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Quantum-tunneling-based nanoelectronics has the potential for the miniaturization of electronics toward the sub-5 nm scale. However, the nature of phase-coherent quantum tunneling leads to the rapid decays of the electrical conductance with tunneling transport distance, especially in organic molecule-based nanodevices. In this work, we investigated the conductance of the single-cluster junctions of a series of atomically well-defined silver nanoclusters, with varying sizes from 0.9 to 3.0 nm, using the mechanically controllable break junction (MCBJ) technique combined with quantum transport theory. Our charge transport investigations of these single-cluster junctions revealed that the conductance grows with increasing cluster size. The conductance decay constant was determined to be ∼-0.4 nm

We demonstrate in this work that N-methyl-2-pyrrolidone (NMP) is a superior alternative to dimethyl sulfoxide (DMSO) as an additive in a precursor solution for the fabrication of high-quality perovskite films for solar cells. While the DMSO-assisted method always requires the films to be prepared with a low and restricted PdI2 : DMSO ratio, NMP provides a much wider window of the PbI2/NMP ratio for the preparation of high-quality perovskite films. The systematic studies on the structures of intermediates obtained with different PbI2/NMP ratios reveal that only one kind of intermediate forms regardless of the Pb2+/NMP ratio between 1 and 4, which is totally different from the situation of a PbI2/DMSO system. But all the perovskite solar cell devices fabricated with different Pb2+/NMP ratios show similar performances to their counterpart fabricated with 1 : 1 Pb2+/DMSO. Besides the MAPbI3 (MA = CH3NH3+) system, NMP is shown to be an excellent coordinative additive for the fabrication of high-quality triple-cation (Cs+/formamidinium/MA) perovskite films.

Bone tissues are the main metastatic sites of many cancers, and bone metastasis is an important cause of death. When bone metastasis occurs, dynamic interactions between tumor cells and bone tissues promote changes in the tumor-bone microenvironments that are conducive to tumor growth and progression, which also promote several related diseases, including pathological fracture, bone pain, and hypercalcemia. Accordingly, it has obvious clinical benefits for improving the cure rate and reducing the occurrence of related diseases through targeting bone microenvironments for the treatment and early detection of cancer bone metastasis niches. In this review, we briefly analyzed the relationship between bone microstructures and tumor metastasis, as well as microenvironmental changes in osteoblasts, osteoclasts, immune cells, and extracellular and bone matrixes caused when metastatic tumor cells colonize bones. We also discuss novel designs in nanodrugs for inhibiting tumor proliferation and migration through targeting to tumor bone metastases and abnormal bone-microenvironment components. In addition, related researches on the early detection of bone and multi-organ metastases by nanoprobes are also introduced. And we look forward to providing some useful proposals and enlightenments on nanotechnology-based drug delivery and probes for the treatment and early detection of bone metastasis.

Background: Clinical progress of α4-1BB has been impeded by hepatotoxicity. Current research is focused on improving targeted delivery of α4-1BB to the tumor using tumor-specific markers. However, targeted delivery of 4-1BB agonists to tumors faces challenges due to a lack of tumor biomarkers and effector T cells within tumors. To overcome these challenges, we developed antigen-independent targeting approach based on unnatural sugar-mediated metabolic glycoengineering and bio-orthogonal click chemistry to deliver α4-1BB to tumors. We utilized nanoparticles that can deliver a sugar analogue containing click-chemistry moiety to the tumor microenvironment. Method: The Ac4ManNAz was loaded in mPEG-PLGA nanoparticles (MazNP), and the loading efficiency was determined by HPLC. DBCO-functionalized α4-1BB (DBCO-α4-1BB) was synthesized via amine-NHS coupling reaction. The tumor inhibition efficiency was assessed on mice bearing different tumor models. Mice were either inoculated subcutaneously on the left flank (75,000 B16F10 cells) or injected on the left fourth mammary fat pad (100,000 4T1 cells). Mice were given MazNPs (IV) on day 5, 6, 10, and 11, and DBCO-α4-1BB (IV) and αPD-1 (IP) on day 8 and 13. T lymphocytes were analyzed by fluorescent IF staining. Serum liver enzyme was examined to evaluate hepatotoxicity of treatments. Liver pathology was assessed by H&E and CD8+ IHC staining. Results: The αPD1 plus DBCO-α4-1BB with MazNPs showed a 36.4% cure rate, compared to 0% of αPD1 plus DBCO-α4-1BB or αPD1 plus DBCO-α4-1BB with free Ac4ManNAz in B16F10 melanoma model. We then re-challenged the cured mice with 200,000 B16F10 cells and 50% of cured mice survived without any further treatment. In 4T1 breast cancer model, the survival data analyzed using the log-rank test showed that the median survival of αPD1 plus DBCO-α4-1BB with MazNP was increased by 71%, compared to the PBS, and 26% αPD1 plus α4-1BB or αPD1 plus DBCO-α4-1BB with free Ac4ManNAz. We showed that the involvement of NK and CD8+ T cells in the antitumor efficacy of αPD1 plus DBCO-α4-1BB with MazNP. Notably, a massive CD8+ T cell infiltration in the liver was observed in both αPD1 plus α4-1BB (29.8 ± 18.2%) and αPD1 plus DBCO-α4-1BB with Ac4ManNAz (22.1 ± 10.9), significantly higher than PBS control (0.9 ± 0.6%), while the percentage of CD8+ T cells in the MazNP treatment (5.4 ± 5.8%) was five times lower. Hepatotoxicity was further confirmed by serum liver enzyme analysis that ALT and AST levels were substantially elevated by αPD1 plus α4-1BB or αPD1 plus DBCO-α4-1BB with free Ac4ManNAz, as compared to PBS control group, while the MazNP-treated mice had normal serum ALT and AST levels except for one. Conclusion: Our findings demonstrated that antigen-independent targeted delivery of α4-1BB can improve anti-tumor immune responses while reducing hepatotoxicity. Citation Format: Hyesun Hyun, Bo Sun, Stephanie A. Montgomery, Teresa Griffin, Juanzhu Yan, Albert Wielgus, Yue Wang, Tian Zhang, Jianjun Cheng, Andrew Z. Wang. Antigen-independent delivery of 4-1BB agonist to the tumor microenvironment improves immune response while reducing hepatotoxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 296.

A comprehensive understanding of chemical bonding and reactions at the surface of nanomaterials is of great importance in the rational design of their functional properties and applications. With the rapid development in cluster science, it has become clear that atomically precise metal clusters represent ideal models for resolving various important and/or unsolved issues related to surface science. This Account highlights our recent efforts on the fabrication of ligand-stabilized coinage nanoclusters with atomic precision from the viewpoint of surface coordination chemistry in particular. The successful synthesis of a large variety of metal clusters in our group has greatly benefitted from the development of an effective amine-assisted NaBH

A general method, using mixed ligands (here diphosphines and thiolates) is devised to turn an achiral metal cluster, Au13 Cu2 , into an enantiomeric pair by breaking (lowering) the overall molecular symmetry with the ligands. Using an achiral diphosphine, a racemic [Au13 Cu2 (DPPP)3 (SPy)6 ]+ was prepared which crystallizes in centrosymmetric space groups. Using chiral diphosphines, enantioselective synthesis of an optically pure, enantiomeric pair of [Au13 Cu2 ((2r,4r)/(2s,4s)-BDPP)3 (SPy)6 ]+ was achieved in one pot. Their circular dichroism (CD) spectra give perfect mirror images in the range of 250-500 nm with maximum anisotropy factors of 1.2×10-3 . DFT calculations provided good correlations with the observed CD spectra of the enantiomers and, more importantly, revealed the origin of the chirality. Racemization studies show high stability (no racemization at 70 °C) of these chiral nanoclusters, which hold great promise in applications such as asymmetry catalysis.

Both the electronic and surface structures of metal nanomaterials play critical roles in determining their chemical properties. However, the non-molecular nature of conventional nanoparticles makes it extremely challenging to understand the molecular mechanism behind many of their unique electronic and surface properties. In this work, we report the synthesis, molecular and electronic structures of an atomically precise nanoparticle, [Ag206L72]q (L = thiolate, halide; q = charge). With a four-shell Ag7@Ag32@Ag77@Ag90 Ino-decahedral structure having a nearly perfect D5h symmetry, the metal core of the nanoparticle is co-stabilized by 68 thiolate and 4 halide ligands. Both electrochemistry and plasmonic absorption reveal the metallic nature of the nanoparticles, which is explained by density functional theory calculations. Electronically, the nanoparticle can be considered as a superatom, just short of a major electron shell closing of 138 electrons (q = –4). More importantly, many of ligands capping on the nanoparticle are labile due to their low-coordination modes, leading to high surface reactivity for catalysing the synthesis of indoles from 2-ethynylaniline derivatives. The results exemplify the power of the atomic-precision nanocluster approach to catalysis in probing reaction mechanisms and in revealing the interplay of heterogeneous reactivities, electronic and surface structural dynamics, thereby providing ways for optimization.

Understanding the nucleation and growth pathways of nanocrystallites allows precise control of the size and shape of functional crystalline nanomaterials of importance in nanoscience and nanotechnology. This paper provides a detailed analysis of the stereochemical and electronic requirements of three series of nanoclusters based on face-centered cubes (fcc) as the basic building blocks, namely, 1-, 2-, and 3-D assemblages of fcc to form superrods (n), supersquares (n2), and supercubes (n3). The generating functions for calculating the numbers (and arrangements) of surface and interior metal atoms, as well as the number and dispositions of the ligands, for these particular sequences of fcc metal clusters of the general formula [Mm(SR)l(PR′3)8]q (where M = coinage metals; SR = thiolates (or group XI ligands), and PR′3 = phosphines) are presented. An electron-counting scheme based on the jelliumatic shell nodel, a variant of the jellium model, predicts the electron requirements and hence the chemical composi...

An efficient yttrium-catalyzed intramolecular hydroalkoxylation/Claisen rearrangement sequence has been achieved, thus enabling facile access to a diverse array of valuable medium-sized lactams. Furthermore, a mechanistic rationale for this novel cascade reaction is well supported by a variety of control experiments.

We report herein the synthesis and structure of a 45-atom trigonal-prismatic Au–Ag bimetallic nanocluster, formulated as Au9Ag36(SPhCl2)27(PPh3)6, based on single-crystal X-ray crystallographic determination. The structure can be described as a core–shell structure with a tricapped trigonal prismatic (ttp1) Au9 core encaged in a larger (frequency-two) tricapped trigonal prismatic (ttp2) Ag30 shell. The cluster is terminated by six Ag(PPh3) moieties which, along with ttp2 and 27 thiolates, constitute the outer trigonal-prismatic (TP) shell. Each of the three nearly coplanar yet severely distorted “square” faces of TP contains 13 Ag atoms which are arranged in a way reminiscent of the (100) face of a face-centered cubic (fcc) structure. Of the 30 edges formed by these quasi-(100) faces of the TP, only 27 are bridged by the thiolate ligands; three are vacant, one on each “square” face. It is believed that these peculiar vacant ligand sites are caused by steric hindrance of the thiolate ligands in combination with the superatomic electronic shell closing of 1S21P61D10 rendering 9(ttp1) + 30(ttp2) + 6(TP) − 27(SR) = 18 jellium electrons.

Copper-hydrides are known catalysts for several technologically important reactions such as hydrogenation of CO, hydroamination of alkenes and alkynes, and chemoselective hydrogenation of unsaturated ketones to unsaturated alcohols. Stabilizing copper-based particles by ligand chemistry to nanometer scale is an appealing route to make active catalysts with optimized material economy; however, it has been long believed that the ligand-metal interface, particularly if sulfur-containing thiols are used as stabilizing agent, may poison the catalyst. We report here a discovery of an ambient-stable thiolate-protected copper-hydride nanocluster [Cu25H10(SPhCl2)18]3- that readily catalyzes hydrogenation of ketones to alcohols in mild conditions. A full experimental and theoretical characterization of its atomic and electronic structure shows that the 10 hydrides are instrumental for the stability of the nanocluster and are in an active role being continuously consumed and replenished in the hydrogenation reaction. Density functional theory computations suggest, backed up by the experimental evidence, that the hydrogenation takes place only around a single site of the 10 hydride locations, rendering the [Cu25H10(SPhCl2)18]3- one of the first nanocatalysts whose structure and catalytic functions are characterized fully to atomic precision. Understanding of a working catalyst at the atomistic level helps to optimize its properties and provides fundamental insights into the controversial issue of how a stable, ligand-passivated, metal-containing nanocluster can be at the same time an active catalyst. peerReviewed

Platinum-catalyzed formal [5+2] and [4+2] annulations of isoxazoles with heterosubstituted alkynes enabled the atom-economical synthesis of valuable 1,3-oxazepines and 2,5-dihydropyridines, respectively. Importantly, this Pt catalysis not only led to unique reactivity dramatically divergent from that observed under Au catalysis, but also proceeded via unprecedented α-imino platinum carbene intermediates.

In this work, a facile ion-pairing strategy for asymmetric synthesis of optically active negatively charged chiral metal nanoparticles using chiral ammonium cations is demonstrated. A new thiolated chiral three-concentric-shell cluster, [Ag28Cu12(SR)24]4–, was first synthesized as a racemic mixture and characterized by single-crystal X-ray structure determination. Mass spectrometric measurements revealed relatively strong ion-pairing interactions between the anionic nanocluster and ammonium cations. Inspired by this observation, the as-prepared racemic mixture was separated into enantiomers by employing chiral quaternary ammonium salts as chiral resolution agents. Subsequently, direct asymmetric synthesis of optically active enantiomers of [Ag28Cu12(SR)24]4– was achieved by using appropriate chiral ammonium cations (such as N-benzylcinchoninium vs N-benzylcinchonidinium) in the cluster synthesis. These simple strategies, ion-pairing enantioseparation and direct asymmetric synthesis using chiral counterion...

An effective strategy is developed to synthesize high-nuclearity Cu clusters, [Cu53 (RCOO)10 (C≡CtBu)20 Cl2 H18 ]+ (Cu53 ), which is the largest CuI /Cu0 cluster reported to date. Cu powder and Ph2 SiH2 are employed as the reducing agents in the synthesis. As revealed by single-crystal diffraction, Cu53 is arranged as a four-concentric-shell Cu3 @Cu10 Cl2 @Cu20 @Cu20 structure, possessing an atomic arrangement of concentric M12 icosahedral and M20 dodecahedral shells which popularly occurs in Au/Ag nanoclusters. Surprisingly, Cu53 can be dissolved in diethyl ether and spin coated to form uniform nanoclusters film on organolead halide perovskite. The cluster film can subsequently be converted into high-quality CuI film via in situ iodination at room temperature. The as-fabricated CuI film is an excellent hole-transport layer for fabricating highly stable CuI-based perovskite solar cells (PSCs) with 14.3 % of efficiency.

An effective strategy is developed to synthesize high-nuclearity Cu clusters, [Cu

This paper reports co-crystallization of two atomically precise, different-size ligand-stabilized nanoclusters, a spherical (AuAg)267(SR)80 and a smaller trigonal-prismatic (AuAg)45(SR)27(PPh3)6 in 1:1 ratio, characterized fully by X-ray crystallographic analysis (SR = 2,4-SPhMe2). The larger cluster has a four concentric-shell icosahedral structure of Ag@M12@M42@M92@Ag120(SR)80 (M = Au or Ag) with the inner-core M147 icosahedron observed here for metal nanoparticles. The cluster has an open electron shell of 187 delocalized electrons, fully metallic, plasmonic behavior, and a zero HOMO-LUMO energy gap. The smaller cluster has an 18-electron shell closing, a notable HOMO-LUMO energy gap and a molecule-like optical spectrum. This is the first direct demonstration of the simultaneous presence of competing effects (closing of atom vs. electron shells) in nanocluster synthesis and growth, working together to form a co-crystal of different-sized clusters. This observation suggests a strategy that may be helpful in the design of other nanocluster systems via co-crystallization., Atomic shell closure and electronic shell closure are generally considered to be competing effects in stabilizing magic-sized metal nanoclusters. Here, the authors show, by co-crystallizing two differently-sized clusters, that both mechanisms can work concurrently during magic cluster synthesis.

A general method, using mixed ligands (here diphosphines and thiolates) is devised to turn an achiral metal cluster, Au

Gold-catalyzed intermolecular alkyne oxidation by an N–O bond oxidant has proven to be a powerful method in organic synthesis during the past decade, because this approach would enable readily available alkynes as precursors in generating α-oxo gold carbenes. Among those, gold-catalyzed oxidative cyclization of dialkynes has received particular attention as this chemistry offers great potential to build structurally complex cyclic molecules. However, these alkyne oxidations have been mostly limited to noble metal catalysts, and, to our knowledge, non-noble metal-catalyzed reactions such as diyne oxidations have not been reported. Herein, we disclose a copper-catalyzed oxidative diyne cyclization, allowing the facile synthesis of a wide range of valuable pyrrolo[3,4-c]quinolin-1-ones. Interestingly, by employing the same starting materials, the gold-catalyzed cascade cyclization leads to the divergent formation of synthetically useful pyrrolo[2,3-b]indoles. Furthermore, the proposed mechanistic rationale for these cascade reactions is strongly supported by both control experiments and theoretical calculations., Fused N-heterocycles are structural motifs observed in natural products and bioactive compounds. Here, the authors developed divergent copper- and gold-catalyzed oxidative cyclizations of diynes to two types of tricyclic N-heterocycles and rationalized the product selectivity by theoretical calculations.

Understanding the nucleation and growth pathways of nanocrystallites allows precise control of the size and shape of functional crystalline nanomaterials of importance in nanoscience and nanotechnology. This paper provides a detailed analysis of the stereochemical and electronic requirements of three series of nanoclusters based on face-centered cubes (fcc) as the basic building blocks, namely, 1-, 2-, and 3-D assemblages of fcc to form superrods (n), supersquares (n

By using ethylene glycol and monocarboxylic acid as surface ligands, a series of cyclic Ti-oxo clusters (CTOC) with permanent microporosity are successfully synthesized. With a cyclic {Ti32O16} backbone made of eight connected Ti4 tetrahedral cages that are arranged in a zigzag fashion, the clusters have a “donut” shape with an inner diameter of 8.3 A, outer diameter of 26.9 A and height of 10.4 A. While both inner and outer walls of the “donut” clusters are modified by double-deprotonated ethylene glycolates, their upper and lower surfaces are bound by carboxylates and mono-deprotonated ethylene glycolates. The clusters are readily packed into one-dimensional tubes which are further arranged in two different modes into crystalline microporous solids with surface areas over 660 m2 g−1, depending on the surface carboxylates. The solid with olefin-bearing carboxylates exhibits a superior CO2 adsorption capacity of 40 cm3 g−1 at 273 K under 1 atm. Moreover, the mono-deprotonated ethylene glycolates on the clusters are demonstrated to be highly exchangeable by other alcohols, providing a nice platform for creating microporous solids or films with a wide variety of surface functionalities.

A series of all-thiol stabilized bimetallic Au-Cu nanoclusters, [Au(12+n)Cu32(SR)(30+n)](4-) (n = 0, 2, 4, 6 and SR = SPhCF3), are successfully synthesized and characterized by X-ray single-crystal analysis and density functional theory (DFT) calculations. Each cluster consists of a Keplerate two-shell Au12@Cu20 core protected by (6 - n) units of Cu2(SR)5 and n units of Cu2Au(SR)6 (n = 0, 2, 4, 6) motifs on its surface. The size and structural evolution of the clusters is atomically controlled by the Au precursors and countercations used in the syntheses. The clusters exhibit similar optical absorption properties that are not dependent on the number of surface Cu2Au(SR)6 units. Although DFT suggests an electronic structure with an 18-electron superatom shell closure, the clusters display different thermal stabilities. [Au(12+n)Cu32(SR)(30+n)](4-) clusters with n = 0 and 2 are more stable than those with n = 4 and 6. Moreover, an oxidation product of the clusters, [Au13Cu12(SR)20](4-), is structurally identified to gain insight into how the clusters are oxidized.

Demonstrated herein are the preparation and crystallographic characterization of the family of fcc silver nanoclusters from Nichol’s cube to Rubik’s cube and beyond via ligand-control (thiolates and phosphines in this case). The basic building block is our previously reported fcc cluster [Ag14(SPhF2)12(PPh3)8] (1). The metal frameworks of [Ag38(SPhF2)26(PR′3)8] (22) and [Ag63(SPhF2)36(PR′3)8]+ (23), where HSPhF2 = 3,4-difluorothiophenol and R′ = alkyl/aryl, are composed of 2 × 2 = 4 and 2 × 2 × 2 = 8 metal cubes of 1, respectively. All serial clusters share similar surface structural features. The thiolate ligands cap the six faces and the 12 edges of the cube (or half cube) while the phosphine ligands are terminally bonded to its eight corners. On the basis of the analysis of the crystal structures of 1, 22, and 23, we predict the next “cube of cubes” to be Ag172(SR)72(PR′3)8] (33), in the evolution of growth of this cluster sequence.

In this work, a facile ion-pairing strategy for asymmetric synthesis of optically active negatively charged chiral metal nanoparticles using chiral ammonium cations is demonstrated. A new thiolated chiral three-concentric-shell cluster, [Ag

During the past two years, the introduction of DMSO has revolutionized the fabrication of high-quality pervoskite MAPbI3 (MA = CH3NH3) films for solar cell applications. In the developed DMSO process, the formation of (MA)2Pb3I8·2DMSO (shorted as Pb3I8) has well recognized as a critical factor to prepare high-quality pervoskite films and thus accomplish excellent performances in perovskite solar cells. However, Pb3I8 is an I-deficient intermediate and must further react with methylammonium iodide (MAI) to be fully converted into MAPbI3. By capturing and solving the molecular structures of several intermediates involved in the fabrication of perovskite films, we report in this work that the importance of DMSO is NOT due to the formation of Pb3I8. The use of different PbI2-DMSO ratios leads to two different structures of PbI2-DMSO precursors (PbI2·DMSO and PbI2·2DMSO), thus dramatically influencing the quality of fabricated perovskite films. However, such an influence can be minimized when the PbI2-DMSO precursor films are thermally treated to create mesoporous PbI2 films before reacting with MAI. Such a development makes the fabrication of high-quality pervoskite films highly reproducible without the need to precisely control the PbI2:DMSO ratio. Moreover, the formation of ionic compound (MA)4PbI6 is observed when excess MAI is used in the preparation of perovskite film. This I-rich phase heavily induces the hysteresis in PSCs, but is readily removed by isopropanol treatment. On the basis of all these findings, we develop a new effective protocol to fabricate high-performance PSCs. In the new protocol, high-quality perovskite films are prepared by simply treating the mesoporous PbI2 films (made from PbI2-DMSO precursors) with an isopropanol solution of MAI, followed by isopropanol washing. The best efficiency of fabricated MAPbI3 PSCs is up to 19.0%. As compared to the previously reported DMSO method, the devices fabricated by the method reported in this work display narrow efficiency distributions in both forward and reverse scans. And the efficiency difference between forward and reverse scans is much smaller.

Determining the structures of nanoparticles at atomic resolution is vital to understand their structure–property correlations. Large metal nanoparticles with core diameter beyond 2 nm have, to date, eluded characterization by single-crystal X-ray analysis. Here we report the chemical syntheses and structures of two giant thiolated Ag nanoparticles containing 136 and 374 Ag atoms (that is, up to 3 nm core diameter). As the largest thiolated metal nanoparticles crystallographically determined so far, these Ag nanoparticles enter the truly metallic regime with the emergence of surface plasmon resonance. As miniatures of fivefold twinned nanostructures, these structures demonstrate a subtle distortion within fivefold twinned nanostructures of face-centred cubic metals. The Ag nanoparticles reported in this work serve as excellent models to understand the detailed structure distortion within twinned metal nanostructures and also how silver nanoparticles can span from the molecular to the metallic regime., The structure of nanoparticles strongly influences their properties. Here, the authors use single crystal X-ray diffraction to resolve the crystal structures of Ag136 and Ag374 nanoparticles, enabling the observation of local structure distortion and the lower size limit of surface plasmon resonance.

A green gold-cluster, Au30S(StBu)18, was successfully prepared in high yield and crystallographically characterized. Each cluster consists of an Au22 core capped by a mixed layer of staple Au-thiolate units, bridging thiolates and a μ3-S2−.

A green gold-cluster, Au30S(StBu)18, was successfully prepared in high yield and crystallographically characterized. Each cluster consists of an Au22 core capped by a mixed layer of staple Au-thiolate units, bridging thiolates and a μ3-S(2-).

A series of all-thiol stabilized bimetallic Au-Cu nanoclusters, [Au(12+n)Cu32(SR)(30+n)](4-) (n = 0, 2, 4, 6 and SR = SPhCF3), are successfully synthesized and characterized by X-ray single-crystal analysis and density functional theory (DFT) calculations. Each cluster consists of a Keplerate two-shell Au12@Cu20 core protected by (6 - n) units of Cu2(SR)5 and n units of Cu2Au(SR)6 (n = 0, 2, 4, 6) motifs on its surface. The size and structural evolution of the clusters is atomically controlled by the Au precursors and countercations used in the syntheses. The clusters exhibit similar optical absorption properties that are not dependent on the number of surface Cu2Au(SR)6 units. Although DFT suggests an electronic structure with an 18-electron superatom shell closure, the clusters display different thermal stabilities. [Au(12+n)Cu32(SR)(30+n)](4-) clusters with n = 0 and 2 are more stable than those with n = 4 and 6. Moreover, an oxidation product of the clusters, [Au13Cu12(SR)20](4-), is structurally identified to gain insight into how the clusters are oxidized.

With the incorporation of Pd or Pt atoms, thiolated Ag-rich 25-metal-atom nanoclusters were successfully prepared and structurally characterized for the first time. With a composition of [PdAg24(SR)18](2-) or [PtAg24(SR)18](2-), the obtained 25-metal-atom nanoclusters have a metal framework structure similar to that of widely investigated Au25(SR)18. In both clusters, a M@Ag12 (M = Pd, Pt) core is capped by six distorted dimeric -RS-Ag-SR-Ag-SR- units. However, the silver-thiolate overlayer gives rise to a geometric chirality at variance to Au25(SR)18. The effect of doping on the electronic structure was studied through measured optical absorption spectra and ab initio analysis. This work demonstrates that modulating electronic structures by transition-metal doping is expected to provide effective means to manipulate electronic, optical, chemical, and catalytic properties of thiolated noble metal nanoclusters.