title: Optical properties of disilane-bridged donor-acceptor architectures: strong effect of substituents on fluorescence and nonlinear optical properties.
abstract: A series of disilane-bridged donor-acceptor architectures 1-9 containing strong electron-donating and -withdrawing substituents were designed and synthesized in acceptable yields. The substituents substantially affected the fluorescence and nonlinear optical properties of the compounds. In the solid state, the compounds showed purple-blue fluorescence (λ(em) = 360-420 nm) with high quantum yields (up to 0.81). Compound 3, which had p-N,N-dimethylamino and o-cyano substituents, exhibited optical second harmonic generation (activity 2.9 times that of urea, calculated molecular hyperpolarizability β = 1.6 × 10(-30) esu) in the powder state. Density functional theory calculations for the ground and excited states indicated that both the locally excited state and the intramolecular charge transfer excited state make important contributions to the luminescence behavior.
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Shimada
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Yamanoi
authors.forename: Tomonori
authors.initials: T
authors.lastname: Matsushita
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
authors.forename: Eiji
authors.initials: E
authors.lastname: Nishibori
authors.forename: Akari
authors.initials: A
authors.lastname: Hatakeyama
authors.forename: Kunihisa
authors.initials: K
authors.lastname: Sugimoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishihara