Host–guest interactions have been exploited to create new linear and cyclic AABB supramolecular polymers composed of tetraphosphonate cavitands and N-methylpyridinium salts.

Enrico Dalcanale and co-workers, Parma, Italy, have designed the new polymers by controlling the flexibility of the ditopic guest spacer, the solvent, and the concentrations used in the system. Solid-state studies have shown that linear polymerization is preferred.

• Host–Guest-Driven Copolymerization of Tetraphosphonate Cavitands,
  Francesca Tancini, Roger M. Yebeutchou, Laura Pirondini, Rita De Zorzi, Silvano Geremia, Oren A. Scherman, Enrico Dalcanale,
  Chem Eur. J. 2010, 16 (48).
  DOI: 10.1002/chem.201002237