Novel conjugated donor-π-acceptor molecules based on 1,3-diselenol-2-ylidene units

✍ Scribed by Antony Chesney; Martin R. Bryce; Andrew Green; Alexander K. Lay; Shimon Yoshida; Andrei S. Batsanov; Judith A.K. Howard; Jean-Marc Fabre; Azarang Javidan; Laurent Binet

• Publisher: Elsevier Science
• Year: 1998
• Tongue: French
• Weight: 640 KB
• Volume: 54
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(98)00812-6

✦ Synopsis

Abstro~t: The synthesis is described of a series of conjugated donor-~-acceptor molecules where 1,3-diselenoles are the electron donor moieties and dicyanomethylene or N-cyanoimine groups function as the acceptor moieties. Alkenes and aryl groups act as the conjugated spacers. The UV-VIS absorption spectra of these molecules in solution possess a low energy band resulting from intramolecular charge transfer; the wavelength of this band varies significantly with the structure of the spacer group. The solution redox properties, studied by cyclic voltammetry, reveal a reversible one-electron oxidation wave, attributed to the formation of the radical cation of the 1,3-diselenol-2-ylidene moiety, and an irreversible one-electron reduction to form the radical anion located on the dicyanomethylene or N-eyanoimine groups. The X-ray crystal structure of 9-(1,1-dicyanomethylene)-10-(4,5dimethyl-l,3-diselenol-2-ylidene)-9,10-dihydroanthraeene 14 is reported. The molecule is strained and adopts a "butterfly conformation" in the ground state due to unfavourable peri-interactions between the 1,3-diselenole selenium atoms and the peri hydrogens.