A Very Short Be–Be Distance but No Bond: Synthesis and Bonding Analysis of Ng–Be₂O₂–Ng′ (Ng, Ng′=Ne, Ar, Kr, Xe)

Abstract

Short interatomic distances below standard values for a single bond are usually identified with double or triple bonds. The synthesis and spectroscopic characterization of a molecule is reported where the distance between two beryllium atoms is shorter than a standard double bond but there is no bond. The cyclic diberyllium dioxide Be O molecule, which is coordinated by two noble gas atoms in Ng-Be O -Ng' (Ng, Ng'=Ne, Ar, Kr, Xe) was isolated and spectroscopically identified in low-temperature matrices. The complexes possess very short Be-Be distances, but the analysis of the electronic structure reveals that there is no chemical bond.

Formation and Characterization of a BeOBeC Multiple Radical Featuring a Quartet Carbyne Moiety

“…The reaction of Be 2 and CO as well as the conversion of the identified species of BeBeCO to BeCOBe and BeOBeC are reminiscent of the previously discovered activation procedure of N 2 on diatomic Gd 2 molecules, where N 2 reacts with Gd 2 to form Gd 2 (μ‐η 2 :η 1 ‐N 2 ), and Gd(μ‐N) 2 Gd in sequence . Similar procedure occurs for Be 2 and O 2 , as is shown before . Therefore the interaction mechanism of N 2 , O 2 , and CO on diatomic species provides insight for understanding the activation of small molecules on metal clusters and nanoparticles.…”

Nature of the chemical bonding inD3h[MH3M]+cations (M = Be, Mg)

“…Our BeBe distances turn out to be very slightly smaller (by about 0.01 Å) than the already small values found by Zhao et al We notice that the BeBe separations in the D 3 h [NgBeH 3 BeNg] + cations are ca. 0.04 Å shorter than those found for the rhombic Be 2 O 2 cluster . We are not aware of any previously reported geometries for the magnesium systems.…”

“…Calculations and analysis carried out by Rohman et al also support the notion of Be≡Be triple bonds in various systems, including Be 2 X 6 (X = Li, Na), but they found the BeBe bonding to be ultraweak in spite of the very short BeBe distances . Indeed, some systems have been studied both experimentally and computationally, such as the rhombic Be 2 O 2 cluster, which feature very short BeBe distances in the absence of any direct BeBe chemical bonding …”

“…In spite of the obvious deterrence for experimentalists of the high toxicity of beryllium compounds, a great deal is now known about the organometallic and coordination chemistry of beryllium . Beryllium compounds that have been studied experimentally and especially computationally include various systems that feature BeBe bonding and/or very short BeBe distances . For example, it has been shown for various choices of X, such as a fluorine atom or an appropriate N‐heterocyclic carbene ligand, that certain XBeBeX species feature Be−Be bonds that are both significantly stronger and shorter than the weak and rather long bond in Be 2 .…”

Metall‐Metall‐Mehrfachbindung oder keine Bindung? Die elektronische Struktur von V2O2

“…Ergebnis und würde füre in V 2 O 2 ohne V-V-Bindung sprechen. Das V 2 O 2 -Moleküli st also ein weiteres Beispiel einer anscheinend einfachen rhombischen M 2 (m-X)2 -Struktur,f ür die die Klärung der elektronischen Struktur eine sorgfältige Untersuchung erfordert [35]. Wegen der widersprüchlichen theoretischen Ergebnisse ist offensichtlich, dass Dichtefunktionalrechnungen fürzuverlässige Voraussagen nicht geeignet sind.…”