Boron as a key component for new π-electron materials*
Shigehiro Yamaguchi and Atsushi Wakamiya
Department of Chemistry, Graduate School of Science, Nagoya University, and SORST, Japan Science and Technology Agency, Chikusa, Nagoya 464-8602, Japan
Abstract: For the molecular design of new π-electron materials, the incorporation of main group elements into the π-conjugated frameworks is a powerful approach to modifying the nature of the parent π-conjugated systems. In particular, the group 13 boron is of interest, since the boron element has several characteristic features, such as an effective orbital interaction with the π-conjugated frameworks through the vacant p-orbital (i.e., pπ-π* conjugation), high Lewis acidity, and trigonal planar geometry. By exploiting these features of the boron atom, we have designed and synthesized several types of new π-electron materials, including trianthrylborane- or dibenzoborole-based π-conjugated systems as a new fluoride ion sensor, boryl-substituted thienylthiazole as a new building unit for electron-transporting materials, and B,B',B''-trianthrylborazine (B3N3)-based materials as a model of the bundled system of π-conjugated frameworks.
Keywords: boron; p-π* conjugation; fluoride ion sensors; electron-transporting materials; borazine.
*Paper based on a presentation at the 12th International Meeting on Boron Chemistry (IMEBORON-XII), Sendai, Japan, 11-15 September 2005. Other presentations are published in this issue, pp. 1299-1453.