Soluble poly(diacetylene)s using the perfluorophenyl-phenyl motif as a supramolecular synthon

A series of diacetylene monomers with benzoyl, 4-hexylbenzoyl, 4-dodecylbenzoyl, and perfluorobenzoyl substituents were synthesized and investigated with respect to their crystal structures and polymerizability. In the absence of perfluorophenyl-phenyl interactions, the crystal structures of related alkylated and nonalkylated derivatives were substantially different and dominated by the phase segregation between the alkylated side chains and the diaryl-substituted diacetylene cores. By contrast, the perfluorophenyl-phenyl interactions served as a reliable supramolecular synthon in that they persisted in the crystal structures of different alkylated and nonalkylated derivatives. The packing of the diacetylene functions was appropriate for a topochemical polymerization in these cases, and the perfluorophenyl-phenyl interaction determined the polymerization direction. As a result, soluble alternating diacetylene copolymers were obtained which were further characterized with solution phase methods.