Exploration into the host-guest supramolecular chemistry of p-sulfonatocalixarene with pyridine N-oxide and 4,4'-dipyridine N,N'-dioxide has resulted in the characterization of three new structural motifs with the calixarene in the ``up-down'' double partial cone conformation. Two are hydrogen-bonded network structures formed with pyridine N-oxide and either nickel or lanthanide metal counterions (1 and 2, respectively). Complex 1 displays host-guest interactions between pyridine N-oxide and the calixarene in the presence of hexaaquanickel(II) counterions. Complex 2 demonstrates selective coordination modes for different lanthanices involving the calixarene and pyridine N-oxide. The third structure, 3, is a coordination polymer which is formed with 4,4'-dipyridine N,N'-dioxide molecules which span a hydrophilic layer and join lanthanide/p-sulfonatocalixarene fragments. Although complexes 1-3 all have the calixarene in the ``up-down'' double partial cone conformation, 1 and 3 form bilayer arrangements within the extended structures while 2 forms a previously unseen corrugated bilayer arrangement.
Dalgarno, S. J., Hardie, M. J., Atwood, J. L., & Raston, C. L. (2004). Bilayers, corrugated bilayers, and coordination polymers of p-sulfonatocalixarene. Inorganic Chemistry, 43(20), 6351-6356. https://doi.org/10.1021/ic0493595