Shiduko Nakajo

Synthesis, structure, and one-electron redox reactions of 4,7-disubstituted benzotrichalcogenoles containing sulfur and/or selenium atoms

Abstract Stable 4,7-disubstituted benzotrichalcogenoles containing sulfur and/or selenium atoms in the five-membered ring were systematically and selectively prepared in good yields by reaction of the corresponding benzodichalcogenastannoles, a synthetic equivalent of benzenedichalcogenols, with an S 1 or Se 1 source. Characterization of these new trichalcogenole frameworks was performed by multi-nuclear NMR studies and X-ray crystallographic analyses. The cyclic voltammograms of the trichalcogenoles showed well-defined reversible electrochemical redox couples with low oxidation potential. Novel radical ions were isolated in quantitative yields in the one-electron oxidation of the trichalcogenoles with one equivalent of NOPF 6 as a one-electron oxidant. The structures of the radical cation salts were analyzed by 31 P-NMR and EPR spectroscopies, and elemental analyses. The salts underwent one-electron reduction on treatment with one equivalent of samarium(II) iodide to give the neutral starting trichalcogenoles quantitatively.

Synthesis, structure, and electrochemical properties of [2.2]paracyclophane[4,5-d]trithiole

A novel five-membered trithiole with sulfur–sulfur linkages bound to a [2.2] paracyclophane framework with low-redox potential has been synthesized. Characterization of the new trithiole was performed by X-ray crystallographic analysis. The cyclic voltammogram of the trithiole showed well-defined reversible electrochemical redox coupled with low-oxidation potential. Novel radical cation salt was isolated in quantitative yield in the one-electron oxidation of the trithiole with one equivalent of NOPF6 as a one-electron oxidant. The structure of the radical cation salt was analyzed by 31P NMR and EPR spectroscopies and elemental analysis. The salt underwent one-electron reduction on treatment with one equivalent of samarium(II) iodide to give the neutral starting trithiole quantitatively.

Preparation of phthalocyanines fused with four tetrathiafulvalene units via the functional group transformation of tetrakis(o-xylylenedithio)phthalocyanines with toluene/aluminum chloride

Tetrakis(o-xylylenedithio)phthalocyanine 5 and its nickel complex 5-Ni were treated with aluminum chloride in toluene to eliminate the peripheral o-xylylene groups. The thiolate anions generated from 5 and 5-Ni were reacted with carbonyldiimidazole to produce phthalocyanines 6 and 6-Ni with four 1,3-dithiole-2-one rings, respectively. Phthalocyanine 7a having four ethylenedithiotetrathiafulvalene units was prepared via the condensation of 6-Ni with ethylenedithio-1,3-dithiole-2-thiones. The reaction of 6-Ni with bis(methylthio)-1,3-dithiole-2-thiones gave phthalocyanine 7b with the corresponding TTF units. The structures of the products were determined by 1H NMR and MALDI-TOF-MS. Their electrochemical and optical properties were examined by cyclic voltammetry and UV-vis spectroscopy.