Nature of Alkali- and Coinage-Metal Bonds versus Hydrogen Bonds

We have quantum chemically studied the structure and nature of alkali- and coinage-metal bonds (M-bonds) versus that of hydrogen bonds between A-M and B- in archetypal [A-M center dot center dot center dot B](-) model systems (A, B=F, Cl and M=H, Li, Na, Cu, Ag, Au), using relativistic density functional theory at ZORA-BP86-D3/TZ2P. We find that coinage-metal bonds are stronger than alkali-metal bonds which are stronger than the corresponding hydrogen bonds. Our main purpose is to understand how and why the structure, stability and nature of such bonds are affected if the monovalent central atom H of hydrogen bonds is replaced by an isoelectronic alkali- or coinage-metal atom. To this end, we have analyzed the bonds between A-M and B- using the activation strain model, quantitative Kohn-Sham molecular orbital (MO) theory, energy decomposition analysis (EDA), and Voronoi deformation density (VDD) analysis of the charge distribution.

Automated summary

In this study, alkali- and coinage-metal bonds were quantum chemically studied and compared to hydrogen bonds. The research found that coinage-metal bonds are stronger than alkali-metal bonds, which are stronger than hydrogen bonds. Various analysis methods were used to understand how replacing the monovalent central atom of hydrogen bonds affects the structure, stability, and nature of the bonds.