One-dimensional hydrogen bonded polymers based on C-methyl-calix[4]resorcinarene and a crystal engineering design strategy

The X-ray crystal structures of co-crystals involving C-methylcalix[4]resorcinarene 1 and exo-bidentate pyridines 2 are reported. The components assemble such that the calixarenes adopt a C-2v conformation and the pyridines serve as bifunctional hydrogen bond accepters. In the case of linear bridging units, 4,4'-bipyridine 2a and 4,4'-dipyridyl butanedioate 2b, the assembly process yields 1D wave-like hydrogen bonded polymers 4a and 4b, respectively, which include guest solvent molecules within 1. In the case of an angular bridging unit, pyrimidine 2c, the assembly process yields a 1D chain 5 which exhibits self-inclusion. Thermal analysis of 4a demonstrates that the thermal behavior of these compounds is independent of the nature of the included guest, the solvent-included lattices being stable up to 190 degrees C. (C) 1998 Elsevier Science Ltd.