Ring-Conformations via the Competition of Electrostatic Interaction and Argentophilic Interaction. Cyclodimeric Structures of Silver Trifluoromethanesulfonate Containing Isonicotinate Ester Ligands

Abstract

Metallacyclodimers, [Ag(OTf)(L1)]2 and [Ag(L2)]2(OTf)2 (L1 = 1,3-dibromo-2,2-bis[(isonicotinoyloxy)methyl] propane; L2 = 2,5-dimethyl-2,5-bis(isonicotinoyloxy)hexane) were constructed and characterized. The crystal structure of [Ag(OTf)(L1)]2 reveals a 32-membered cyclodimer, whereas that of [Ag(L2)]2(OTf)2 shows a linked 34-membered cyclodimer chain via intercyclic argentophilic (Ag … Ag) interactions. [Ag(OTf)(L1)]2 affords “intramolecular π-π interaction cyclodimer” whereas [Ag(L2)]2(OTf)2 produces a racemic mixture of “twisted cyclodimer”. Ring-conformation of the cyclodimers was affected via the competition of electrostatic interaction and argentophilic interaction.