Lj. Barbour et Jl. Atwood, Non-covalent interactions exert extraordinary influence over conformation and properties of a well-known supramolecular building block, CHEM COMMUN, (19), 2001, pp. 2020-2021
At low pH, and in the presence of 4,4'-bipyridine, p-sulfonatocalix[4]arene
crystallizes in the 1,3-alternate conformation rather than the expected co
ne conformation and exhibits remarkable stability.