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Solid-state auride salts featuring the negatively charged Au – ion are known to be stable in the presence of alkali metal counterions. While such electron-rich species might be expected to be nucleophilic (in the same manner as I – , for example), their instability in solution means that this has not been verified experimentally. Here we report a two-coordinate gold complex (NON)AlAuP t Bu 3 (where NON is the chelating tridentate ligand 4,5-bis(2,6-diisopropylanilido)-2,7-di- tert -butyl-9,9-dimethylxanthene) that features a strongly polarized bond, Au δ – –Al δ + . This is synthesized by reaction of the potassium aluminyl compound [K{Al(NON)}] 2 with t Bu 3 PAuI. Computational studies of the complex, including quantum theory of atoms in molecules charge analysis, imply a charge at gold (−0.82) that is in line with the relative electronegativities of the two metals (Au: 2.54; Al: 1.61 on the Pauling scale). Consistently, the complex is found to act as a nucleophilic source of gold, reacting with diisopropylcarbodiimide and CO 2 to give the Au–C bonded insertion products (NON)Al(X 2 C)AuP t Bu 3 (X = N i Pr, 4 ; X = O, 5 ). A two-coordinate monovalent gold complex that features a highly polarized aluminium–gold covalent bond, Al δ + –Au δ− , has been synthesized using a very strongly electron-donating aluminyl ligand. In solution, the complex reacts as a nucleophilic source of gold towards heteroallenes such as carbodiimides and CO 2 .

Phosphanorcaradienes are an appealing class of phosphorus compounds that can serve as synthons of transient phosphinidenes. However, the synthesis of such species is a formidable task owing to their intrinsic high reactivity. Herein we report straightforward synthesis, characterization and reactivity studies of a phosphanorcaradiene, in which one of the benzene rings in the flanking fluorenyl substituents is intramolecularly dearomatized through attachment to the phosphorus atom. It is facilely obtained by the reduction of phosphorus(III) dichloride precursor with potassium graphite. Despite being thermally robust, it acts as a synthetic equivalent of a transient phosphinidene. It reacts with trimethylphosphine and isonitrile to yield phosphanylidene-phosphorane and 1-phospha-3-azaallene, respectively. When it is treated with one and two molar equivalents of azide, iminophosphane and bis(imino)phosphane are isolated, respectively. Moreover, it is capable of activating ethylene and alkyne to afford [1 + 2] cycloaddition products, as well as oxidative cleavage of Si–H and N–H bonds to yield secondary phosphines. All the reactions proceed smoothly at room temperature without the presence of transition metals. The driving force for these reactions is most likely the high ring-constraint of the three-membered PC 2 ring and recovery of the aromaticity of the benzene ring. Phosphanorcaradienes can serve as synthons for transient phosphinidene but the synthesis remains challenging. Here, the authors report a synthesis protocol for a phosphanorcaradiene, in which one of the benzene rings is intramolecularly dearomatized through attachment to the phosphorus atom.

Chemists have spent over a hundred years trying to make ambient temperature/pressure catalytic systems that can convert atmospheric dinitrogen into ammonia or directly into amines. A handful of successful d-block metal catalysts have been developed in recent years, but even binding of dinitrogen to an f-block metal cation is extremely rare. Here we report f-block complexes that can catalyse the reduction and functionalization of molecular dinitrogen, including the catalytic conversion of molecular dinitrogen to a secondary silylamine. Simple bridging ligands assemble two actinide metal cations into narrow dinuclear metallacycles that can trap the diatom while electrons from an externally bound group 1 metal, and protons or silanes, are added, enabling dinitrogen to be functionalized with modest but catalytic yields of six equivalents of secondary silylamine per molecule at ambient temperature and pressure.Metallacycles formed from two large, under-coordinated actinide MIV cations and two rigid arene-bridged aryloxide ligands are capable of binding dinitrogen inside their cavity. These f-block complexes can catalyse the reduction and functionalization of dinitrogen as well as the catalytic conversion of molecular dinitrogen to a secondary silylamine.

Hydrogen production through electrochemical process is at the heart of key renewable energy technologies including water splitting and hydrogen fuel cells. Despite tremendous efforts, exploring cheap, efficient and durable electrocatalysts for hydrogen evolution still remains as a great challenge. Here we synthesize a nickel–carbon-based catalyst, from carbonization of metal-organic frameworks, to replace currently best-known platinum-based materials for electrocatalytic hydrogen evolution. This nickel-carbon-based catalyst can be activated to obtain isolated nickel atoms on the graphitic carbon support when applying electrochemical potential, exhibiting highly efficient hydrogen evolution performance with high exchange current density of 1.2 mA cm −2 and impressive durability. This work may enable new opportunities for designing and tuning properties of electrocatalysts at atomic scale for large-scale water electrolysis. There is tremendous ongoing effort in the development of electrocatalysts for hydrogen evolution. Here, the authors report that single nickel atoms dispersed on graphitic supports are formed by carbonization of metal-organic frameworks and that they are highly active hydrogen evolution catalysts.

The toxicity of lead perovskite hampers the commercialization of perovskite-based photovoltaics. While tin perovskite is a promising alternative, the facile oxidation of tin(II) to tin(IV) causes a high density of defects, resulting in lower solar cell efficiencies. Here, we show that tin(0) nanoparticles in the precursor solution can scavenge tin(IV) impurities, and demonstrate that this treatment leads to effectively tin(IV)-free perovskite films with strong photoluminescence and prolonged decay lifetimes. These nanoparticles are generated by the selective reaction of a dihydropyrazine derivative with the tin(II) fluoride additive already present in the precursor solution. Using this nanoparticle treatment, the power conversion efficiency of tin-based solar cells reaches 11.5%, with an open-circuit voltage of 0.76 V. Our nanoparticle treatment is a simple and broadly effective method that improves the purity and electrical performance of tin perovskite films. Tin based perovskites are easily oxidized, which generates large density of defects and compromised the solar cell efficiency. Here Nakamura et al. add metallic tin nanoparticles in the precursor solution to suppress tin (IV) impurities and enable high efficiency tin based perovskite solar cells.

Nitrogen (N 2 ) fixation by nature, which is a crucial process for the supply of bio-available forms of nitrogen, is performed by nitrogenase. This enzyme uses a unique transition-metal–sulfur–carbon cluster as its active-site co-factor ([( R -homocitrate)MoFe 7 S 9 C], FeMoco) 1 , 2 , and the sulfur-surrounded iron (Fe) atoms have been postulated to capture and reduce N 2 (refs. 3 – 6 ). Although there are a few examples of synthetic counterparts of the FeMoco, metal–sulfur cluster, which have shown binding of N 2 (refs. 7 – 9 ), the reduction of N 2 by any synthetic metal–sulfur cluster or by the extracted form of FeMoco 10 has remained elusive, despite nearly 50 years of research. Here we show that the Fe atoms in our synthetic [Mo 3 S 4 Fe] cubes 11 , 12 can capture a N 2 molecule and catalyse N 2 silylation to form N(SiMe 3 ) 3 under treatment with excess sodium and trimethylsilyl chloride. These results exemplify the catalytic silylation of N 2 by a synthetic metal–sulfur cluster and demonstrate the N 2 -reduction capability of Fe atoms in a sulfur-rich environment, which is reminiscent of the ability of FeMoco to bind and activate N 2 . Iron atoms in a synthetic metal–sulfur cluster can capture nitrogen and catalyse its silylation, demonstrating successful nitrogen reduction by iron atoms in a sulfur-rich environment.

Transition-metal complexes are widely used in the physical and biological sciences. They have essential roles in catalysis, synthesis, materials science, photophysics and bioinorganic chemistry. Our understanding of transition-metal complexes originates from Alfred Werner’s realization that their three-dimensional shape influences their properties and reactivity 1 , and the intrinsic link between shape and electronic structure is now firmly underpinned by molecular-orbital theory 2 – 5 . Despite more than a century of advances in this field, the geometries of transition-metal complexes remain limited to a few well-understood examples. The archetypal geometries of six-coordinate transition metals are octahedral and trigonal prismatic, and although deviations from ideal bond angles and bond lengths are frequent 6 , alternative parent geometries are extremely rare 7 . The hexagonal planar coordination environment is known, but it is restricted to condensed metallic phases 8 , the hexagonal pores of coordination polymers 9 , or clusters that contain more than one transition metal in close proximity 10 , 11 . Such a geometry had been considered 12 , 13 for [Ni(P t Bu) 6 ]; however, an analysis of the molecular orbitals suggested that this complex is best described as a 16-electron species with a trigonal planar geometry 14 . Here we report the isolation and structural characterization of a simple coordination complex in which six ligands form bonds with a central transition metal in a hexagonal planar arrangement. The structure contains a central palladium atom surrounded by three hydride and three magnesium-based ligands. This finding has the potential to introduce additional design principles for transition-metal complexes, with implications for several scientific fields. A six-coordinate transition-metal complex with a hexagonal planar geometry is isolated and characterized.

The electroreduction of water for sustainable hydrogen production is a critical component of several developing clean-energy technologies, such as water splitting and fuel cells. However, finding a cheap and efficient alternative catalyst to replace currently used platinum-based catalysts is still a prerequisite for the commercialization of these technologies. Here we report a robust and highly active catalyst for hydrogen evolution reaction that is constructed by in situ growth of molybdenum disulfide on the surface of cobalt diselenide. In acidic media, the molybdenum disulfide/cobalt diselenide catalyst exhibits fast hydrogen evolution kinetics with onset potential of −11 mV and Tafel slope of 36 mV per decade, which is the best among the non-noble metal hydrogen evolution catalysts and even approaches to the commercial platinum/carbon catalyst. The high hydrogen evolution activity of molybdenum disulfide/cobalt diselenide hybrid is likely due to the electrocatalytic synergistic effects between hydrogen evolution-active molybdenum disulfide and cobalt diselenide materials and the much increased catalytic sites. There is substantial research into new catalysts for electroreduction of water. Here, the authors report a robust and active molybdenum disulfide/cobalt diselenide hydrogen evolution catalyst with onset potential of 11 mV and Tafel slope of 36 mV per decade, approaching the activity of platinum.

Layered molybdenum disulfide has demonstrated great promise as a low-cost alternative to platinum-based catalysts for electrochemical hydrogen production from water. Research effort on this material has focused mainly on synthesizing highly nanostructured molybdenum disulfide that allows the exposure of a large fraction of active edge sites. Here we report a promising microwave-assisted strategy for the synthesis of narrow molybdenum disulfide nanosheets with edge-terminated structure and a significantly expanded interlayer spacing, which exhibit striking kinetic metrics with onset potential of −103 mV, Tafel slope of 49 mV per decade and exchange current density of 9.62 × 10 −3 mA cm −2 , performing among the best of current molybdenum disulfide catalysts. Besides benefits from the edge-terminated structure, the expanded interlayer distance with modified electronic structure is also responsible for the observed catalytic improvement, which suggests a potential way to design newly advanced molybdenum disulfide catalysts through modulating the interlayer distance. Layered molybdenum disulfide is a promising hydrogen evolution catalyst. Here, the authors report a strategy for synthesizing molybdenum disulfide nanosheets with edge-terminated structure and a significantly expanded interlayer spacing and demonstrate their enhanced catalytic activity.

Exploratory synthesis in new chemical spaces is the essence of solid-state chemistry. However, uncharted chemical spaces can be difficult to navigate, especially when materials synthesis is challenging. Nitrides represent one such space, where stringent synthesis constraints have limited the exploration of this important class of functional materials. Here, we employ a suite of computational materials discovery and informatics tools to construct a large stability map of the inorganic ternary metal nitrides. Our map clusters the ternary nitrides into chemical families with distinct stability and metastability, and highlights hundreds of promising new ternary nitride spaces for experimental investigation—from which we experimentally realized seven new Zn- and Mg-based ternary nitrides. By extracting the mixed metallicity, ionicity and covalency of solid-state bonding from the density functional theory (DFT)-computed electron density, we reveal the complex interplay between chemistry, composition and electronic structure in governing large-scale stability trends in ternary nitride materials.