In the presence of 1,2-bis(4,4'-dipyridinium)ethane, p-sulfonatocalix[5]arene (C5AS) adopts an unseen partial-cone conformation to form back-to-back dimers, whereas C5AS crystallizes in face-to-face dimers to form a wavy layer, rather than the expected bilayer, arrangement upon complexation with 1,2-bis(pyridinium)ethane.