Theoretical Prediction of a Neutral Zero‐Valent Beryllium Compound Isoelectronic with Singlet Carbenes

Abstract

Electronic structure and reactivity of a neutral Be(0) compound stabilized by N‐donor ligand L [L, bis(imidazolin‐2‐imine)], has been studied using density functional theory. The studied compound is found to have sufficient Be‐L bond dissociation energy. The electronic structure study reveals that this compound is isoelectronic with singlet carbenes. Topological analysis reveals the Be‐L bond to be of donor‐acceptor type. The presence of a rare Be…Hγ agostic interaction is also observed in the compound. The gas phase proton affinity of the compound is found to be very high (> 300 kcal/mol) and should be considered as “super basic”. The proton affinity of this compound (330‐334 kcal/mol) is found to be even higher than those of singlet carbenes. The promising ligating property with Lewis acid BH3 and BeCl2 has been noted. Its complex with BeCl2 is found to have very high bond dissociation energy with a strong Be−Be bond. Our computational results reveal that the proposed compound has the highest Lewis basicity among Be(0) compounds found in literature.

Five-membered N-heterocyclic beryllium(i) compounds: fluctuating electronic structures with ambiphilic reactivity

“…The C–C and C–N bonds are elongated and the Be–N bonds are shortened as compared to compound VIII , prepared and characterized by Paparo and Jones, 30 and Be(0) compounds, proposed by Guha and coworkers. 31…”

“…This is because several unconventional beryllium compounds have been reported experimentally and theoretically. 1–31 Apart from classical ionic and covalent compounds, di-, tri-, tetra-, penta-, and hexa-coordinated beryllium compounds and compounds with Be–Be multiple bonds have been explored. 1–26 The high ionization potential, low reduction potential, and 75% vacant valence orbital are the major reasons for the divergent chemistry of beryllium.…”

“…4 Several compounds have been reported in which beryllium is a part of the ring system. 1,6,10,25,26,[29][30][31] An electronic structural study on the neutral Be(0) compound stabilized by the bis(imidazolin-2-imine) ligand reveals that this compound is isoelectronic to singlet carbene. 31 The localized lone pair orbital on beryllium makes this compound "super basic", which is evident from the high proton affinity values and ligating property with Lewis acids.…”

Ein neutrales Beryllium(I)‐Radikal

“…[5] Obwohl die Realisierbarkeit von Be I -Be I -gebundenen Spezies vorhergesagt wurde [6] und das Be 2 -Dimer spektroskopisch beobachtet wurde, [7] macht die niedrige Be-Be-Bindungsenthalpie einkernige Be 0 -Verbindungen zu zugänglicheren Zielen. [8] Im Jahr 2016 berichtete unsere Gruppe über die erste Be 0 -Verbindung, den Komplex III, der seine Stabilität einer starken Drei-Zentren-zwei-Elektronen-p-Rückbindung vom Be 0 -Atom in seiner 2s 0 2p 2 -Elektronenkonfiguration zu den neutralen cyclischen Alkyl(amino)carben (CAAC)-Liganden verdankt. [9] Dieser wurde seitdem als Reduktionsmittel zur Synthese des ersten Carben-Bismutiniden-Komplexes verwendet.…”

“…Die Organoberylliumhalogenid-Vorstufen (CAAC)- [8] in Toluol bei À78 8C hergestellt und als hellorange Feststoffe in ausgezeichneten Ausbeuten (! 82 %, Schema 1 a) isoliert.…”