A nucleophilic beryllyl complex via metathesis at [Be–Be] 2+

Owing to its high toxicity, the chemistry of element number four, beryllium, is poorly understood. However, as the lightest elements provide the basis for fundamental models of chemical bonding, there is a need for greater insight into the properties of beryllium. In this context, the chemistry of the homo-elemental Be–Be bond is of fundamental interest. Here the ligand metathesis chemistry of diberyllocene (1; CpBeBeCp)—a stable complex with a Be–Be bond—has been investigated. These studies yield two complexes with Be–Be bonds: Cp*BeBeCp (2) and [K{(HCDippN)2BO}2]BeBeCp (3; Dipp = 2,6-diisopropylphenyl). Quantum chemical calculations indicate that the Be–Be bond in 3 is polarized to such an extent that the complex could be formulated as a mixed-oxidation state Be0/BeII complex. Correspondingly, it is demonstrated that 3 can transfer the ‘beryllyl’ anion, [BeCp]−, to an organic substrate, by analogy with the reactivity of sp2–sp3 diboranes. Indeed, this work reveals striking similarities between the homo-elemental bonding linkages of beryllium and boron, despite the respective metallic and non-metallic natures of these elements

Diberyllocene, a stable compound of Be(I) with a Be-Be bond

The complex diberyllocene, CpBeBeCp (Cp, cyclopentadienyl anion), has been the subject of numerous chemical investigations over the past five decades yet has eluded experimental characterization. We report the preparation and isolation of the compound by the reduction of beryllocene (BeCp2) with a dimeric magnesium(I) complex and determination of its structure in the solid state by means of x-ray crystallography. Diberyllocene acts as a reductant in reactions that form beryllium-aluminum and beryllium-zinc bonds. Quantum chemical calculations indicate parallels between the electronic structure of diberyllocene and the simple homodiatomic species diberyllium (Be2)

A Crystalline Tri-thorium Cluster with σ-Aromatic Metal-Metal Bonding.

From PubMed via Jisc Publications RouterHistory: received 2020-12-07, accepted 2021-08-06Publication status: aheadofprintMetal-metal bonding is a widely studied area of chemistry , and has become a mature field spanning numerous d transition metal and main group complexes . In contrast, actinide-actinide bonding is predicted to be weak , being currently restricted to spectroscopically-detected gas-phase U and Th , U H and U H in frozen matrices at 6-7 Kelvin (K) , or fullerene-encapsulated U . Conversely, attempts to prepare thorium-thorium bonds in frozen matrices produced only ThH (n = 1-4) . Thus, there are no isolable actinide-actinide bonds under normal conditions. Computational investigations have explored the likely nature of actinide-actinide bonding , concentrating on localised σ-, π-, and δ-bonding models paralleling d transition metal analogues, but predictions in relativistic regimes are challenging and have remained experimentally unverified. Here, we report thorium-thorium bonding in a crystalline cluster, prepared and isolated under normal experimental conditions. The cluster exhibits a diamagnetic, closed-shell singlet ground-state with a valence-delocalised three-centre-two-electron σ-aromatic bond that is counter to the focus of previous theoretical predictions. The experimental discovery of actinide σ-aromatic bonding adds to main group and d transition metal analogues, extending delocalised σ-aromatic bonding to the heaviest elements in the periodic table and to principal quantum number six, and constitutes a new approach to elaborating actinide-actinide bonding. [Abstract copyright: © 2021. The Author(s), under exclusive licence to Springer Nature Limited.