Argentophilicity as essential driving force for a dynamic cation-cation host-guest system: [Ag(acetonitrile)₂]⁺⊂[Ag₂(bis-NHC)₂]²⁺ (NHC = N-heterocyclic carbene)

Inorg Chem. 2014 Oct 6;53(19):10654-9. doi: 10.1021/ic501715h. Epub 2014 Sep 16.

Abstract

A cationic [Ag2(bis-NHC)2](2+) system behaves as an excellent host for Ag(+). In the solid-state variation, Ag···Ag are the only bonding interactions between host and guest, overcoming their inherent electrostatic repulsion. It represents a clear example of ligand-unsupported ("pure") argentophilicity. In solution, we also found evidence for this kind of Ag···Ag approximation, which might be recognized as an initial step of transmetalation mechanisms involving formally closed-shell metal centers as transferring agents.