Theoretical study on L–H+–L with identical donors: Short strong hydrogen bond or not?

Abstract

Short strong hydrogen bonds (SSHBs) play crucial role in many chemical processes. Recently, as the representative of SSHBs, [F-H-F]- was experimentally observed. [F-H-F]- has a symmetric structure, which can be described as a H+ acid shared by two terminal F- donors (F--H+-F-). To explore whether two identical donors are bound to result in SSHBs, we performed theoretical studies on a series of compounds (L-H+-L) with two identical electron donors (L corresponds to donors containing group 14, 15, 16 and 17 elements). The results show that identical donors do not definitely lead to SSHBs. Instead, typical hydrogen bonds also exist. We found that both electronegativity and basicity contribute to the patterns of hydrogen bonds, where more electronegative and weaker donors benefit to SSHBs. Besides, it was found that zero-point energies also respond to the hydrogen bonding systems. This systemic work is expected to provide more insights into SSHBs.

Staggered Assembly of a Dimeric Au13 Cluster: Impacts on Coupling of Geometric Isomerism

“…This different from Au 25 ‐ E , which was composed of a Σ D x 2 bonding MO. The LUMO was mainly localized in the central Ino decahedron (Figures 7h and 7i, Figure S18) [58–61] . After exciting Au 25 ‐ S to the S 1 state, the structural distortion caused by strong coherent vibrations leads to changes in the electronic coupling modes between the two Au 13 unit [6,26] .…”

“…By contrast, the LUMO of Au 25 ‐ E primarily consisted of the Σ D x 2 bonding MO (Figure S18). D xz refers to the extension direction of the superatomic D orbital along the diagonal of the x and z axes, whereas D x 2 refers to the extension direction along the x axis [58–61] . Hirshfeld percentages of the orbital compositions of the frontier MOs of Au 25 ‐ S and Au 25 ‐ E are summarized in Tables S1 and S2.…”