Decomposition and isomerization mechanisms of head-to-head α-pyridonato-bridged ethylenediamineplatinum(II) binuclear complex, [Pt2(en)2(C5H4NO)2]2+, in aqueous solution

Yuuki Ito; Kohei Yamashima; Shintaro Arai; Makoto Takahashi; Tomohiro Itou; Satoshi Iwatsuki; Koji Ishihara; Kazuko Matsumoto

doi:10.1016/j.ica.2020.119934

Decomposition and isomerization mechanisms of head-to-head α-pyridonato-bridged ethylenediamineplatinum(II) binuclear complex, [Pt₂(en)₂(C₅H₄NO)₂]²⁺, in aqueous solution

Yuuki Ito, Kohei Yamashima, Shintaro Arai, Makoto Takahashi, Tomohiro Itou, Satoshi Iwatsuki^*, Koji Ishihara, Kazuko Matsumoto

^*Corresponding author for this work

School of Advanced Science and Engineering

Research output: Contribution to journal › Article › peer-review

1 Citation (Scopus)

Abstract

The isomerization reaction of the head-to-head α-pyridonato-bridged ethylenediamineplatinum(II) binuclear complex (HH-[Pt₂(en)₂(α-pyridonato)₂]²⁺, HH dimer) to the head-to-tail isomer and the decomposition reactions of the HH and HT dimers to monomers in aqueous solution were studied in detail at various pH values using ¹H NMR. It was found that the isomerization reaction proceeded preferentially at pH ~ 7. In contrast, the isomerization reaction and decomposition reactions preferentially proceeded at lower pH. An initial Pt–O (α-pyridonate) bond-breaking mechanism was proposed for both the isomerization and the acid-decomposition reactions based on the acid dependency of the detected reaction intermediate. The protonation of the dissociated oxygen atom of the monodentated α-pyridonate in the intermediate plays a vital role in determining isomerization or decomposition.

Original language	English
Article number	119934
Journal	Inorganica Chimica Acta
Volume	513
DOIs	https://doi.org/10.1016/j.ica.2020.119934
Publication status	Published - 2020 Dec 1

Keywords

Acid decomposition
Binuclear complex
Isomerization
Platinum
Pyridonate

ASJC Scopus subject areas

Physical and Theoretical Chemistry
Inorganic Chemistry
Materials Chemistry

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10.1016/j.ica.2020.119934

Cite this

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title = "Decomposition and isomerization mechanisms of head-to-head α-pyridonato-bridged ethylenediamineplatinum(II) binuclear complex, [Pt2(en)2(C5H4NO)2]2+, in aqueous solution",

abstract = "The isomerization reaction of the head-to-head α-pyridonato-bridged ethylenediamineplatinum(II) binuclear complex (HH-[Pt2(en)2(α-pyridonato)2]2+, HH dimer) to the head-to-tail isomer and the decomposition reactions of the HH and HT dimers to monomers in aqueous solution were studied in detail at various pH values using 1H NMR. It was found that the isomerization reaction proceeded preferentially at pH ~ 7. In contrast, the isomerization reaction and decomposition reactions preferentially proceeded at lower pH. An initial Pt–O (α-pyridonate) bond-breaking mechanism was proposed for both the isomerization and the acid-decomposition reactions based on the acid dependency of the detected reaction intermediate. The protonation of the dissociated oxygen atom of the monodentated α-pyridonate in the intermediate plays a vital role in determining isomerization or decomposition.",

keywords = "Acid decomposition, Binuclear complex, Isomerization, Platinum, Pyridonate",

author = "Yuuki Ito and Kohei Yamashima and Shintaro Arai and Makoto Takahashi and Tomohiro Itou and Satoshi Iwatsuki and Koji Ishihara and Kazuko Matsumoto",

note = "Funding Information: This work was supported in part by JSPS KAKENHI ( 18K05187 to S. I. and 17K05910 to K.I.) and a grant from the Hyogo Science and Technology Association (to S. I.). We would like to thank Editage ( www.editage.jp ) for English language editing. Publisher Copyright: {\textcopyright} 2020 Elsevier B.V.",

year = "2020",

month = dec,

day = "1",

doi = "10.1016/j.ica.2020.119934",

language = "English",

volume = "513",

journal = "Inorganica Chimica Acta",

issn = "0020-1693",

publisher = "Elsevier BV",

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TY - JOUR

T1 - Decomposition and isomerization mechanisms of head-to-head α-pyridonato-bridged ethylenediamineplatinum(II) binuclear complex, [Pt2(en)2(C5H4NO)2]2+, in aqueous solution

AU - Ito, Yuuki

AU - Yamashima, Kohei

AU - Arai, Shintaro

AU - Takahashi, Makoto

AU - Itou, Tomohiro

AU - Iwatsuki, Satoshi

AU - Ishihara, Koji

AU - Matsumoto, Kazuko

N1 - Funding Information: This work was supported in part by JSPS KAKENHI ( 18K05187 to S. I. and 17K05910 to K.I.) and a grant from the Hyogo Science and Technology Association (to S. I.). We would like to thank Editage ( www.editage.jp ) for English language editing. Publisher Copyright: © 2020 Elsevier B.V.

PY - 2020/12/1

Y1 - 2020/12/1

N2 - The isomerization reaction of the head-to-head α-pyridonato-bridged ethylenediamineplatinum(II) binuclear complex (HH-[Pt2(en)2(α-pyridonato)2]2+, HH dimer) to the head-to-tail isomer and the decomposition reactions of the HH and HT dimers to monomers in aqueous solution were studied in detail at various pH values using 1H NMR. It was found that the isomerization reaction proceeded preferentially at pH ~ 7. In contrast, the isomerization reaction and decomposition reactions preferentially proceeded at lower pH. An initial Pt–O (α-pyridonate) bond-breaking mechanism was proposed for both the isomerization and the acid-decomposition reactions based on the acid dependency of the detected reaction intermediate. The protonation of the dissociated oxygen atom of the monodentated α-pyridonate in the intermediate plays a vital role in determining isomerization or decomposition.

AB - The isomerization reaction of the head-to-head α-pyridonato-bridged ethylenediamineplatinum(II) binuclear complex (HH-[Pt2(en)2(α-pyridonato)2]2+, HH dimer) to the head-to-tail isomer and the decomposition reactions of the HH and HT dimers to monomers in aqueous solution were studied in detail at various pH values using 1H NMR. It was found that the isomerization reaction proceeded preferentially at pH ~ 7. In contrast, the isomerization reaction and decomposition reactions preferentially proceeded at lower pH. An initial Pt–O (α-pyridonate) bond-breaking mechanism was proposed for both the isomerization and the acid-decomposition reactions based on the acid dependency of the detected reaction intermediate. The protonation of the dissociated oxygen atom of the monodentated α-pyridonate in the intermediate plays a vital role in determining isomerization or decomposition.

KW - Acid decomposition

KW - Binuclear complex

KW - Isomerization

KW - Platinum

KW - Pyridonate

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