Coordination-Driven Self-Assembly of a Discrete Molecular Cage and an Infinite Chain of Coordination Cages Based on <i>ortho</i>-Linked Oxacalix[2]benzene[2]pyrazine and Oxacalix[2]arene[2]pyrazine

Coordination-driven self-assembly of ortho-linked oxacalix[2]benzene[2]pyrazine (1) as well as oxacalix[2]arene[2]pyrazine (2) with a silver cation resulted in the formation of a discrete molecular cage (3) and a one-dimensional chain of coordination cages (4), respectively. Single crystal X-ray diffraction analysis confirmed the structures of 3 and 4. The silver ions in 3 adopted tetrahedral coordination geometries while the silver ions in 4 adopted square-planar coordination geometries. The void of the metal-containing cage 3 was occupied by a methyl group of an acetonitrile bonded to a neighboring cage in the solid state, and one benzene ring was found to reside in the void of each cage of complex 4.