Synthesis and Physical Properties of Tetrathiafulvalene-8-Quinolinato Zinc(II) and Nickel(II) Complexes

• Main Authors: Keijiro Tsujimoto, Shinya Yamamoto, Hideki Fujiwara
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Inorganics
• Subjects: tetrathiafulvalene; photofunctional materials; optical properties; photoelectric conversion
• Online Access: https://www.mdpi.com/2304-6740/9/2/11

To develop donor–acceptor–donor (D–A–D) type new photo-electric conversion materials, new tetrathiafulvalene (TTF)-Mq₂-TTF complexes <b>1</b> and <b>2</b> were synthesized, where two bis(<i>n</i>-hexylthio)tetrathiafulvalene moieties were attached to the Mq₂ part (<b>1</b>: M = Zn, <b>2</b>: M = Ni, q = 8-quinolinato) through amide bonds. UV-Vis absorption spectra of these complexes showed strong and sharp absorption maxima at 268 nm and small absorption maxima around 410 nm, corresponding to those of Znq₂ and Niq₂ parts. Furthermore, complexes <b>1</b> and <b>2</b> exhibited absorption tails up to a much longer wavelength region of ca. 700 nm, suggesting the appearance of charge transfer absorption from TTF to the Mq₂ parts. The photoelectrochemical measurements on the thin films of these complexes casted on ITO-coated glass substrates suggest that positive photocurrents can be generated by the photoinduced intramolecular electron transfer process between the TTF and Mq₂ parts.