The reaction of AgX (X -= NO 3 -, ClO 4 -, or CF 3 SO 3 -) with 1,3-bis(3-pyridyl)tetramethyldisiloxane (L) at room temperature affords 20-membered metallacyclodimers, [Ag(L)] 2 (X) 2 . For the macrocyclodimer, fine competition among argentophilic, electrostatic, and pÁÁÁp interaction exists. The macrocyclodimer is a unique molecular chair that tunes a transannular argentophilic interaction via the bite size of the counteranions. In order to reversibly control the argentophilic interaction, anion exchange has been accomplished. The anion exchangeability depends on the water solubility rather than the electrostatic interaction between silver(I) and anions.