Anion Anion Coinage Bonds: The Case of Tetrachloridoaurate

Interactions in crystalline tetrachloridoaurates of acetylcholine and dimethylpropiothetine are characterized by Au Cl and Au O short contacts. The former interactions assemble the AuCl4- units into supramolecular anionic polymers, while the latter interactions append the acetylcholine and propiothetine units to the polymer. The distorted octahedral geometry of the bonding pattern around the gold center is rationalized on the basis of the anisotropic distribution of the electron density, which enables gold to behave as an electrophile (pi-hole coinage-bond donor). Computational studies prove that gold atoms in negatively charged species can function as acceptors of electron density. The attractive nature of the Au Cl/O interactions described here complement the known aurophilic bonds involved in gold-centered interactions.

Automated summary

Interactions in crystalline tetrachloridoaurates of acetylcholine and dimethylpropiothetine are characterized by short contacts of Au Cl and Au O. The attractive nature of the Au Cl/O interactions complements the known aurophilic bonds involved in gold-centered interactions. Computational studies show that gold atoms in negatively charged species can function as electron density acceptors.