Synthesis and Optical, Electrochemical, and Electron-Transporting Properties of Silicon-Bridged Bithiophenes

• Published in: Organometallics Vol. 18; no. 8; pp. 1453 - 1459
• Main Authors: Ohshita, Joji, Nodono, Mitsunori, Kai, Hiroyuki, Watanabe, Tsuguo, Kunai, Atsutaka, Komaguchi, Kenji, Shiotani, Masaru, Adachi, Akira, Okita, Koichi, Harima, Yutaka, Yamashita, Kazuo, Ishikawa, Mitsuo
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 12.04.1999; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Physical Sciences; Science & Technology; SERIES; POLYMERIC ORGANOSILICON SYSTEMS; POLYSILANES; COOLIGOMERS; COPOLYMERS; PI-CONJUGATED POLYMERS; UNITS
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om980918n

A series of bithiophene derivatives bearing an intramolecular monosilanylene or disilanylene bridge between the β,β‘-positions were synthesized, and their properties were investigated. UV spectral and cyclic voltammetric analyses of the silicon-bridged bithiophenes indicated that they have lower lying LUMOs, relative to those for bithiophene and methylene bridged bithiophenes, probably due to σ*−π* interaction between the silicon atom(s) and bithiophene π-orbitals, in good agreement with the results of theoretical calculations using simplified model compounds based on RHF/6-31G. The silicon-bridged bithiophenes exhibit high electron-transporting properties, and triple-layer-type electroluminescent (EL) devices, using the silicon-bridged bithiophenes, tris(8-quinolinolato)aluminum(III) complex (Alq), and N,N‘-diphenyl-N,N‘-di-m-tolylbiphenyl-4,4‘-diamine (TPD) as the electron-transporting, emitting, and hole-transporting layers, respectively, emitted strong EL.