Abstract. The Fischer–Tropsch (FT) process facilitates the stepwise hydrogenation of carbon monoxide wherein liquid fuels are constructed from surface-boun

Stabilization of elusive aluminum(I) halides in the framework of an ambiphilic ligand is reported. The unique bonding situation at the trigonal-bipyramidal aluminum center is analyzed, and the coordi....

Of the three nitrogenase isozymes (Mo, V, and Fe-only), the Mo nitrogenase shows the highest selectivity for N2 vs. H+ reduction. Here, we study the reduction chemistry of a series of synthetic [MFe3S4] clusters and find that only those that contain large auxiliary metals bind N2 at Fe. These results support an electronic role for “heterometals” featuring diffuse orbitals in facilitating N2 binding at neighboring Fe sites.

Why is the Mo nitrogenase more adept at N2 reduction than its alternative nitrogenase counterparts (V and Fe-only)? To investigate this question, we undertook a comparative structural and spectroscopic analysis of synthetic [MoFe3S4] and [Fe4S4] clusters. We found differences in how the clusters distribute electron density, with the iron centers in the [MoFe3S4] clusters being better at backbonding to weakly π-acidic ligands. Such differences may account for the greater efficiency of the Mo nitrogenase.

Nitrenes are well-known reactive intermediates used to form a variety of nitrogen-containing molecules, but their reduced radical anions have remained inaccessible under ambient temperature. Here, a persistent nitrene can be converted into an isolable radical anion that features a non-Aufbau electronic configuration. This species acts as a nucleophilic nitrogen radical that forms new N–Se, N–Si, and N–C bonds under mild conditions.

Metal clusters are of broad interest across fields in that they possess unique properties making them appealing for a variety of applications; additionally, they provide fundamental understanding of t...

Hydrogen activation by stable carbenes is rare and typically proceeds through π-face, non-least-motion pathways. Now, a neutral σ0π2 carbene has been synthesized and shown to cleave H2 at room tempera...

Molecular complexes of iron in the rare +1 oxidation state have been shown to be efficient catalysts for industrially relevant chemical transformations, typically associated with the increasingly unsu...

A modular synthetic approach affords a series of cationic cobalt and manganese carbonyl half-sandwich complexes bearing onium-substituted diphosphacyclobutadienyl ligands. In this strategy, the onium....

Using a hydrocarbon-soluble Mg0 complex, the heavier tetrel elements silicon, germanium, tin and lead are reduced to their ultimate negative oxidation state −IV. Despite fulfilling the octet rule, tet...

Aromatic rings such as the ubiquitous π-ligand cyclopentadienide (C5H5−) adhere to the famous Hückel rule with their 4n+2 π cyclically delocalized electrons. Since the advent of stable Si–Si π-bonds i...

Low-valent aluminum chemistry continues to expand the boundaries of main-group reactivity, yet the selective generation and transfer of Al(II) fragments remain underexplored. Controlled Al(II) transfe...

A simple plugin that extends the eraser functionality of ChimeraX. It provides a cube, a cylinder and a custom shape eraser. The eraser tools are available in the Right Mouse toolbar. - TaminoCairo...

Compared with the wide variety of reports on carbon π-electron compounds, the silicon counterparts remain scarce because of the intrinsic preference of silicon to form σ-bonded compounds. In particula...

Aluminium redox catalysis is achieved with a low-valent aluminium species, carbazolylaluminylene, enabling cyclotrimerization of alkynes and producing diverse benzene derivatives.

The isolation of catenated nitrogen compounds is difficult, in part because these chains can readily lose nitrogen, creating a strong thermodynamic push towards decomposition. Now, a series of molecul...

Seventy years after the discovery of ferrocene, the first neutral bis(cyclopentadienyl)metal complex of copper has been synthesized: Cpttt2Cu, 1 (Cpttt = C5H2tBu3). Comparison of this compound and the...

Iron’s abundance motivates its use in sustainable catalyst systems that also offer complementary reactivity manifolds compared to precious metals. However, the challenging reduction of benchmark iron ...

Cubane-type iron–sulfur clusters (Fe4S4) are some of the most versatile metallocofactors and, as such, among multiple functions, primarily responsible for mediating challenging electron transfers (ETs...

To harness the unique luminescent and magnetic properties of lanthanides, precise control over their coordination sphere is essential, whether to minimize deactivation processes or maximize magnetic a...

How much longer will glaciers survive? A new study from ETH Zurich researchers offers the first detailed projection of how many glaciers could vanish by 2100 due to global warming – and why regions su...

Imido complexes of high-spin 3d metals can feature N subvalency, wherein configurations with hole character at N contribute significantly to the ground state electronic structure. Reported herein are the synthesis and characterization of a series of Fe–S cluster terminal imido complexes isolated in four charge states, [(IMes)3Fe4S4(NAr)]n (IMes, 1,3-dimesitylimidazol-2-ylidene; Ar = 2,4,6-tri-tert-butylphenyl; n = 1–, 0, 1+, 2+), in which the weak, trigonal ligand field of the sulfides enforces high-spin configurations at the Fe sites. It is shown that whereas the ground states of the anionic and neutral members of the series feature dominant imide ([NAr]2–) character, the mono- and dicationic clusters have significant imidyl ([NAr]•–) and/or triplet nitrene (3NAr) character. This was demonstrated experimentally using variable-temperature 1H NMR spectroscopy to reveal the spin topology of the [Fe(NAr)] unit across the series. Additional structural, spectroscopic, and computational analysis revealed the extent to which electron density changes occur at the imido-bound Fe versus the peripheral Fe sites. These results establish the preference for high-spin Fe-imido sites in Fe–S clusters and the possibility for such sites to have multiconfigurational electronic structures with imide, imidyl, and/or nitrene character.

We herein present a comprehensive analysis of the oxidation-state-dependence of the 57Fe partial vibrational density of states (PVDOS), measured using nuclear resonance vibrational spectroscopy (NRVS)...

Elucidating the nature of the metallocofactors in nitrogenase enzymes, and preparing synthetic analogues of these clusters, is a classic target for bioinorganic chemists. Now the transformation of [Fe...