol over the highly reactive allenyl radicals. The reaction features a broad substrate scope, covering a variety of (hetero)aryl and alkyl alkynes and 1,3-enynes as well as radical precursors with excellent functional group tolerance., (© 2020 Wiley-VCH GmbH.)

We describe a photoinduced copper-catalyzed asymmetric radical decarboxylative alkynylation of bench-stable N-hydroxyphthalimide(NHP)-type esters of racemic alkyl carboxylic acids with terminal alkynes, which provides a flexible platform for the construction of chiral C(sp 3 )-C(sp) bonds. Critical to the success of this process are not only the use of the copper catalyst as a dual photo- and cross-coupling catalyst but also tuning of the NHP-type esters to inhibit the facile homodimerization of the alkyl radical and terminal alkyne, respectively. Owing to the use of stable and easily available NHP-type esters, the reaction features a broader substrate scope compared with reactions using the alkyl halide counterparts, covering (hetero)benzyl-, allyl-, and aminocarbonyl-substituted carboxylic acid derivatives, and (hetero)aryl and alkyl as well as silyl alkynes, thus providing a vital complementary approach to the previously reported method., (© 2020 Wiley-VCH GmbH.)

Luminescent metal clusters show promise for applications in imaging and sensing. However, promoting emission from metal clusters at room temperature is a challenging task owing to the lack of an efficient approach to suppress the nonradiative decay process in metal cores. We report herein that the addition of a silver atom into a metal interstice of the radarlike thiolated silver cluster [Ag 27 (S t Bu) 14 (S) 2 (CF 3 COO) 9 (DMAc) 4 ]⋅DMAc (NC1, DMAc=dimethylacetamide), which is non-emissive under ambient conditions, produced another silver cluster [Ag 28 (AdmS) 14 (S) 2 (CF 3 COO) 10 (H 2 O) 4 ] (NC2) that displayed bright green room-temperature photoluminescence aided by the new ligand 1-adamantanethiol (AdmSH). The 28th Ag atom, which hardly affects the geometrical and electronic structures of the Ag-S skeleton, triggered the emission of green light as a result of the rigidity of the cluster structure., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

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, [Cu 14 (R/S-DPM) 8 ](PF 6 ) 6 (denoted as R/S-Cu 14 ), which feature bright red luminescence and CPL with a high luminescence anisotropy factor (g lum ). A dilute solution containing R/S-Cu 14 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-Cu 14 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., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Chiral assembly and asymmetric synthesis are critically important for the generation of chiral metal clusters with chiroptical activities. Here, a racemic mixture of [K(CH 3 OH) 2 (18-crown-6)] + [Cu 5 (S t Bu) 6 ] - (1⋅CH 3 OH) in the chiral space group was prepared, in which the chiral red-emissive anionic [Cu 5 (S t Bu) 6 ] - cluster was arranged along a twofold screw axis. Interestingly, the release of the coordinated CH 3 OH of the cationic units turned the chiral 1⋅CH 3 OH crystal into a mesomeric crystal [K(18-crown-6)] + [Cu 5 (S t Bu) 6 ] - (1), which has a centrosymmetric space group, by adding symmetry elements of glide and mirror planes through both disordered [Cu 5 (S t Bu) 6 ] - units. The switchable chiral/achiral rearrangement of [Cu 5 (S t Bu) 6 ] - clusters along with the capture/release of CH 3 OH 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)] + [Cu 5 (S t Bu) 6 ] - (d/l-Cu 5V ), which display impressive circularly polarized luminescence (CPL) in contrast to the CPL-silent racemic mixture of 1⋅CH 3 OH and mesomeric 1., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Silver chalcogenolate cluster assembled materials (SCAMs) are a category of promising light-emitting materials the luminescence of which can be modulated by variation of their building blocks (cluster nodes and organic linkers). The transformation of a singly emissive [Ag 12 (SBu t ) 8 (CF 3 COO) 4 (bpy) 4 ] n (Ag 12 bpy, bpy=4,4'-bipyridine) into a dual-emissive [(Ag 12 (SBu t ) 6 (CF 3 COO) 6 (bpy) 3 )] n (Ag 12 bpy-2) via cluster-node isomerization, the critical importance of which was highlighted in dictating the photoluminescence properties of SCAMs. Moreover, the newly obtained Ag 12 bpy-2 served to construct visual thermochromic Ag 12 bpy-2/NH 2 by a mixed-linker synthesis, together with dichromatic core-shell Ag 12 bpy-2@Ag 12 bpy-NH 2 -2 via solvent-assisted linker exchange. This work provides insight into the significance of metal arrangement on physical properties of nanoclusters., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A copper-catalyzed asymmetric radical oxytrifluoromethylation of alkenyl oxime and Togni's reagent has been successfully developed, thereby providing straightforward access to CF 3 -containing isoxazolines bearing α-tertiary stereocenters with excellent yield and enantioselectivity. The key to success is the rational design of cinchona-alkaloid-based sulfonamides as neutral/anionic hybrid ligands to effectively control the stereochemistry in copper-catalyzed reactions involving free alkyl radical species. The utility of this method is illustrated by efficient transformation of the products into useful chiral CF 3 -containing 1,3-aminoalcohols., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A conceptually novel strategy with achiral pyridine as the ancillary ligand to stabilize high-valent copper species for the first asymmetric radical oxytrifluoromethylation of alkenes with alcohols under Cu I /phosphoric acid dual-catalysis has been developed. The transformation features mild reaction conditions, a remarkably broad substrate scope and excellent functional group tolerance, offering an efficient approach to a wide range of trifluoromethyl-substituted tetrahydrofurans bearing an α-tertiary stereocenter with excellent enantioselectivity. Mechanistic studies support the presumed role of the achiral pyridine as a coordinative ligand on copper metal to stabilize the key transient reaction species involved in the asymmetric induction process., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A crystalline coordination polymer (CP) photocatalyst (Cu-RSH) which combines redox-active copper centers with photoactive rhodamine-derived ligands remains stable in acid and basic solutions from pH 2 to 14, and efficiently catalyzes dihydrogen evolution at a maximum rate of 7.88 mmol g(-1)  h(-1) in the absence of a mediator and a co-catalyst. Cyclic voltammetry, control experiments, and DFT calculations established that copper nodes with open coordination sites and favorable redox potentials, aided by spatially ordered stacking of rhodamine-based linkers, account for the high catalytic performance of Cu-RSH. Emission quenching, time-resolved fluorescence decay, and transient photocurrent experiments disclosed the charge separation and transfer process in the catalytic system. The present study demonstrates the potential of crystalline copper CPs for the practical utilization of light., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)