Electrochemical Behavior of [Cp′2Fe2S4] and [Cp′2Fe2S4](PF6)2 (Cp′ = η5-C5Me5): Structural Change of the Fe2S4 Core Accompanied by a Change of Redox State

Shinji Inomata, Hiromi Tobita, Hiroshi Ogino

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)

Abstract

Bulk electrolysis of Cp′2Fe2S4 in 0.1 M NH4PF6 in CH3CN at a peak potential for a one-electron-oxidation wave (+0.30 V vs SCE) gives a two-electron-oxidation product [Cp′2Fe2S4](PF6)2 in high yield, where an Fe2S4 core with a bidentate and a doubly bidentate μ-S2 ligands in the neutral species (A type species) changes to one with two doubly bidentate μ-S2 ligands in the dicationic species (B type species) during oxidation. Electrochemical and spectroscopic studies on the redox behavior of these neutral and dicationic species have shown that a total of six species, i.e. a neutral complex, a monocation, and a dication with A-type cores and the same with B-type cores, participate in the redox reactions between [Cp′2Fe2S4] and [C′2Fe2S4](PF6)2. The one-electron-oxidation potential of [Cp′2Fe2S4] (E1/2 = +0.25 V vs SCE) is more positive than the one-electron-reduction potential of [Cp′2Fe2S4](PF6)2 (E1/2 = +0.15 V vs SCE), and the interconversion between A and B geometries of the Fe2S4 core is fast for monocations. Thus, an ECE-type process operates for the formation of [Cp′2Fe2S4](PF6)2 from [Cp′2Fe2S4]. The equilibrium constant for the electron transfer between [Cp′2Fe2S4] and [Cp′2Fe2S4](PF6)2 has been estimated.

Original languageEnglish
Pages (from-to)3039-3043
Number of pages5
JournalInorganic Chemistry
Volume30
Issue number15
DOIs
Publication statusPublished - 1991 Jul 1

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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