Main group chemistry

Bis(N-heterocyclic carbene)-borylene complexes are capable of capturing and functionalizing CO₂, but stable single-site-boron-carbon dioxide adducts are rarely reported. Here, the authors report the synthesis of a stable borylene-CO₂ complex as well as the functionalization of the captured CO₂.

The chemistry of carbon monoxide (CO) as a ligand has evolved significantly and transition-metal carbonyl complexes have been widely used as catalysts in many important catalytic processes. Here the authors comment on the recent progress of main-group element carbonyl complexes along with their future prospects.

The chemistry of stable low oxidation state group 2 metal compounds was initiated in 2007 and has since expanded rapidly, yielding many surprises. Here the author outlines advances in the field and discusses some of the open questions and challenges that remain to be answered in coming years.

The Hückel rule defines that monocyclic and planar conjugated systems containing [4n + 2] π electrons are aromatic. Here, the authors highlight boron species that feature a globally 4n π system, defying the Hückel rule, but nonetheless exhibit aromaticity.

Tetrylones show unique electronic properties and display potantial as soluble molecular allotropes, but until now, the chemistry of Tetrylone homologs remains underexplored. Here, the authors describe the synthesis of a family of antimony(I) and bismuth(I) cations supported by a bis silylene ligand and explore their reactivity.

Group 10 metal species are commonly used to activate Si–H and Si–Si bonds, but their preferred reactivity towards Si–H vs Si–Si activation is poorly understood. Here, Pt(0) species are shown to selectively activate the Si–H bonds in a linear tetrasilane, whereas Pd(0) preferentially activates the Si–Si bonds.

The stabilization of low-coordinate boron radicals is challenging, as they tend to form strong chemical bonds. Here the authors report the isolation and structural characterization of a dicoordinate boron radical featuring a π-donating amino and a π-accepting carbene ligand.

High pressure can modify the chemical properties of the elements, giving rise to exotic bonding. Here the authors report the prediction of a nitrogen-rich iodine nitride compound IN₆ where the iodine atom has an unusual twelve-fold coordination, stable above 100 GPa.

Asymmetrically substituted phosphine ligands play a decisive role in catalysis, but their synthesis is rather challenging and often involves hazardous chemicals such as PCl₃ or PH₃. Here, the authors report the one-pot preparation of asymmetric phosphines from white phosphorus via a pentaphosphaferrocene based modular system, in which the transition metal complex can be reused.

Unlike other halogen atoms, the ability for fluorine to exist in a [C–X–C]⁺ connectivity pattern has only been shown in spectroscopic studies. Here the authors present a single crystal structure of a fluoronium cation, characterized by X-ray diffraction.

Chemical reduction of alkali cations to their metals is extremely challenging. Here, the authors synthesized a series of redox-active borate anions stabilized by bipyridine ligands which can reduce lithium ions generating elemental lithium metal and borate radicals.

Bis(arylimino)acenaphthene ligands were recognized as robust scaffolds for metal complexes decades ago, but their redox non-innocence as well as their potential to mediate electro- or photo-catalysis remain subjects of active research. Here, the authors review the synthesis and properties of these poly-aromatic diimine ligands complexed to nominally redox-innocent p-block elements.

The activation of very inert small molecules generally requires highly reactive activating species, but the high energy of these species makes their regeneration, and thus also catalytic turnover of the reaction, difficult to achieve. Here, the authors highlight the formidable challenge of overcoming the tradeoff between activating power and catalytic turnover in the context of main-group ambiphiles.

Here the authors demonstate that counter to expectation provided by the relevant standard reduction potentials, a chloroberyllate, [{SiNDipp}BeClLi]2, reacts with the group 1 elements (M = Na, K, Rb, Cs) to provide the respective heavier alkali metal analogues, [{SiNDipp}BeClM]2.

Understanding the intermetallic synergy and the structure-performances relationships of catalysts remains challenging. Here, the authors demonstrate a relationship between both the rates, selectivity and the s-block metal acidity in a series of heterodinuclear catalysts based on Co(III) in combination with alkali and alkaline earth metals for three different polymerization reactios.

Controlled atomic delivery is a desirable synthetic process. Here a germanium-substituted phenyl anion is shown to act as a germanium atom transfer reagent and demonstrated by the preparation of well-defined molecular germanium species.

Electrophilic borylation of sterically hindered arenes is a challenging transformation. Here, authors report a metal-free electrophilic C–H borylation of hindered arenes using a boron cluster reagent producing valuable aryl boronic esters.

Pepto-Bismol has been used to treat gastrointestinal disorders for over a century, yet the structure of its active ingredient is still under debate. Here, the authors apply electron crystallography to unveil the structure of bismuth subsalicylate.

The number of metal complexes featuring gold-germanium bonds is limited. Here the authors report the preparation of germylene-bridged digold complexes complexes and study their structure, bonding, and reactivity.

Stoichiometric carbon monoxide insertion processes leading to metal-formyl complexes are scarce, even for transition metals. Here, light is shed on the underexplored chemistry of beryllium hydrides leading to a stable example of a main group metal-formyl complex.

Frustrated Lewis pairs can be thermally revived from classical Lewis adducts, but the mechanism by which this occurs is not well understood. Here a combined experimental and theoretical study supports a pathway mediated by boron-jumping and dynamic conformational isomerization.

Halogen–sodium exchange reactions with neopentyl sodium provides access to a range of aryl and alkenyl organosodium compounds in situ, as an alternative to organolithium reagents.

Understanding the formation pathways of multimetallic clusters is essential to the progress of cluster research, but remains highly challenging. Here, time-dependent crystallization, mass spectrometry, and quantum chemical calculations are used to gain insight into the formation pathways of bismuth–tungsten carbonyl clusters.

Gaining insight on the structural transformations from atomic clusters to bulk materials is challenging. Here the authors synthesize a continuous cluster of germanium Ge₂₄⁴⁻, which can be viewed as two terminal Ge₉ units bridged via a Ge₆ central fragment, and characterize it by several techniques including X-ray diffraction; theoretical analysis indicates the presence of three aligned independent aromatic fragments.

Despite its electron deficiency, boron can form multiple bonds with a variety of elements, but such bonds between boron and main-group metal elements are relatively rare. Here, the authors characterize boron–lead multiple bonds in PbB₂O^- and PbB₃O₂^- produced by laser vaporization.

Ternary heterometallic clusters often display intriguing structures and bonding. Here the authors prepare four [Sn₂Sb₅]³⁻-based clusters stabilized by coordination of a transition metal ion; analysis of their electronic structure reveals that the resulting cluster displays globally aromatic or antiaromatic character depending on the transition metal ion.

Incorporating main group elements into amorphous porous organic polymers has enabled the fine tuning of the structures and properties of these materials. Here, the authors review studies in which the geometric structures and electronic properties of main group elements have influenced material structures and properties, and whereby their incorporation has enabled new strategies to synthesize such materials.

The removal of radioactive elements is important to human health and sustainable development. Here, the authors reveal the synthesis of water-stable Archimedean solids based on the earth-abundant element for the fast removal of trace iodine.

Bismuth organic frameworks can display interesting phosphorescent properties, but the relationship between structure and optical activity remains underexplored. Here two bismuth organic frameworks with differing bismuth coordination number and intermetallic distance are contrasted.

Polymer–polymer coupling reactions using an excess amount of chemical oxidants are wasteful. Here the authors report an electrochemical route for chain extension and topological transformations of poly(dimethylsiloxane).

Borates offer extended structural diversity and promise in diverse applications. Here the authors report a borate with linear BO₂ units as well as NMR spectroscopy characterization that provides a quantitative basis for identification of BO₂ units in polycrystalline and non-crystalline samples.