Synthesis and solid-state polymerization of diacetylene derivatives directly substituted with a phenylcarbazole moiety

Five asymmetric diacetylene carbamates that possessed a 9-phenyl-9H-carbazol-3-yl (PhCz) group as an aromatic donor that was directly attached to the diacetylene moiety were designed and synthesized. Upon UV irradiation, the highest conversion to the corresponding polydiacetylene was obtained for the benzyl carbamate derivative, and its regular 1,4-addition was confirmed by formation of a greenish-blue polymer that exhibited characteristic excitonic absorption bands. In addition, a small ionization potential of 5.2 eV was observed for this polydiacetylene.