Fig. 5. (a) Chemical structure of MCDA 12. (b) Structure and SCSC polymerization of MCDA 13 yielding a tubular polymer. Water molecules are depicted as space-filling models. (c) Chemical structure of monomer 14 and (d) favourable packing of MCDA 14 in polymorph 14-I for TP. (e) SCSC polymerization of monomer 14 in polymorph 14-II resulting in the corresponding tubular polymer. (f) Chemical structures of MCDA 15 and terthiophene 16, and favourable packing of MCDA 15 in their cocrystal for the formation of a tubular polymer. (g) Crystal packing of the cocrystal 15·16 showing the presence of terthiophene 16 in the space between four supramolecular columns of MCDA 15. (h) Chemical structure of amide-based MCDA 17. The DA units are represented as a ball-and-stick model. H-atoms except N–H are omitted for clarity.