Dioxygen Binding to a Cobalt(II) Porphycene Complex and Its Auto-Oxidized Cobalt(III) Complex

• Hisashi Shimakoshi

  Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University

• Isao Aritome

  Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University

• Shun Hirota

  Department of Physical Chemistry, Kyoto Pharmaceutical University

• Yoshio Hisaeda

  Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University

抄録

The reaction between a cobalt porphycene complex, [CoII(TPrPc)] (TPrPc is a dianion of 2,7,12,17-tetrapropylporphycene), and dioxygen was investigated by means of UV–vis, ESR, and resonance Raman (RR) spectroscopies. These spectra indicate the formation of [CoIII–O2−•]. In the presence of pyridine as an axial ligand, the formation of a six-coordinated superoxide species was confirmed by its characteristic ESR spectrum. The six-coordinated dioxygen adduct exhibits an RR band at 1144 cm−1, which is characteristic of O–O stretching of superoxide. ν(Co–O2) stretching is also observed at 540 cm−1. The ν(O–O) and ν(Co–O2) wavenumbers in the complex were assigned by means of 18O2 substitution. ν(Co–O2) of the O2 adduct shows a higher frequency relative to those of cobalt porphyrin complexes. On standing for one day at room temperature, the compound was auto-oxidized to a CoIII complex, which was structurally determined by X-ray analysis. The complex crystallized in the monoclinic space group P21/n, a = 9.6266(4) Å, b = 12.6343(5) Å, c = 15.6566(6) Å, β = 99.1200(10)°, V = 1880.17(13) Å3, and Z = 2. The CoIII ion lies on the plane of the porphycenato core, and coordinates four porphycenato nitrogen atoms and two pyridine nitrogen atoms. The complex cation, [CoIII(TPrPc)(Py)2]+, exhibits a slightly distorted octahedral coordination geometry. The average Co–N (porphycenato pyrrole) distance and the Co–N (pyridine) distance are 1.929 and 1.952 Å, respectively.

収録刊行物

• Bulletin of the Chemical Society of Japan

  Bulletin of the Chemical Society of Japan 78 (9), 1619-1623, 2005-08-30

  Oxford University Press (OUP)

キーワード

• General Chemistry

詳細情報

• CRID: 1360565169058466944
• NII論文ID: 130004151970
• DOI: 10.1246/bcsj.78.1619
• ISSN: 13480634
• ISSN: 00092673
• Web Site: https://academic.oup.com/bcsj/article-pdf/78/9/1619/56266333/bcsj.78.1619.pdf
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