Chelation of transition metal ions by peptide nanoring

Shuichiro Kihara, Hiroyuki Takagi, Kazumasa Takechi, Kyozaburo Takeda

    Research output: Contribution to journalArticle

    7 Citations (Scopus)

    Abstract

    We have computationally studied the energetics and electronic structures of a chelate system where the guest cation is a transition metal (TM) and the host ligand is a peptide nanoring (PNR). The trapping of a TM cation by a cyclic peptide skeleton is primarily caused by the electrostatic interaction. The exchange interaction plays a secondary role in determining the relative stability in accordance with the spin multiplicity. An interesting feature of this chelate system is that a TM cation can also be trapped by the side-chain aromatic groups of the PNR via π-d hybridization. However, the spin multiplicity of the system changes the trapped form. When the chelate system has spin singlet multiplicity, a Fe2+ cation, for example, is not trapped by the single-phenyl group but is preferentially sandwiched by the two phenyl groups. In contrast, a Fe2+ cation can be trapped by single as well as by double-phenyl groups when the chelate system has higher spin multiplicity, such as triplet and quintet. These two different trapping forms are caused by the difference in the number of valence electrons of TM cations. For this chelate system, the newly occupied molecular orbital (MO) has an interbenzene antibonding character. Therefore, an electron occupying this MO state favors the mutual separation of two benzene molecules. Because the electron occupation of this MO varies in accordance with the spin multiplicity, one can predict the preference for the single-phenyl-group trapping process rather than the double-phenyl-group process systematically as well as consistently.

    Original languageEnglish
    Pages (from-to)7631-7644
    Number of pages14
    JournalJournal of Physical Chemistry B
    Volume112
    Issue number25
    DOIs
    Publication statusPublished - 2008 Jun 26

    Fingerprint

    Nanorings
    chelation
    Chelation
    Peptides
    peptides
    Transition metals
    Metal ions
    Cations
    metal ions
    chelates
    Positive ions
    transition metals
    cations
    Molecular orbitals
    molecular orbitals
    trapping
    Electrons
    Cyclic Peptides
    electrons
    Exchange interactions

    ASJC Scopus subject areas

    • Physical and Theoretical Chemistry
    • Materials Chemistry
    • Surfaces, Coatings and Films

    Cite this

    Chelation of transition metal ions by peptide nanoring. / Kihara, Shuichiro; Takagi, Hiroyuki; Takechi, Kazumasa; Takeda, Kyozaburo.

    In: Journal of Physical Chemistry B, Vol. 112, No. 25, 26.06.2008, p. 7631-7644.

    Research output: Contribution to journalArticle

    Kihara, Shuichiro ; Takagi, Hiroyuki ; Takechi, Kazumasa ; Takeda, Kyozaburo. / Chelation of transition metal ions by peptide nanoring. In: Journal of Physical Chemistry B. 2008 ; Vol. 112, No. 25. pp. 7631-7644.
    @article{4c9302e23dba4ab987a8bd0e60c1e285,
    title = "Chelation of transition metal ions by peptide nanoring",
    abstract = "We have computationally studied the energetics and electronic structures of a chelate system where the guest cation is a transition metal (TM) and the host ligand is a peptide nanoring (PNR). The trapping of a TM cation by a cyclic peptide skeleton is primarily caused by the electrostatic interaction. The exchange interaction plays a secondary role in determining the relative stability in accordance with the spin multiplicity. An interesting feature of this chelate system is that a TM cation can also be trapped by the side-chain aromatic groups of the PNR via π-d hybridization. However, the spin multiplicity of the system changes the trapped form. When the chelate system has spin singlet multiplicity, a Fe2+ cation, for example, is not trapped by the single-phenyl group but is preferentially sandwiched by the two phenyl groups. In contrast, a Fe2+ cation can be trapped by single as well as by double-phenyl groups when the chelate system has higher spin multiplicity, such as triplet and quintet. These two different trapping forms are caused by the difference in the number of valence electrons of TM cations. For this chelate system, the newly occupied molecular orbital (MO) has an interbenzene antibonding character. Therefore, an electron occupying this MO state favors the mutual separation of two benzene molecules. Because the electron occupation of this MO varies in accordance with the spin multiplicity, one can predict the preference for the single-phenyl-group trapping process rather than the double-phenyl-group process systematically as well as consistently.",
    author = "Shuichiro Kihara and Hiroyuki Takagi and Kazumasa Takechi and Kyozaburo Takeda",
    year = "2008",
    month = "6",
    day = "26",
    doi = "10.1021/jp800367c",
    language = "English",
    volume = "112",
    pages = "7631--7644",
    journal = "Journal of Physical Chemistry B Materials",
    issn = "1520-6106",
    publisher = "American Chemical Society",
    number = "25",

    }

    TY - JOUR

    T1 - Chelation of transition metal ions by peptide nanoring

    AU - Kihara, Shuichiro

    AU - Takagi, Hiroyuki

    AU - Takechi, Kazumasa

    AU - Takeda, Kyozaburo

    PY - 2008/6/26

    Y1 - 2008/6/26

    N2 - We have computationally studied the energetics and electronic structures of a chelate system where the guest cation is a transition metal (TM) and the host ligand is a peptide nanoring (PNR). The trapping of a TM cation by a cyclic peptide skeleton is primarily caused by the electrostatic interaction. The exchange interaction plays a secondary role in determining the relative stability in accordance with the spin multiplicity. An interesting feature of this chelate system is that a TM cation can also be trapped by the side-chain aromatic groups of the PNR via π-d hybridization. However, the spin multiplicity of the system changes the trapped form. When the chelate system has spin singlet multiplicity, a Fe2+ cation, for example, is not trapped by the single-phenyl group but is preferentially sandwiched by the two phenyl groups. In contrast, a Fe2+ cation can be trapped by single as well as by double-phenyl groups when the chelate system has higher spin multiplicity, such as triplet and quintet. These two different trapping forms are caused by the difference in the number of valence electrons of TM cations. For this chelate system, the newly occupied molecular orbital (MO) has an interbenzene antibonding character. Therefore, an electron occupying this MO state favors the mutual separation of two benzene molecules. Because the electron occupation of this MO varies in accordance with the spin multiplicity, one can predict the preference for the single-phenyl-group trapping process rather than the double-phenyl-group process systematically as well as consistently.

    AB - We have computationally studied the energetics and electronic structures of a chelate system where the guest cation is a transition metal (TM) and the host ligand is a peptide nanoring (PNR). The trapping of a TM cation by a cyclic peptide skeleton is primarily caused by the electrostatic interaction. The exchange interaction plays a secondary role in determining the relative stability in accordance with the spin multiplicity. An interesting feature of this chelate system is that a TM cation can also be trapped by the side-chain aromatic groups of the PNR via π-d hybridization. However, the spin multiplicity of the system changes the trapped form. When the chelate system has spin singlet multiplicity, a Fe2+ cation, for example, is not trapped by the single-phenyl group but is preferentially sandwiched by the two phenyl groups. In contrast, a Fe2+ cation can be trapped by single as well as by double-phenyl groups when the chelate system has higher spin multiplicity, such as triplet and quintet. These two different trapping forms are caused by the difference in the number of valence electrons of TM cations. For this chelate system, the newly occupied molecular orbital (MO) has an interbenzene antibonding character. Therefore, an electron occupying this MO state favors the mutual separation of two benzene molecules. Because the electron occupation of this MO varies in accordance with the spin multiplicity, one can predict the preference for the single-phenyl-group trapping process rather than the double-phenyl-group process systematically as well as consistently.

    UR - http://www.scopus.com/inward/record.url?scp=48149089019&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=48149089019&partnerID=8YFLogxK

    U2 - 10.1021/jp800367c

    DO - 10.1021/jp800367c

    M3 - Article

    C2 - 18528971

    AN - SCOPUS:48149089019

    VL - 112

    SP - 7631

    EP - 7644

    JO - Journal of Physical Chemistry B Materials

    JF - Journal of Physical Chemistry B Materials

    SN - 1520-6106

    IS - 25

    ER -