title: Synthesis of Quinoidal Fused Oligosiloles by Rhodium-Catalyzed Stitching Reaction and Theoretical Investigation of Their Properties.
abstract: New quinoidal fused oligosiloles containing an even number of silole units have been synthesized by a rhodium-catalyzed stitching reaction. Employing [RhCl(tfb)]2as the catalyst significantly improved the stitching efficiency, and up to six siloles could be fused in quinoidal form. A systematic comparison of the physical properties of Si1-Si6' confirmed the unique trend in their LUMO levels, which become higher with longer π conjugation. To understand the origin of this unusual trend, theoretical calculations were also carried out using various model compounds, and the results indicated that the terminal indenylidene (cyclopentadienylidene) moieties in Si1-Si6 (Si1a-Si6a) are primarily responsible for this phenomenon through their frontier orbital correlations with the HOMO of the central polyene unit, which becomes higher in energy with longer π conjugation.
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Ryo
authors.identifier: 0000-0002-3324-9393
authors.initials: R
authors.lastname: Shintani
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Nana
authors.initials: N
authors.lastname: Misawa
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Tsuda
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Iino
authors.affiliation: Department of Chemical System Engineering, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Mikiya
authors.initials: M
authors.lastname: Fujii
authors.affiliation: Department of Chemical System Engineering, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yamashita
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Kyoko
authors.identifier: 0000-0002-0321-5299
authors.initials: K
authors.lastname: Nozaki