Proton-induced tuning of metal-metal communication in rack-type dinuclear Ru complexes containing benzimidazolyl moieties

Katsuaki Kobayashi, Masamichi Ishikubo, Katsuhiko Kanaizuka, Keiko Kosuge, Shigeyuki Masaoka, Ken Sakai, Koichi Nozaki, Masa Aki Haga

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Abstract

Ru complexes bearing a bis-tridentate benzimidazolyl ligand have been synthesized. The dinuclear ones act as a bibasic acid with pKa1=4.36 and pKa2=5.90. The protonated form of the dinuclear complex exhibited two one-electron oxidations at +0.91 and +1.02V versus the ferrocenium/ ferrocene (Fc/Fc+) couple (the potential difference (ΔE)=0.11V), but the di-deprotonated form showed two waves at +0.50 and +0.58V versus Fc/Fc+ (ΔE=0.08V). Since the potential difference between two waves reflects the strength of the metal-metal interaction, the deprotonation of the benzimidazole moieties in the complexes weakened the Ru-Ru communication. The degree of electronic coupling between two metal centers, estimated from the intervalence charge transfer (IVCT) band, was greater for the protonated form. DFT calculations for the protonated and deprotonated forms of the dinuclear complex suggest that the RuII-L(H2) π* interaction plays a key role in the Ru-Ru interaction.

Original languageEnglish
Pages (from-to)6954-6963
Number of pages10
JournalChemistry - A European Journal
Volume17
Issue number25
DOIs
Publication statusPublished - Jun 14 2011

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Protons
Tuning
Metals
Communication
Bearings (structural)
Deprotonation
Discrete Fourier transforms
Charge transfer
Ligands
Oxidation
Acids
Electrons
benzimidazole
ferrocenium
ferrocene

All Science Journal Classification (ASJC) codes

  • Chemistry(all)

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Proton-induced tuning of metal-metal communication in rack-type dinuclear Ru complexes containing benzimidazolyl moieties. / Kobayashi, Katsuaki; Ishikubo, Masamichi; Kanaizuka, Katsuhiko; Kosuge, Keiko; Masaoka, Shigeyuki; Sakai, Ken; Nozaki, Koichi; Haga, Masa Aki.

In: Chemistry - A European Journal, Vol. 17, No. 25, 14.06.2011, p. 6954-6963.

Research output: Contribution to journalArticle

Kobayashi, Katsuaki ; Ishikubo, Masamichi ; Kanaizuka, Katsuhiko ; Kosuge, Keiko ; Masaoka, Shigeyuki ; Sakai, Ken ; Nozaki, Koichi ; Haga, Masa Aki. / Proton-induced tuning of metal-metal communication in rack-type dinuclear Ru complexes containing benzimidazolyl moieties. In: Chemistry - A European Journal. 2011 ; Vol. 17, No. 25. pp. 6954-6963.
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