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The structural transformation of high-nuclearity silver clusters from one to another induced by specific stimuli is of scientific significance in terms of both cluster synthesis and reactivity. Herein, we report two silver-thiolate clusters, [Mo 6 O 22 @Ag 44 ] and [Mo 8 O 28 @Ag 50 ], which are templated by isopolymolybdates inside and covered by i PrS − and PhCOO − ligands on the surfaces. Amazingly, the [Mo 8 O 28 @Ag 50 ] can be transformed from [Mo 6 O 22 @Ag 44 ] by adding PhCOOH which increases the degree of condensation of molybdates template from Mo 6 O 22 8- to Mo 8 O 28 8- , then enlarging the outer silver shell from Ag 44 to Ag 50 . The evolution of solution species revealed by time-dependent electrospray ionization mass spectrometry (ESI-MS) suggests a breakage-growth-reassembly (BGR) transformation mechanism. These results not only provide a combined assembly strategy (anion-template + induced transformation) for the synthesis of silver-thiolate clusters but also help us to better understand the complex transformation process underpinning the assembly system. Understanding how one metal nanocluster transforms into another is of synthetic and fundamental importance. Here, the authors use mass spectrometry to reveal an acid-induced structural transformation between two Ag clusters that proceeds via a breakage-growth-reassembly mechanism.

High-nuclearity silver clusters are appealing synthetic targets for their remarkable structures, but most are isolated serendipitously. We report here six giant silver-thiolate clusters mediated by solvents, which not only dictate the formation of an octahedral Ag 6 4+ kernel, but also influence the in situ-generated Mo-based anion templates. The typical sevenfold symmetric silver nanowheels show a hierarchical cluster-in-cluster structure that comprises an outermost Ag 56 shell and an inner Ag 6 4+ kernel in the centre with seven MoO 4 2− anion templates around it. Electrospray ionization mass spectrometry analyses reveal the underlying rule for the formation of such unique silver nanowheels. This work establishes a solvent–intervention approach to construct high-nuclearity silver clusters in which both the formation of octahedral Ag 6 4+ kernel and in situ generation of various Mo-based anion templates can be simultaneously controlled. High-nuclearity silver clusters are appealing synthetic targets for their remarkable structures, but most are isolated serendipitously. Here, the authors describe the rational use of solvents to form cluster-in-cluster silver nanowheels, which comprise an octahedral Ag 6 4+ core surrounded by a Ag 56 cage of unusual seven-fold symmetry.

Owing to its high thermal and electrical conductivities, its ductility and its overall non-toxicity 1 – 3 , copper is widely used in daily applications and in industry, particularly in anti-oxidation technologies. However, many widespread anti-oxidation techniques, such as alloying and electroplating 1 , 2 , often degrade some physical properties (for example, thermal and electrical conductivities and colour) and introduce harmful elements such as chromium and nickel. Although efforts have been made to develop surface passivation technologies using organic molecules, inorganic materials or carbon-based materials as oxidation inhibitors 4 – 12 , their large-scale application has had limited success. We have previously reported the solvothermal synthesis of highly air-stable copper nanosheets using formate as a reducing agent 13 . Here we report that a solvothermal treatment of copper in the presence of sodium formate leads to crystallographic reconstruction of the copper surface and formation of an ultrathin surface coordination layer. We reveal that the surface modification does not affect the electrical or thermal conductivities of the bulk copper, but introduces high oxidation resistance in air, salt spray and alkaline conditions. We also develop a rapid room-temperature electrochemical synthesis protocol, with the resulting materials demonstrating similarly strong passivation performance. We further improve the oxidation resistance of the copper surfaces by introducing alkanethiol ligands to coordinate with steps or defect sites that are not protected by the passivation layer. We demonstrate that the mild treatment conditions make this technology applicable to the preparation of air-stable copper materials in different forms, including foils, nanowires, nanoparticles and bulk pastes. We expect that the technology developed in this work will help to expand the industrial applications of copper. High oxidation resistance, without degradation of thermal or electrical conductivity, is achieved in copper using surface modification by a solvothermal or electrochemical treatment with sodium formate and formation of a thin surface coordination layer.

Thiacalix[4]arenes as a family of promising ligands have been widely used to construct polynuclear metal clusters, but scarcely employed in silver nanoclusters. Herein, an anion-templated Ag 88 nanocluster (SD/Ag88a) built from p -tert-butylthiacalix[4]arene (H 4 TC4A) is reported. Single-crystal X-ray diffraction reveals that C 4 -symmetric SD/Ag88a resembles a metal-organic super calix comprised of eight TC4A 4− as walls and 88 silver atoms as base, which can be deconstructed to eight [CrO 4 @Ag 11 (TC4A)(EtS) 4 (OAc)] secondary building units arranged in an annulus encircling a CrO 4 2− in the center. Local and global anion template effects from chromates are individually manifested in SD/Ag88a. The solution stability and hierarchical assembly mechanism of SD/Ag88a are studied by using electrospray mass spectrometry. The Ag 88 nanocluster represents the highest nuclearity metal cluster capped by TC4A 4− . This work not only exemplify the specific macrocyclic effects of TC4A 4− in the construction of silver nanocluster but also realize the shape heredity of TC4A 4− to overall silver super calix. The assembly of giant silver clusters by using macrocylic multidentate ligand remains a challenge. Here, the authors synthesize a chromate-templated 88-nuclei silver super calix and reveal the role of anion templating effects and a hierarchical assembly mechanism.

Photocatalytic reduction of CO 2 is a promising approach to achieve solar-to-chemical energy conversion. However, traditional catalysts usually suffer from low efficiency, poor stability, and selectivity. Here we demonstrate that a large porous and stable metal-organic framework featuring dinuclear Eu(III) 2 clusters as connecting nodes and Ru(phen) 3 -derived ligands as linkers is constructed to catalyze visible-light-driven CO 2 reduction. Photo-excitation of the metalloligands initiates electron injection into the nodes to generate dinuclear {Eu(II)} 2 active sites, which can selectively reduce CO 2 to formate in a two-electron process with a remarkable rate of 321.9 μmol h −1  mmol MOF −1 . The electron transfer from Ru metalloligands to Eu(III) 2 catalytic centers are studied via transient absorption and theoretical calculations, shedding light on the photocatalytic mechanism. This work highlights opportunities in photo-generation of highly active lanthanide clusters stabilized in MOFs, which not only enables efficient photocatalysis but also facilitates mechanistic investigation of photo-driven charge separation processes. Solar-to-chemical CO 2 reduction provides a means to use light’s energy for CO 2 removal and upgrading to useful products, although this photochemical conversion is challenging. Here, authors construct a Europium-containing metal-organic framework that selectively converts CO 2 to formate with light.

The assembly of spherical fullerenes, or buckyballs, into single crystals for crystallographic identification often suffers from disordered arrangement. Here we show a chiral configuration of decapyrrylcorannulene that has a concave ‘palm’ of corannulene and ten flexible electron-rich pyrryl group ‘fingers’ to mimic the smart molecular ‘hands’ for self-adaptably cradling various buckyballs in a (+)hand-ball-hand(−) mode. As exemplified by crystallographic identification of 15 buckyball structures representing pristine, exohedral, endohedral, dimeric and hetero-derivatization, the pyrryl groups twist with varying dihedral angles to adjust the interaction between decapyrrylcorannulene and fullerene. The self-adaptable electron-rich pyrryl groups, susceptible to methylation, are theoretically revealed to contribute more than the bowl-shaped palm of the corannulene in holding buckyball structures. The generality of the present decapyrrylcorannulene host with flexible pyrryl groups facilitates the visualization of numerous unknown/unsolved fullerenes by crystallography and the assembly of the otherwise close-packed spherical fullerenes into two-dimensional layered structures by intercalation. The structures of fullerenes, or buckyballs, are often very difficult to resolve. Here, the authors describe a decapyrrylcorannulene host with ten flexible pyrryl groups that can efficiently co-crystallize with diverse fullerene derivatives in a ‘hand-ball-hand’ fashion, allowing crystallographic identification of commonly known types of fullerenes.

The exploration of artificial metal-peptide assemblies (MPAs) is one of the most exciting fields because of their great potential for simulating the dynamics and functionality of natural proteins. However, unfavorable enthalpy changes make forming discrete complexes with large and adaptable cavities from flexible peptide ligands challenging. Here, we present a strategy integrating metal-cluster building blocks and peptides to create chiral metal-peptide assemblies and get a family of enantiopure [ R-/S- Ni 3 L 2 ] n (n = 2, 3, 6) MPAs, including the R-/S- Ni 6 L 4 capsule, the S- Ni 9 L 6 trigonal prism, and the R-/S- Ni 18 L 12 octahedron cage. X-ray crystallography shows MPA formation reactions are highly solvent-condition-dependent, resulting in significant changes in ligand conformation and discrete cavity sizes. Moreover, we demonstrate that a structure transformation from Ni 18 L 12 to Ni 9 L 6 in the presence of benzopyrone molecules depends on the peptide conformational selection in crystallization. This work reveals that a metal-cluster building block approach enables facile bottom-up construction of artificial metal-peptide assemblies. The use of metal clusters to construct artificial protein-mimic structures with adaptable cavities has potential for simulating the dynamics and functionality of natural proteins. Here, the authors develop a family of chiral metal-peptide assemblies using {Ni3} clusters and flexible peptides, resulting in structures such as octahedral cages, trigonal prisms, and capsules.

The most stable fullerenes obey the isolated-pentagon rule (IPR): hexagons of carbon atoms entirely surround pentagons to minimize strain. Recently, some examples of fused-pentagon fullerenes have been reported and this Review summarizes current work to stabilize non-IPR fullerenes. The isolated pentagon rule (IPR) is now widely accepted as a general rule for determining the stability of all-carbon fullerene cages composed of hexagons and pentagons. Fullerenes that violate this rule have been deemed too reactive to be synthesized. The stabilization of non-IPR endohedral fullerenes depends on charge transfer from the encapsulated metal clusters (endoclusters) to fullerene cages, the electronic properties of empty all-carbon cages, the matching size and geometries of fullerene and endocluster, as well as the strong coordination of the metal ions to fused pentagons. The stability of non-IPR exohedral fullerenes can be rationalized primarily by both the 'strain-relief' and 'local-aromaticity' principles. This Review focuses on recent work on stabilization of non-IPR fullerenes, including theoretical and empirical principles, experimental methods, and molecular structures of fused-pentagon fullerenes characterized so far. The special chemical properties of non-IPR fullerenes that distinguish them from IPR-satisfying ones are also emphasized.

The construction of inorganic porous frameworks from discrete polyoxometalate (POM) units is a major research challenge. Herein, a three-dimensional (3D) all-inorganic porous structure {Mo 154 } n that consists of classic Mo 154 rings connected by Mo-O-Mo covalent bonds was synthesized. Interestingly, the proton conductivity of the 3D-{Mo 154 } n framework is 1.1×10 −2 S cm −1 at 22 °C and 100% relative humidity (RH), which is one of the highest proton conductivities reported thus far for POM-based conductive materials. Compared to the discrete {Mo 154 } cluster and 1D-{Mo 154 } n , the enhanced conductivity of 3D-{Mo 154 } n suggests that assembling POM-based all-inorganic porous frameworks is a promising method for designing proton-conductive materials.

Unlike traditional small molecule drugs, fullerene is an all-carbon nanomolecule with a spherical cage structure. Fullerene exhibits high levels of antiviral activity, inhibiting virus replication in vitro and in vivo. In this review, we systematically summarize the latest research regarding the different types of fullerenes investigated in antiviral studies. We discuss the unique structural advantage of fullerenes, present diverse modification strategies based on the addition of various functional groups, assess the effect of structural differences on antiviral activity, and describe the possible antiviral mechanism. Finally, we discuss the prospective development of fullerenes as antiviral drugs.