“Cyclic Tetramer” vs “Dimer of Cyclic Dimer”: Subtle Anion Effects on the Cyclization of AgBF4 vs AgClO4 with Bis(3-pyridyl)dimethylsilane

Subtle anion effects have been observed for the cyclization of AgX (X - = BF 4 - vs ClO 4 - ) with bis(3-pyridyl)dimethylsilane. For the two similar anions, BF 4 - affords a “cyclic tetramer” with two independent spaces, while ClO 4 - affords a “dimer of cyclic dimer” via an unusual intercyclic argentophilic interaction. For BF 4 -, the specific X - ···H−C interactions seem to play an important role in the formation of the cyclic tetramer.