Hydrogen-Bonding Acceptor Character of Be₃, the Beryllium Three-Membered Ring

Abstract

The ability of Be as a hydrogen bond acceptor has been explored by studying the potential complexes between this molecule and a set of hydrogen bond donors (HF, HCl, HNC, HCN, HO, and HCCH). The electronic structure calculations for these complexes were carried out at the MP2 and CCSD(T) computational levels together with an extensive NBO, ELF, AIM, and electrostatic potential characterization of the isolated Be system. In all the complexes, the Be-Be σ bond acts as electron donor, with binding energies between 19 and 6 kJ mol. A comparison with the analogous cyclopropane:HX complexes shows similar binding energies and contributions of the DFT-SAPT energetic terms. A blue-shift of the harmonic frequencies of Be is observed upon complexation.

A−H…σ Hydrogen Bonds: Dihydrogen and Cycloalkanes as Proton Acceptors

“…It is worth to mention that the binding energies for simple cyclopropane complexes calculated at the MP2/aug’‐cc‐pVTZ level were presented recently to compare them with the analogues complexes of the cyclic Be 3 moiety . Few cyclopropane complexes analyzed here were presented also in the above‐mentioned study .…”

“…It was found that the A−H…σ interactions are not meaningless here, however the absolute value of the binding energy (−E bin ) does not exceed 5 kcal mol −1 , the strongest interaction was detected for the Be 3 …HF complex . In the latter study the binding energies of the Be 3 complexes are compared with the corresponding complexes with the C 3 H 6 species playing a role of the Lewis base . The cyclopropane complexes are characterized by slightly stronger interactions than their Be 3 counterparts …”

“…The strongest A−H…σ interaction was observed for the B 2 H 4 …HF complex where the binding energy corrected for BSSE amounts ∼−6.5 kcal mol −1 . In another study an analysis of the complexes of the cyclic Be 3 with species acting as the Lewis acid was performed on the basis of the MP2 and CCSD(T) calculations (aug’‐cc‐pVTZ basis set was applied) . The single Be−Be σ‐bond plays in the latter complexes a role of the Lewis base.…”

“…In the latter study the binding energies of the Be 3 complexes are compared with the corresponding complexes with the C 3 H 6 species playing a role of the Lewis base . The cyclopropane complexes are characterized by slightly stronger interactions than their Be 3 counterparts …”

Efficient Evaluation of Molecular Electrostatic Potential in Large Systems

“…However, albeit this analysis of MESP topology is breaking through in current research, its application to large systems is being hindered by the cost of computing accurate values of MESP and its derivatives. Thus, the introduction of more efficient procedures like that proposed herein has greatly facilitated this type of studies, and several works using the new algorithms have appeared in recent literature [22][23][24][25].…”