Synthesis and characterization of nickel dithiocarbamate complexes bearing ferrocenyl subunits

Kenichi Oyaizu, Kimihisa Yamamoto, Yurie Ishii, Eishun Tsuchida

    Research output: Contribution to journalArticle

    16 Citations (Scopus)

    Abstract

    Syntheses of a unique molecule, nickel(II) dithiocarbamate bearing two ferrocenyl groups (3), and its oxidized product, nickel(IV) dithiocarbamate bearing three ferrocenyl groups (4+), are reported. Spectroelectrochemical investigations have shown that the complex 4+ undergoes a three-electron oxidation process, according to two quasireversible steps ([NiIV(FeII)3]+⇌ [NiIV(FeII)2FeIII] 2++e-, [NiIV(FeII)2-FeIII]2+ ⇌ [NiIV(FeIII)3]4++2e-), whose redox potentials are separated by ΔE = 250 mV. The value ΔE is related to the comproportionation equilibrium ([NiIV(FeII)3]++[Ni IV(FeIII)2FeII]3+⇌ 2 [NiIVFeIII(FeII)2]2+) and results from the combination of a statistical contribution and a term which reflects the electrostatic repulsive interaction between the metal centers. In spite of the chemical equivalence of the three ferrocenyl groups, the mixed-valence state [NiIV-FeIII(FeII)2]2+ (42+) substantially persists in solution. Model studies with ethylenebridged bis(ferrocenylimine) (6) have revealed that the electrostatic term is much lower in the absence of the nickel(IV) center. Preliminary force-field simulations on 4+ have shown that enhanced electrostatic repulsion caused by the oxidation of the ferrocenyl subunits affects the conformation of the molecule, which results in a significant dimensional increment. Stereochemical features of the molecules are related to the electrostatic interaction and ΔG0 associated with the comproportionation process is affected by such strong deformation that a decrease in electrostatic repulsion results.

    Original languageEnglish
    Pages (from-to)3193-3201
    Number of pages9
    JournalChemistry - A European Journal
    Volume5
    Issue number11
    Publication statusPublished - 1999 Nov

    Fingerprint

    Bearings (structural)
    Nickel
    Electrostatics
    Coulomb interactions
    Molecules
    Selegiline
    Oxidation
    Conformations
    Metals
    Electrons

    Keywords

    • Electrochemistry
    • Metallocenes
    • N ligands
    • Nickel
    • S ligands
    • Sandwich complexes

    ASJC Scopus subject areas

    • Chemistry(all)

    Cite this

    Synthesis and characterization of nickel dithiocarbamate complexes bearing ferrocenyl subunits. / Oyaizu, Kenichi; Yamamoto, Kimihisa; Ishii, Yurie; Tsuchida, Eishun.

    In: Chemistry - A European Journal, Vol. 5, No. 11, 11.1999, p. 3193-3201.

    Research output: Contribution to journalArticle

    Oyaizu, Kenichi ; Yamamoto, Kimihisa ; Ishii, Yurie ; Tsuchida, Eishun. / Synthesis and characterization of nickel dithiocarbamate complexes bearing ferrocenyl subunits. In: Chemistry - A European Journal. 1999 ; Vol. 5, No. 11. pp. 3193-3201.
    @article{354f8c3fae784a76aa764fe9f8b4c61e,
    title = "Synthesis and characterization of nickel dithiocarbamate complexes bearing ferrocenyl subunits",
    abstract = "Syntheses of a unique molecule, nickel(II) dithiocarbamate bearing two ferrocenyl groups (3), and its oxidized product, nickel(IV) dithiocarbamate bearing three ferrocenyl groups (4+), are reported. Spectroelectrochemical investigations have shown that the complex 4+ undergoes a three-electron oxidation process, according to two quasireversible steps ([NiIV(FeII)3]+⇌ [NiIV(FeII)2FeIII] 2++e-, [NiIV(FeII)2-FeIII]2+ ⇌ [NiIV(FeIII)3]4++2e-), whose redox potentials are separated by ΔE = 250 mV. The value ΔE is related to the comproportionation equilibrium ([NiIV(FeII)3]++[Ni IV(FeIII)2FeII]3+⇌ 2 [NiIVFeIII(FeII)2]2+) and results from the combination of a statistical contribution and a term which reflects the electrostatic repulsive interaction between the metal centers. In spite of the chemical equivalence of the three ferrocenyl groups, the mixed-valence state [NiIV-FeIII(FeII)2]2+ (42+) substantially persists in solution. Model studies with ethylenebridged bis(ferrocenylimine) (6) have revealed that the electrostatic term is much lower in the absence of the nickel(IV) center. Preliminary force-field simulations on 4+ have shown that enhanced electrostatic repulsion caused by the oxidation of the ferrocenyl subunits affects the conformation of the molecule, which results in a significant dimensional increment. Stereochemical features of the molecules are related to the electrostatic interaction and ΔG0 associated with the comproportionation process is affected by such strong deformation that a decrease in electrostatic repulsion results.",
    keywords = "Electrochemistry, Metallocenes, N ligands, Nickel, S ligands, Sandwich complexes",
    author = "Kenichi Oyaizu and Kimihisa Yamamoto and Yurie Ishii and Eishun Tsuchida",
    year = "1999",
    month = "11",
    language = "English",
    volume = "5",
    pages = "3193--3201",
    journal = "Chemistry - A European Journal",
    issn = "0947-6539",
    publisher = "Wiley-VCH Verlag",
    number = "11",

    }

    TY - JOUR

    T1 - Synthesis and characterization of nickel dithiocarbamate complexes bearing ferrocenyl subunits

    AU - Oyaizu, Kenichi

    AU - Yamamoto, Kimihisa

    AU - Ishii, Yurie

    AU - Tsuchida, Eishun

    PY - 1999/11

    Y1 - 1999/11

    N2 - Syntheses of a unique molecule, nickel(II) dithiocarbamate bearing two ferrocenyl groups (3), and its oxidized product, nickel(IV) dithiocarbamate bearing three ferrocenyl groups (4+), are reported. Spectroelectrochemical investigations have shown that the complex 4+ undergoes a three-electron oxidation process, according to two quasireversible steps ([NiIV(FeII)3]+⇌ [NiIV(FeII)2FeIII] 2++e-, [NiIV(FeII)2-FeIII]2+ ⇌ [NiIV(FeIII)3]4++2e-), whose redox potentials are separated by ΔE = 250 mV. The value ΔE is related to the comproportionation equilibrium ([NiIV(FeII)3]++[Ni IV(FeIII)2FeII]3+⇌ 2 [NiIVFeIII(FeII)2]2+) and results from the combination of a statistical contribution and a term which reflects the electrostatic repulsive interaction between the metal centers. In spite of the chemical equivalence of the three ferrocenyl groups, the mixed-valence state [NiIV-FeIII(FeII)2]2+ (42+) substantially persists in solution. Model studies with ethylenebridged bis(ferrocenylimine) (6) have revealed that the electrostatic term is much lower in the absence of the nickel(IV) center. Preliminary force-field simulations on 4+ have shown that enhanced electrostatic repulsion caused by the oxidation of the ferrocenyl subunits affects the conformation of the molecule, which results in a significant dimensional increment. Stereochemical features of the molecules are related to the electrostatic interaction and ΔG0 associated with the comproportionation process is affected by such strong deformation that a decrease in electrostatic repulsion results.

    AB - Syntheses of a unique molecule, nickel(II) dithiocarbamate bearing two ferrocenyl groups (3), and its oxidized product, nickel(IV) dithiocarbamate bearing three ferrocenyl groups (4+), are reported. Spectroelectrochemical investigations have shown that the complex 4+ undergoes a three-electron oxidation process, according to two quasireversible steps ([NiIV(FeII)3]+⇌ [NiIV(FeII)2FeIII] 2++e-, [NiIV(FeII)2-FeIII]2+ ⇌ [NiIV(FeIII)3]4++2e-), whose redox potentials are separated by ΔE = 250 mV. The value ΔE is related to the comproportionation equilibrium ([NiIV(FeII)3]++[Ni IV(FeIII)2FeII]3+⇌ 2 [NiIVFeIII(FeII)2]2+) and results from the combination of a statistical contribution and a term which reflects the electrostatic repulsive interaction between the metal centers. In spite of the chemical equivalence of the three ferrocenyl groups, the mixed-valence state [NiIV-FeIII(FeII)2]2+ (42+) substantially persists in solution. Model studies with ethylenebridged bis(ferrocenylimine) (6) have revealed that the electrostatic term is much lower in the absence of the nickel(IV) center. Preliminary force-field simulations on 4+ have shown that enhanced electrostatic repulsion caused by the oxidation of the ferrocenyl subunits affects the conformation of the molecule, which results in a significant dimensional increment. Stereochemical features of the molecules are related to the electrostatic interaction and ΔG0 associated with the comproportionation process is affected by such strong deformation that a decrease in electrostatic repulsion results.

    KW - Electrochemistry

    KW - Metallocenes

    KW - N ligands

    KW - Nickel

    KW - S ligands

    KW - Sandwich complexes

    UR - http://www.scopus.com/inward/record.url?scp=0032722881&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=0032722881&partnerID=8YFLogxK

    M3 - Article

    AN - SCOPUS:0032722881

    VL - 5

    SP - 3193

    EP - 3201

    JO - Chemistry - A European Journal

    JF - Chemistry - A European Journal

    SN - 0947-6539

    IS - 11

    ER -