Mole-Ratio-Dependent Reversible Transformation between 2:2 and Cyclic 3:6 Silver(I) Complexes with an Argentivorous Molecule

A tetra-armed cyclen (L) with two substituted 3,5-difluorobenzyl and two substituted pyridine-4-yl methyl groups at the 1,4- and 7,10-positions of the cyclen ring as side arms was synthesized. When L was reacted with 1 equiv of the silver­(I), ­di­metallo­[3.3]­para­cyclophane-like 2:2 cyclic dimer, [Ag₂(L)₂]­(PF₆)₂, was obtained. The reaction of L with 2 equiv of silver­(I) gave a 3:6 cyclic trimer, [Ag₆(L)₃(CH₃CN)₃]­(OTf)₆·3CH₃CN. Furthermore, reversible complexation between the 2:2 cyclic dimer and 3:6 cyclic trimer was confirmed by ¹H NMR and the CSI mass in the addition of silver­(I) or the [2.2.2]­cryptand.