title: π-Conjugated trinuclear group-9 metalladithiolenes with a triphenylene backbone.
abstract: Previously, we synthesized π-conjugated trinuclear metalladithiolene complexes based on benzenehexathiol (J. Chem. Soc., Dalton Trans.1998, 2651; Dalton Trans.2009, 1939; Inorg. Chem.2011, 50, 6856). Here we report trinuclear complexes with a triphenylene backbone. A reaction with triphenylenehexathiol and group 9 metal precursors in the presence of triethylamine gives rise to trinuclear complexes 9-11. The planar structure of 11 is determined using single crystal X-ray diffraction analysis. The ligand-to-metal charge transfer bands of 9-11 move to longer wavelengths compared with those of mononuclear 12-14. Electrochemical measurements disclose that the one-electron and two-electron reduced mixed-valent states are stabilized thermodynamically. UV-vis-NIR spectroscopy for the reduced species of 9 identifies intervalence charge transfer bands for 9(-) and 9(2-), substantiating the existence of electronic communication among the three metal nuclei. These observations prove that the triphenylene backbone transmits π-conjugation among the three metalladithiolene units.
authors.affiliation: Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Tokyo 113-0033, Japan. sakamoto@chem.s.u-tokyo.ac.jp
authors.forename: Ryota
authors.initials: R
authors.lastname: Sakamoto
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kambe
authors.forename: Satoru
authors.initials: S
authors.lastname: Tsukada
authors.forename: Kenji
authors.initials: K
authors.lastname: Takada
authors.forename: Ken
authors.initials: K
authors.lastname: Hoshiko
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Okumura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishihara