Concentration- and Solvation-Induced Reversible Structural Transformation and Assembly of Polynuclear Gold(I) Sulfido Complexes

A Phosphorescent P/N/S Hybrid Ligand Stabilized Au2Cu Complex Selectively Senses Ammonia and Amines

Reaction of a P/N/S hybrid ligand dpppyatc (N,N-bis((diphenylphosphaneyl)methyl)-N-(pyridin-2-yl)-amino-thiocarbamide) with Au(tht)Cl (tht=tetrahydrothiophene) and [Cu(MeCN)4]BF4 afforded cluster complex [Au2Cu(dpppyatc)2](BF4)2Cl (1). Upon excitation at 480 nm, 1 emitted orange phosphorescence at 646 nm, which was red-shifted to ~698 nm selectively in the presence of ammonia or amine vapor. This chromic photoluminescent response toward ammonia was sensitive and reversible. Complex1 could detect ammonia in aqueous solution down to concentrations of 2 ppm (w/w).

Chemical Flexibility of Atomically Precise Metal Clusters

Ligand-protected metal clusters possess hybrid properties that seamlessly combine an inorganic core with an organic ligand shell, imparting them exceptional chemical flexibility and unlocking remarkable application potential in diverse fields. Leveraging chemical flexibility to expand the library of available materials and stimulate the development of new functionalities is becoming an increasingly pressing requirement. This Review focuses on the origin of chemical flexibility from the structural analysis, including intra-cluster bonding, inter-cluster interactions, cluster-environments interactions, metal-to-ligand ratios, and thermodynamic effects. In the introduction, we briefly outline the development of metal clusters and explain the differences and commonalities of M(I)/M(I/0) coinage metal clusters. Additionally, we distinguish the bonding characteristics of metal atoms in the inorganic core, which give rise to their distinct chemical flexibility. Section 2 delves into the structural analysis, bonding categories, and thermodynamic theories related to metal clusters. In the following sections 3 to 7, we primarily elucidate the mechanisms that trigger chemical flexibility, the dynamic processes in transformation, the resultant alterations in structure, and the ensuing modifications in physical-chemical properties. Section 8 presents the notable applications that have emerged from utilizing metal clusters and their assemblies. Finally, in section 9, we discuss future challenges and opportunities within this area.

Heterometallic AuI 6 AgI 6 Macrocyclic Cluster Templated by a Supramolecular Melamine Dimer

The application of supramolecular templates in aligning atomically precise heterometal arrays is important for pursuing functional materials. Herein, we report that a bilayered supramolecular tri-deprotonated melamine dimer functions as an effective template in the construction of a heterometallic gold(I)-silver(I) macrocyclic cluster [μ6 -(C3 N6 H3 )3- ]2 -AuI 6 AgI 6 . X-ray single crystal structural analysis showed that a crown-like AuI 6 AgI 6 macrocycle is aligned around two parallelly stacked μ6 -(C3 N6 H3 )3- moieties hold together with π-π interactions. Theoretical calculations revealed that the [μ6 -(C3 N6 H3 )3- ]2 motif dominantly contributes to the near-occupied orbitals in the electronic structure, which is closely related to its luminescence properties. This work demonstrates that the supramolecular templates containing multiple symmetric binding sites may present a facile approach in the construction of functional metal clusters.

Assembly of Luminescent Chiral Gold(I)-Sulfido Clusters via Chiral Self-Sorting

Due to the ubiquity of chirality in nature, chiral self-assembly involving self-sorting behaviors has remained as one of the most important research topics of interests. Herein, starting from a racemic mixture of SEG-based (SEG=SEGPHOS) chlorogold(I) precursors, a unique chiral butterfly-shape hexadecanuclear gold(I) cluster (Au16 ) with different ratios of RSEG and SSEG ligands is obtained via homoleptic and heterochiral self-sorting. More interestingly, by employing different chlorogold(I) precursors of opposite chirality (such as RSEG -Au2 and SBIN -Au2 (BIN=BINAP)), an unprecedented heteroleptic and heterochiral self-sorting strategy has been developed to give a series of heteroleptic chiral decanuclear gold(I) clusters (Au10 ) with propellor-shape structures. Heterochiral and heteroleptic self-sorting have also been observed between enantiomers of homoleptic chiral Au10 clusters to result in the heteroleptic chiral Au10 clusters via cluster-to-cluster transformation. Incorporation of heteroleptic ligands is found to decrease the symmetry from S4 of homoleptic meso Au10 to C2 of heteroleptic chiral Au10 clusters. The chirality has been transferred from the axial chiral ligands and stored in the heteroleptic gold(I) clusters.

E- or Z-Isomers Arising from the Geometries of Ligands in the Mercury Complex of 2-(Anthracen-9-ylmethylene)-N-phenylhydrazine Carbothioamide

An anionic mercury(II) complex of 2-(anthracen-9-ylmethylene)-N-phenylhydrazine carbothioamide (HATU) and two isomers of a neutral mercury(II) complex of the anion of the same ligand (ATU) were reported. The anionic complex [Hg(HATU)2Cl2]·CH2Cl2 had a monodentate HATU ligand (a neutral form of the ligand) and chloride ligands. The two conformational isomers were of the neutral mercury(II) complex Hg(ATU)2·2DMF. The two isomers were from the E or Z geometry of the ligands across the conjugated C=N-N=C-N scaffold of the coordinated ligand. The two isomers of the complex were independently prepared and characterized. The spectroscopic properties of the isomers in solution were studied by 1H NMR as well as fluorescence spectroscopy. Facile conversion of the E-isomer to the Z-isomer in solution was observed. Density functional theory (DFT) calculations revealed that the Z-isomer of the complex was stable compared to the E-isomer by an energy of 14.35 kJ/mol; whereas, E isomer of the ligand was more stable than Z isomer by 8.37 KJ/mol. The activation barrier for the conversion of the E-isomer to the Z-isomer of the ligand was 167.37 kJ/mol. The role of the mercury ion in the conversion of the E-form to the Z-form was discussed. The mercury complex [Hg(HATU)2Cl2]·CH2Cl2 had the E-form of the ligand. Distinct photophysical features of these mercury complexes were presented.

Dicarboxylic Acids Induced Tandem Transformation of Silver Nanocluster

Structural transformation of metal nanoclusters (NCs) is of great ongoing interest regarding their synthesis, stability, and reactivity. Although sporadic examples of cluster transformations have been reported, neither the underlying transformation mechanism nor the intermediates are unambiguous. Herein, we have synthesized a flexible 54-nuclei silver cluster (Ag54) by combining soft (tBuC≡C-) and hard (nPrCOO-) ligands. The existence of weakly coordinated nPrCOO- enhances the reactivity of Ag54, thus facilitating the dicarboxylic acid to induce structural transformation. X-ray structural analyses reveal that Ag54 transforms to Ag28 cluster-based 2D networks (Ag28a and Ag28b) induced by H2suc (succinic acid) and H2glu (glutaric acid), whereas with H2pda (2,2'-(1,2-phenylene)diacetic acid), a discrete Ag28 cluster (Ag28c) is isolated. The key intermediate Ag17 that emerges during the self-dissociation of Ag54 was isolated by using cryogenic recrystallization and characterized by X-ray crystallography. The "tandem transformation" mechanism for the structure evolution from Ag54 to Ag28a is established by time-dependent electrospray ionization mass spectrometry (ESI-MS) and UV-vis spectroscopy. In addition, the catalytic activity in the 4-nitrophenol reduction follows the sequence Ag28c > Ag28b > Ag28a > Ag54 due to more bare silver sites on the surface of the Ag28 cluster unit. Our findings not only open new avenues to the synthesis of silver NCs but also shed light on a better understanding of the structural transformation mechanism from one cluster to another or cluster-based metal-organic networks induced by dicarboxylates.

Construction and Hierarchical Self-Assembly of Multifunctional Coordination Cages with Triangular Metal-Metal-Bonded Units

Herein, a series of face-capped (Tr₂M₃)₄L₄ (Tr = cycloheptatrienyl cationic ring; M = metal; L = organosulfur ligand) tetrahedral cages 1-3 functionalized with 12 appended crown ether moieties were designed and synthesized. The reversible binding of ammonium cations with peripheral crown ether moieties to adjust internal guest-binding was realized. Combination of a bisammonium linker and cage 3 led to the formation of a supramolecular gel SPN1 via host-guest interactions between the crown ether moieties and ammonium salts. The obtained supramolecular gel exhibited multiple-stimuli responsiveness, injectability, and excellent self-healing properties and could be further developed to a SPN1-based drug delivery system. In addition, the storage modulus of SPN1 was 20 times higher than that of the model gel without Pd-Pd bonded blocks, and SPN1 had better self-healing properties compared with the latter, demonstrating the importance of such cages in improving mechanical strength without losing the dynamic properties of the material. The cytotoxicity in vitro of the drug-loaded (doxorubicin or methotrexate) SPN1 was significantly improved compared to that of free drugs.

Photo- and Temperature-Induced Reversible Structural Transformation between Dodecanuclear and Pentadecanuclear Gold(I) Sulfido Complexes

Stimuli-responsive structural transformation has attracted much attention for its potential to mimic the behavior of biological transformations and functions. Here, two unprecedented dodecanuclear and pentadecanuclear gold(I) sulfido clusters (denoted trans-Au₁₂ and trans-Au₁₅, respectively) with impressive stimuli-responsive interconversion have been obtained by taking advantage of the judiciously designed tridentate phosphine ligand L_trans as the building block. Both UV light and temperature can be applied to trigger the structural conversions between trans-Au₁₂ and trans-Au₁₅. In addition, NMR, high-resolution electrospray ionization mass spectrometry, and UV-vis absorption spectroscopy have been employed to monitor the transformation process and decipher the mechanism of structural conversion. This work not only provides a paradigm to investigate photo-induced cluster-to-cluster transformation based on polydentate phosphine ligands but also offers a new direction for the construction of the stimuli-responsive materials.

Solvato-Controlled Assembly and Structural Transformation of Emissive Poly-NHC-Based Organometallic Cages and Their Applications in Amino Acid Sensing and Fluorescence Imaging

Stimuli-induced structural transformation of supramolecular cages has drawn increasing attention because of their sensitive feature to external variations as model systems to simulate biological processes. However, combining structural transformation and useful functions has remained a difficult task. This study reports the solvato-controlled self-assembly of two unique topologies with different emission characteristics, a water-soluble Ag₈ L₄ cage (A) and an Ag₄ L₂ cage (B), produced from the same sulfonate-pendant tetraphenylethene (TPE) bridged tetrakis-(1,2,4-triazolium) ligand. Both cages show interesting solvent-responsive reversible structural transformation, and the change of fluorescence signals can efficiently track the process. Additionally, water-soluble cage A exhibits unique properties in thermochromism, thiol amino acid sensing, and subcellular imaging in aqueous media.

Synthesis, Electrochemistry, Photophysics, and Photochemistry of a Discrete Tetranuclear Copper(I) Sulfido Cluster

A tetranuclear copper(I) complex, [Cu₄{μ-(Ph₂P)₂NH}₄(μ₄-S)](PF₆)₂ (1), was synthesized. It was found to display intense and long-lived phosphorescence in the solid and solution states. The lowest-energy excited state was assigned as ligand-to-metal charge transfer (LMCT) [S^2- → Cu₄] mixed with some metal-centered (ds/dp) character. In addition, the phosphorescent state of this complex was found to be quenched by pyridinium acceptors via an oxidative electron-transfer quenching process. An excited-state reduction potential of -1.74 V versus saturated salt calomel electrode was estimated through oxidative quenching studies with a series of structurally related pyridinium acceptors, indicative of its strong reducing power in the excited state. From the transient absorption difference spectrum of the tetranuclear copper(I) sulfido complex and 4-(methoxycarbonyl)-N-methylpyridinium hexafluorophosphate, in addition to the characteristic absorption of the pyridinyl radical at ca. 395 nm, two absorption bands at ca. 500 and 660 nm were also observed. The former was assigned as an LMCT absorption [S^2- → Cu₄] and the latter as an intervalence charge-transfer transition, associated with the mixed-valence species Cu^I/Cu^I/Cu^I/Cu^II.

Insights into mechanisms of diphosphine-mediated controlled surface construction on Au nanoclusters

Unraveling the rules governing the size regulation of nanoclusters is of great importance not only in fundamental research, but also in practical applications because of the high structure-property correlation in nanoclusters. Diphosphine-mediated size tailoring is recognized as a powerful method for modulating the size, configuration, and properties of nanoclusters, but the role of diphosphines in these size-controlled processes is still poorly understood due to a lack of systematic studies. Herein, using Au₂₃(SR)₁₆^- as the template for modification, the factors influencing the size-modulation of nanoclusters by diphosphines were systematically investigated. It is revealed that by controlling the length of the diphosphines (from shorter to longer), Au₂₁(SR)₁₂L₂⁺ (L = diphosphine) and Au₂₂(SR)₁₄L can be produced. Moreover, introducing a rigid group into the diphosphines can twist the structural framework or lead to the formation of a new surface motif configuration in the nanoclusters, forming twisted Au₂₂(SR)₁₄L and Au₂₅(SR)₁₆L₂⁺. The size regulation of these nanoclusters enables fine-tuning of the optical properties, including the absorption wavelengths and photoluminescence emission intensity, affording an avenue for precise control of the physicochemical properties of nanoclusters for practical applications.

Stimuli-Induced Reversible Transformation between Decanuclear and Pentanuclear Gold(I) Sulfido Complexes

Decanuclear and pentanuclear gold(I) sulfido complexes of phenanthrene- and dibenzothiophene-based diphosphine ligands were synthesized and characterized. Unprecedented stimuli-induced reversible transformation between decanuclear and pentanuclear gold(I) sulfido complexes was observed, which could be readily monitored by NMR and UV-vis absorption spectroscopy in solution. Remarkably, the decanuclear gold(I) sulfido complex (Au₁₀-L^Ph) was found to show a highly reversible transformation process, which is stable for over 10 successive cycles in solution. The stimuli-induced reversible transformation behavior of the gold(I) sulfido complexes was found to depend on the P-P bite distance of the bidentate phosphine ligands.

The Backbone of Success of P,N-Hybrid Ligands: Some Recent Developments

Organophosphorus ligands are an invaluable family of compounds that continue to underpin important roles in disciplines such as coordination chemistry and catalysis. Their success can routinely be traced back to facile tuneability thus enabling a high degree of control over, for example, electronic and steric properties. Diphosphines, phosphorus compounds bearing two separated PIII donor atoms, are also highly valued and impart their own unique features, for example excellent chelating properties upon metal complexation. In many classical ligands of this type, the backbone connectivity has been based on all carbon spacers only but there is growing interest in embedding other donor atoms such as additional nitrogen (-NH-, -NR-) sites. This review will collate some important examples of ligands in this field, illustrate their role as ligands in coordination chemistry and highlight some of their reactivities and applications. It will be shown that incorporation of a nitrogen-based group can impart unusual reactivities and important catalytic applications.

Design of a gold clustering site in an engineered apo-ferritin cage

Water-soluble and biocompatible protein-protected gold nanoclusters (Au NCs) hold great promise for numerous applications. However, design and precise regulation of their structure at an atomic level remain challenging. Herein, we have engineered and constructed a gold clustering site at the 4-fold symmetric axis channel of the apo-ferritin cage. Using a series of X-ray crystal structures, we evaluated the stepwise accumulation process of Au ions into the cage and the formation of a multinuclear Au cluster in our designed cavity. We also disclosed the role of key residues in the metal accumulation process. X-ray crystal structures in combination with quantum chemical (QC) calculation revealed a unique Au clustering site with up to 12 Au atoms positions in the cavity. Moreover, the structure of the gold nanocluster was precisely tuned by the dosage of the Au precursor. As the gold concentration increases, the number of Au atoms position at the clustering site increases from 8 to 12, and a structural rearrangement was observed at a higher Au concentration. Furthermore, the binding affinity order of the four Au binding sites on apo-ferritin was unveiled with a stepwise increase of Au precursor concentration.

Photocontrolled multiple-state photochromic benzo[b]phosphole thieno[3,2-b]phosphole-containing alkynylgold(I) complex via selective light irradiation

Photochromic materials have drawn growing attention because using light as a stimulus has been regarded as a convenient and environmental-friendly way to control properties of smart materials. While photoresponsive systems that are capable of showing multiple-state photochromism are attractive, the development of materials with such capabilities has remained a challenging task. Here we show that a benzo[b]phosphole thieno[3,2‑b]phosphole-containing alkynylgold(I) complex features multiple photoinduced color changes, in which the gold(I) metal center plays an important role in separating two photoactive units that leads to the suppression of intramolecular quenching processes of the excited states. More importantly, the exclusive photochemical reactivity of the thieno[3,2‑b]phosphole moiety of the gold(I) complex can be initiated upon photoirradiation of visible light. Stepwise photochromism of the gold(I) complex has been made possible, offering an effective strategy for the construction of multiple-state photochromic materials with multiple photocontrolled states to enhance the storage capacity of potential optical memory devices.

Site-specific sulfur-for-metal replacement in silver nanocluster

A new Ag36 nanocluster with a closed electronic structure and eight valence electrons is reported, which has a similar structure to an open-shell Ag34 nanocluster with three valence electrons, except...

Switching the Local Symmetry from D5h to D4h for Single-Molecule Magnets by Non-Coordinating Solvents

A solvent effect towards the performance of two single-molecule magnets (SMMs) was observed. The tetrahydrofuran and toluene solvents can switch the equatorial coordinated 4-Phenylpyridine (4-PhPy) molecules from five to four, respectively, in [Dy(OtBu)2(4-PhPy)5]BPh41 and Na{[Dy(OtBu)2(4-PhPy)4][BPh4]2}∙2thf∙hex 2. This alternation significantly changes the local coordination symmetry of the Dy(III) center from D5h to D4h for 1 and 2, seperately. Magnetic studies show that the magnetic anisotropy energy barrier of 2 is higher than that of 1, while the relation of blocking temperature is just on the contrary due to the symmetry effect. The calculations of the electrostatic potential successfully explained the driving force of solvents for the molecular structure change, confirming the feasibility of adjusting the performance of SMMs via diverse solvents.

Redox-Induced Interconversion of Two Au8 Nanoclusters: the Mechanism and the Structure-Bond Dissociation Activity Correlations

The interconversion of atomically precise nanoclusters represents an excellent platform to understand the structural correlations of nanomaterials at the atomic level. Herein, density functional theory calculations were performed to elucidate the mechanism of the redox-induced interconversion of [Au₈(dppp)₄]²⁺ and [Au₈(dppp)₄Cl₂]²⁺ (dppp is short for 1,3-bis(diphenylphosphino)propane) nanoclusters. Reduction is the driving force for the conversion of [Au₈(dppp)₄Cl₂]²⁺ to [Au₈(dppp)₄]²⁺, while the Au-Au and first Au-Cl bond dissociations occur asynchronously on the two different corner Au atoms to avoid the formation of an electron-deficient Au atom. By contrast, the reduced electron density of [Au₈(dppp)₄]²⁺ by oxidation with O₂ weakens the outmost Au-Au bond therein and facilitates the coordination of the electron-rich chloride(s). The reduction- and oxidation-induced activations, respectively, of Au-Cl and Au-Au bonds and the elucidated principles on the structure-activity correlations might also be generalized to other size conversions upon redox treatment.

Dual Emissive Gold(I)-Sulfido Cluster Framework Capable of Benzene-Cyclohexane Separation in the Solid State Accompanied by Luminescence Color Changes

A decanuclear gold(I)-sulfido complex, [(L^H)₄Au₁₀S₄]Cl₂ (L^H-Au₁₀S₄-Cl, where L^H = 4,5-bis(diphenylphosphanyl)-2H-1,2,3-triazole), assembled from the reaction of H₂S with the chlorogold(I) precursor obtained from the click reaction of [dppa(AuCl)₂] (where dppa = 1,2-bis(diphenylphosphino)acetylene) with NaN₃, is shown to display a bright dual green and red emission in the solid state. Single crystal X-ray diffraction (SCXRD) studies indicate a gold(I) cluster-based framework assembled through intermolecular halogen···hydrogen bonds as well as other weak interactions. The framework of L^H-Au₁₀S₄-Cl is found to display high stability toward solvent molecules, with capability to encapsulate solvent molecules, such as benzene and cyclohexane, inside the crystal lattice voids via a single-crystal-to-single-crystal (SCSC) transformation. With different degrees of influence on the dual green and red emission, crystalline solids of L^H-Au₁₀S₄-Cl exhibit remarkable solvatochromic luminescence in the presence of benzene and cyclohexane. Notably, due to the size confinement of the lattice cavities, the L^H-Au₁₀S₄-Cl solids exhibit a high selectivity (>95%) toward benzene in a mixture of equimolar concentration of benzene and cyclohexane. This work has demonstrated the promising capability of gold(I)-sulfido cluster frameworks to serve as luminescent functional materials for the separation of benzene and cyclohexane.

The pivotal alkyne group in the mutual size-conversion of Au9 with Au10 nanoclusters

Herein, density functional theory (DFT) calculations were performed to elucidate the mechanism of the reversible single atom size conversion between [Au10(DMPP)4(C6H11C[triple bond, length as m-dash]C)]3+ and [Au9(DMPP)4]3+ (DMPP is 2,2'-bis-(dimethylphosphino)-1,1'-biphenyl, the simplified, theoretical model of the experimentally used 2,2'-bis-(diphenylphosphino)-1,1'-binaphthyl). The presence of a unique alkyne group is pivotal to the nucleophilic attack of the phosphine ligand on the electron-deficient Au10 core. After that, a formal ligand exchange and facile 1,2-P (of the diphosphine ligand) transfer occur to generate the Au9 cluster product. By contrast, the absence of the alkyne group results in a relatively electron-rich Au9 core, and thus an electrophilic attack of the Au(alkyne) complex on the most electron-rich metal sites occurs first. After that, the Au(alkyne) migration on the cluster surface, 1,2-P transfer and core-reconstruction occur successively to generate the thermodynamically highly stable Au10 cluster product.

Keep it tight: a crucial role of bridging phosphine ligands in the design and optical properties of multinuclear coinage metal complexes

Copper subgroup metal ions in the +1 oxidation state are classical candidates for aggregation via non-covalent metal-metal interactions, which are supported by a number of bridging ligands. The bridging phosphines, soft donors with a relatively labile coordination to coinage metals, serve as convenient and essential components of the ligand environment that allow for efficient self-assembly of discrete polynuclear aggregates. Simultaneously, accessible and rich modification of the organic spacer of such P-donors has been used to generate many fascinating structures with attractive photoluminescent behavior. In this work we consider the development of di- and polynuclear complexes of M(i) (M = Cu, Ag, Au) and their photophysical properties, focusing on the effect of phosphine bridging ligands, their flexibility and denticity.

Elaborate Design of Ag8Au10 Cluster [2]Catenane Phosphors for High-Efficiency Light-Emitting Devices

In this work, rational design of highly soluble and phosphorescent Ag-Au cluster complexes with exceptional [2]catenane structures is conducted using 1,8-diethynyl-9H-carbazole (H₃decz) as a rigid U-shaped ligand with a distinguished hole-transport character. The self-assembly reaction of H₃decz, Au⁺, and Ag⁺ generated phosphorescent Ag₄Au₆ cluster 1 (Φ_em = 0.22 in CH₂Cl₂) with H₂decz^- having a free ethynyl (-C≡CH) group. When the four free C≡CH groups in the Ag₄Au₆ complex 1 are further bound to four (PPh₃)Au⁺ and four (PPh₃)Ag⁺ moieties through M-acetylide linkages, the formation of Ag₈Au₁₀ cluster 2 not only eliminates nonradiative ethynyl C-H vibrational deactivation process but also improves dramatically the molecular rigidity so that the phosphorescent efficiency of the Ag₈Au₁₀ cluster 2 (Φ_em = 0.63) is nearly 3 times that of the Ag₄Au₆ cluster 1. The Ag₈Au₁₀ cluster structure is further rigidified using diphsophine Ph₂P(CH₂)₄PPh₂ (dppb) in place of PPh₃ so that the phosphorescence of the Ag₈Au₁₀ cluster 3 (Φ_em = 0.77) is more efficient than that of 2. Making use of the Ag₈Au₁₀ clusters as phosphorescent dopants, high-efficiency solution-processed organic light-emitting diodes (OLEDs) were achieved with current efficiency (CE) and external quantum efficiency (EQE) of 47.2 cd A^-1 and 15.7% for complex 2 and 50.5 cd A^-1 and 14.9% for complex 3.

Spontaneous Resolution of Chiral Multi-Thiolate-Protected Ag30 Nanoclusters

Despite significant progress achieved in the preparation of chiral nanoparticles, the enantioseparation of racemates still presents a big challenge in nanomaterial research. Herein, we report the synthesis and structural characterization of racemic anisotropic nanocluster Ag₃₀(C₂B₁₀H₉S₃)₈Dppm₆ (Ag ₃₀ -rac), which is protected by mixed carboranetrithiolate and phosphine ligands. Spontaneous self-resolution of the racemates was realized through conglomerate crystallization in dimethylacetamide (DMAc). The homochiral nanoclusters in the racemic conglomerates adopt enantiomeric helical self-assemblies (R/L-Ag ₃₀ ). Diverse noncovalent interactions as the driving force in directing superstructure packing were elucidated in detail. Furthermore, the nanoclusters show red luminescence in both solid and solution states, and the racemic conglomerates display a mirror-image CPL response. This work provides atom-precise helical nanoparticle superstructures that facilitate an in-depth understanding of the helical-assembly mechanism.