Synthesis and Solid-State Polymerization of Diacetylene Derivatives with an N-Carbazolylphenyl Group

Abstract

Four diacetylene derivatives with an N-carbazolylphenyl group as a donor moiety have been synthesized and subsequently characterized. These diacetylene derivatives undergo solid-state polymerization via UV irradiation, although these compounds have relatively large π-conjugated aromatic groups. The polymerization behaviors of these derivatives were confirmed by distinct absorption bands for polydiacetylenes. The reactive process is strongly influenced by the slightly differing side groups. Single crystal growth of the two compounds was successful and their crystal structure analyses revealed large differences in the molecular conformations and intermolecular geometries caused by a methylene unit. The HOMO population of the monomers is predominantly expressed in the phenyl carbazole unit, while each polymer showed differing HOMO energies with some polymers exhibiting high-lying HOMO levels.

Synthesis, Crystal Structures, and Solid-State Polymerization of 8-[4-(Dimethylamino)phenyl]octa-5,7-diynyl Carbamates

“…In our previous studies, we obtained the ionization potentials of CP-and PC-type monomers (Figure 2) to be about 6.0 and 5.8 eV, respectively. 45,46 In comparison with these values, DMAP-type monomers have smaller ionization potentials, which agreed with the results on the HOMO energy calculation mentioned in the Introduction. The ionization potentials of the photopolymerized samples could be obtained for 5c and 5f, and they were 5.92 and 6.12 eV, respectively.…”

“…38,39 For example, polymerizable butadiyne monomers have been obtained by introducing urethane group forming intermolecular hydrogen bonding in both substituents 40,41 or even in one of two substituents. 42−44 In our previous studies, we synthesized butadiyne derivatives substituted by 4-(carbazol-9-yl)phenyl (CP) or (9-phenyl)carbazol-3-yl (PC) group to obtain PDAs with small ionization potentials, 45,46 which were potential materials for holeinjection electrodes. Since hole injection and transport properties of the PDAs seems to be strongly affected by the highest occupied molecular orbital (HOMO) levels of the corresponding monomers, monomers with a smaller ionization potential are worth investigating.…”

Synthesis and Solid-State Polymerization of 5-(Pyren-1-yl)penta-2,4-diyn-1-ol Derivatives with an N-Phenylurethane or N-Benzylurethane Group

“…One of the strategies is to use a supramolecular host–guest system. , The other is modification by specific groups, which tend to align monomers in one-dimensional (1D) arrays. We have used the latter strategy to prepare butadiyne monomers with π conjugation between the backbone and substituents. , For example, butadiyne derivatives directly bound to electron-donating aromatics such as pyrene, , N -phenylcarbazole, , aniline, , and tetrathiafluvalene (TTF) were recently synthesized, and some of them polymerized regularly to form PDAs with conjugated donors. Meanwhile, in order to improve the PDA processability, one of the potential approaches is its solubilization.…”