Two ligand‐protected nanoscale silver moieties, [Ag46(SPhMe2)24(PPh3)8](NO3)2 and [Ag40(SPhMe2)24(PPh3)8](NO3)2 (abbreviated as Ag46 and Ag40, respectively) with almost the same shell but different cores were synthesized simultaneously. As their external structures are identical, the clusters were not distinguishable and become co‐crystallized. The occupancy of each cluster was 50 %. The outer shell of both is composed of Ag32S24P8, which is reminiscent of fullerenes, and it encapsulates a well‐studied core, Ag14 and a completely new core, Ag8, which correspond to a face‐centered cube and a simple cube, respectively, resulting in the Ag46 and Ag40 clusters. The presence of two entities (Ag40 and Ag46 clusters) in a single crystal and their molecular formulae were confirmed by detailed electrospray ionization mass spectrometry. The optical spectrum of the mixture showed unique features which were in good agreement with the results from time‐dependent density functional theory (TD‐DFT).

We introduce a cluster coprotected by thiol and diphosphine ligands, [Ag22(dppe)4(2,5-DMBT)12Cl4]2+ (dppe = 1,2-bis­(diphenylphosphino)­ethane; 2,5-DMBT= 2,5-dimethylbenzenethiol), which has an Ag10 core encapsulated by an Ag12(dppe)4(2,5-DMBT)12Cl4 shell. The Ag10 core comprises two Ag5 distorted trigonal bipyramidal units and is uncommon in Au and Ag nanoclusters. The electrospray ionization mass spectrum reveals that the cluster is divalent and contains four free electrons. An uncommon crystallization-induced enhancement of emission is observed in the cluster. The emission is weak in the solution and amorphous states. However, it is enhanced 12 times in the crystalline state compared to the amorphous state. A detailed investigation of the crystal structure suggests that well-arranged C–H···π and π···π interactions between the ligands are the major factors for this enhanced emission. Further, in-depth structural elucidation and density functional theory calculations suggest that the cluster is a superatom with four magic electrons.

We report the systematic appearance of a plasmon-like optical absorption feature in silver clusters protected with 2-phenylethanethiol (PET), 4-flurothiophenol (4-FTP) and (4-(t-butyl)benzenethiol (BBS) as a function of cluster size. A wide range of clusters, namely, Ag₄₄(4-FTP)₃₀, Ag₅₅(PET)₃₁, ∼Ag₇₅(PET)₄₀, ∼Ag₁₁₄(PET)₄₆, Ag₁₅₂(PET)₆₀, ∼Ag₂₀₂(BBS)₇₀, ∼Ag₄₂₃(PET)₁₀₅, and ∼Ag₅₃₀(PET)₁₀₀ were prepared. The UV/Vis spectra show multiple features up to ∼Ag₁₁₄; and thereafter, from Ag₁₅₂ onwards, the plasmonic feature corresponding to a single peak at ∼460 nm evolves, which points to the emergence of metallicity in clusters composed of ∼150 metal atoms. A minor blue shift in the plasmonic peak was observed as cluster sizes increased and merged with the spectrum of plasmonic nanoparticles of 4.8 nm diameter protected with PET. Clusters with different ligands, such as 4-FTP and BBS, also show this behavior, which suggests that the 'emergence of metallicity' is independent of the functionality of the thiol ligand.

We present an example of an interparticle reaction between atomically precise nanoclusters (NCs) of the same metal, resulting in entirely different clusters. In detail, the clusters [Ag 12 (TBT) 8 (TFA) 5 (CH 3 CN)] + (TBT = tert-butylthiolate, TFA = trifluoroacetate, CH 3 CN = acetonitrile) and [Ag 18 (TPP) 10 H 16 ] 2+ (TPP = triphenylphosphine) abbreviated as Ag 12 and Ag 18 , respectively, react leading to [Ag 16 (TBT) 8 (TFA) 7 (CH 3 CN) 3 Cl] + and [Ag 17 (TBT) 8 (TFA) 7 (CH 3 CN) 3 Cl] + , abbreviated as Ag 16 and Ag 17 , respectively. The two product NCs crystallize together as both possess the same metal chalcogenolate shell, composed of Ag 16 S 8 , making them indistinguishable. The occupancies of Ag 16 and Ag 17 are 66.66 and 33.33%, respectively, in a single crystal. Electrospray ionization mass spectrometry (ESI MS) of the reaction product and a dissolved crystal show the population of Ag 16 and Ag 17 NCs to be in a 1:1 and 2:1 ratio, respectively. This suggests selective crystallization in the cocrystal. Time-dependent ESI MS was employed to understand the formation of product clusters by monitoring the reaction intermediates formed in the course of the reaction. We present an unprecedented growth mechanism for the formation of silver NCs mediated by silver thiolate intermediates. KEYWORDS: nanoclusters, intercluster reactions, homometallic clusters, cocrystals, Ag 16 and Ag 17 A tomically precise noble metal nanoclusters (NCs) are an emerging class of materials. Studies on them are motivated by their unusual structures and associated properties. 1−6 NCs possess exceptional geometric and electronic structures, having a core size below 3 nm, exhibiting intriguing properties due to molecule-like energy levels, strong photoluminescence, color tunability, high catalytic activity, facile surface tailorability, and good photostability, which are different from bulk nanoparticles, with diameters >3 nm. 3−7 Scalable fabrication of the NCs results in new materials with distinctly different applications. 8,9 Attempts to design novel NCs have been there using diverse methodologies. Clusters with varying cores can be obtained by different synthetic procedures such as size focusing methodology, 10,11 interparticle reactions, 12 and many others. 2−6 To understand the distinct properties of NCs, detailed knowledge of their structures is important. In the recent past, atomically precise silver (Ag) nanoclusters with a wide range of nuclearity have been characterized, including

We report the crystal structure of a supramolecular coassembly of a red luminescent silver cluster, [Ag29(BDT)12(TPP)4]3– (referred to as Ag29) (BDT, 1,3-benzene dithiol; TPP, triphenyl phosphine), with dibenzo-18-crown-6 (DB18C6). The structure may be viewed as crystallization-induced self-organization of DB18C6 molecules into cage-like hexamers in the interstitial spaces of the lattice of trigonal Ag29 (Ag29T) clusters, which resulted in an anisotropic expansion of the Ag29T lattice along its z-axis. This structure corresponds to a new family of “lattice inclusion” compounds in nanoclusters. Supramolecular forces guide the assembly of the clusters and the crown ethers, which pack into complex hierarchical patterns in their crystal lattice. We identified the effect of such a coassembly on the solid-state luminescence of the cluster. The crystals containing the coassembly were ∼3.5-fold more luminescent than the parent Ag29T crystals. We also used high-resolution electrospray ionization mass spectrometry to get further insights into the nature of the complexation between Ag29 cluster and DB18C6. This study provides a new strategy for designing cluster-assembled functional materials with enhanced properties.

atomically precise nanocluster (NC)-based metal−organic frameworks (MOFs) with properties richer than those of NCs themselves are emerging materials. However, fabricating such materials with good stability has not been easy. In this work, a facile synthetic strategy was employed for t h e c r e a t i o n o f s i l v e r N C − M O F s s t a r t i n g f r o m [Ag 12 (TBT) 7 (TFA) 4 (CH 3 CN) 6 ] + , facilitated by heterocyclic amines, 4,4′-bipyridine (bpy) and pyrazine (pyz), via metal−metal and metalsulfide rearrangement reactions, where TBT and TFA are tertiarybutylthiolate and trifluoroacetate, respectively. In one of the reactions, the pyz ligand facilitates the formation of a 2D framework with a trigonal crystal system, which exhibits high stability and emits bright green luminescence at low temperatures. Owing to its facile synthesis, good stability, efficient luminescence, uniform porosity, and layered structure, the resultant hexagonal 2D nanosheets can be efficiently exfoliated from parent crystals. The 2D nanosheets are structurally similar to graphene. A top-down approach was employed for the exfoliation of stable 2D nanosheets with lateral dimensions in the range of 0.156 μm. In another case, the bpy ligand induces the construction of a 3D framework with an orthorhombic crystal system. Owing to its interpenetrated AB•••AB structure, robustness, and efficient green luminescence at room temperature, the resultant 3D MOF is capable of functioning as a high-performance luminescent sensor for selective detection of explosive analogues, 2-nitrotoluene and 2,4-dinitrotoluene, with excellent recyclability. However, in the absence of the heterocyclic amines, a pristine AgNC was formed. Time-dependent density functional theory calculations were employed to understand the mechanism of energy transfer in AgNC-MOFs. Our strategy offers an unprecedented approach in which heterocyclic amines facilitate intramolecular rearrangement reactions, resulting in 2D and 3D atomically precise NC framework materials. This work not only demonstrates the creation of 2D and 3D materials but also provides new insights into the critical surface coordination chemistry controlled by heterocyclic amines for defining the morphology and properties of cluster frameworks.

Two ligand‐protected nanoscale silver moieties, [Ag46(SPhMe2)24(PPh3)8](NO3)2 and [Ag40(SPhMe2)24(PPh3)8](NO3)2 (abbreviated as Ag46 and Ag40, respectively) with almost the same shell but different cores were synthesized simultaneously. As their external structures are identical, the clusters were not distinguishable and become co‐crystallized. The occupancy of each cluster was 50 %. The outer shell of both is composed of Ag32S24P8, which is reminiscent of fullerenes, and it encapsulates a well‐studied core, Ag14 and a completely new core, Ag8, which correspond to a face‐centered cube and a simple cube, respectively, resulting in the Ag46 and Ag40 clusters. The presence of two entities (Ag40 and Ag46 clusters) in a single crystal and their molecular formulae were confirmed by detailed electrospray ionization mass spectrometry. The optical spectrum of the mixture showed unique features which were in good agreement with the results from time‐dependent density functional theory (TD‐DFT).

The systematic size evolution of organic‐soluble, atomically precise silver clusters (product 1) to superlattices (SLs) is reported. Creation of nanoparticle crystals starting from atomically precise clusters points to the synthesis of materials with tunable propertiesOk.