!!Synthesis of ¦Ð-Conjugated Materiarls Based on Carboranes

Carborane(C2B10H12) is a polyhedral carbon and boron cluster compound, which has unique properties such as neutron capturing ability based on boron atom, strong electron-withdrawing capacity, and thermal as well as chemical stability.  We have recently focused on the development of ¦Ð-conjugated compounds and polymers that contain 1,2-disubstituted ''o''-carborane units.

¦Ð-Conjugated molecules and polymers with the 1,2-disubstituted ''o''-carborane units show aggregation-induced emission (AIE) properties.  In solution, intramolecular charge transfer (ICT) from the ¦Ð-conjugated moieties to the C1-C2 bond of ''o''-carborane quenches the emission; in contrast, in the aggregation state, freezing of the molecular motion suppresses the vibrational radiation and allows the emission. The ''o''-carborane dyes are expected to be applied to light-emitting devices.

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Benzocarborane is one of derivatives of ''o''-carborane, in which a benzene ring and the carbon-carbon bond of ''o''-carborane are fused to form a benzenoid ring structure on the carborane cage.  We reported the ¦Ð-conjugated polymer having benzocarborane units and aromatic rings-fused benzocarborane.  Because of the highly planar ¦Ð-conjugated moiety, benzocarborane is a good candidate for the optical and electronic materials utilizing carborane properties.

{{ref_image HP_carbo_fig2_ENG.png}}