Tetra‐armed cyclen (1) bearing two 4‐(4′‐pyridyl)benzyl and two 3,5‐difluorobenzyl groups and its Ag+ complexes were prepared and structurally characterized. The complexes formed between 1 and Ag+ undergoes a reversible structural transformation between a 2:2 dimeric complex and a 3:5 pentacyclic trefoil complex with changes in the Ag+/1 molar ratio. It was also revealed that the 3:5 trefoil complex could encapsulate benzene and [D6]benzene selectively in solid‐state. The benzene‐included structures are stabilized by C−H⋅⋅⋅F−C interactions between the benzene molecule and the ligand molecule.

The synthesis of a tetra-armed cyclen (L) with two benzyl groups at the 1- and 7-positions and two pyridin-4-ylmethyl groups at the 4- and 10-positions as side arms and the solvent- and/or molar-ratio-dependent coordination modes in the formation of silver­(I) complexes are reported. 1H NMR and cold-spray-ionization mass spectrometry studies suggest that a silver­(I) complex with L gives different species depending on the molar ratio of silver ions used as the reactant. Furthermore, the conformation of cyclen in the one-dimensional (1D) coordination polymers, obtained using 2 equiv of silver­(I), changes depending on the presence or absence of acetonitrile. When L was reacted with 1 and 2 equiv of silver­(I) triflate in a mixed solvent system (CH2Cl2/CH3OH/CH3CN), a dimetallo[3.3]­paracyclophane-like discrete cyclic dimer, [Ag2 L 2]­(OTf)2 (1), and a 1D coordination polymer, [Ag2 L(OTf)2(CH3CN)] n (2), respectively, were obtained as single crystals. In the absence of acetonitrile, a zigzag 1D coordination polymer, {[Ag2 L(OTf)]­OTf·3CH2Cl2} n (3), was obtained when 2 equiv of silver­(I) was used. Molar-ratio-dependent structural changes were not observed when L was reacted with AgBF4 or AgPF6 in the CH2Cl2/CH3OH/CH3CN mixed-solvent system. The solvent effect on the coordination modes can be explained by the coordination ability of the solvents toward the metal cation affecting the conformation of the cyclen.

Tetra‐armed cyclen (1) bearing two 4‐(4′‐pyridyl)benzyl and two 3,5‐difluorobenzyl groups and its Ag+ complexes were prepared and structurally characterized. The complexes formed between 1 and Ag+ undergoes a reversible structural transformation between a 2:2 dimeric complex and a 3:5 pentacyclic trefoil complex with changes in the Ag+/1 molar ratio. It was also revealed that the 3:5 trefoil complex could encapsulate benzene and [D6]benzene selectively in solid‐state. The benzene‐included structures are stabilized by C−H⋅⋅⋅F−C interactions between the benzene molecule and the ligand molecule.