Ladder π-conjugated materials with main group elements*
Shigehiro Yamaguchi, Caihong Xu, and Toshihiro Okamoto
Department of Chemistry, Graduate School of Science, Nagoya University, and SORST, Japan Science and Technology Agency, Chikusa, Nagoya 464-8602, Japan
Abstract: Ladder-type π-conjugated skeletons are promising building units for new materials for organic electronics, wherein their annelated coplanar structures enhance the π-conjugation, leading to a set of desirable properties such as intense fluorescence and high carrier mobility. As a new entry into this class of skeletons, we now disclose two series of ladder molecules, i.e., silicon- and carbon-bridged oligo(p-phenylenevinylene)s and thiophene- and selenophene-based heteroacenes. The former ladder molecules contain the silole substructure in which the silicon bridges affect the electronic structure and thus photophysical properties through the σ*-π* conjugation. The latter heteroacenes can be recognized as the heteroatom analogs of acenes and may be promising materials for organic thin film transistors. These two series of molecules have been synthesized based on newly developed intramolecular cyclizations of acetylenic compounds.
Keywords: ladder oligo(p-phenylenevinylene)s; silicon; heteroacenes; intramolecular cyclization; fluorescence.
*Paper based on a presentation at the 11th International Symposium on Novel Aromatic Compounds (ISNA-11), St. John's, Newfoundland, Canada, 14-18 August 2005. Other presentations are published in this issue, pp. 685-888..