title: Hybrid [5]Radialenes with Bispyrroloheteroles: New Electron-Donating Units.
abstract: Bispyrroloheteroles have been synthesized to address their intrinsic structural, optical, and electrochemical properties. The X-ray crystal structures and calculated natural bond orbital (NBO) bond orders unambiguously demonstrated the existence of a two pyrrole-fused five-membered ring with short exocyclic C-C double bonds and long endocyclic C-C single bonds, supporting that the bispyrroloheteroles are rare examples of structurally characterized hybrid [5]radialenes. The bispyrroloheteroles were found to act as an electron-donating unit, which would be fascinating for the rational design of new charge-transporting and donor-acceptor photovoltaic materials as well as versatile charge-transfer complexes.
authors.affiliation: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510 (Japan).
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Higashino
authors.affiliation: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510 (Japan). imahori@scl.kyoto-u.ac.jp.|Institute for Cell-Material Sciences (WPI-iCeMS), Kyoto University, Nishikyo-ku, Kyoto, 615-8510 (Japan). imahori@scl.kyoto-u.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imahori
keywords: UV/Vis spectroscopy; X-ray diffraction; charge transfer; donor-acceptor systems; heterocycles