Spin Transition in a Manganese(III) Porphyrin Cation Radical, Its Transformation to a Dichloromanganese(IV) Porphyrin, and Chlorination of Hydrocarbons by the Latter

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• 作者：Lilia Kaustov ; Merav E. Tal ; Alexander I. Shames ; and Zeev Gross
• 刊名：Inorganic Chemistry
• 出版年：1997
• 出版时间：July 30, 1997
• 年：1997
• 卷：36
• 期：16
• 页码：3503 - 3511
• 全文大小：260K
• 年卷期：v.36,no.16(July 30, 1997)
• ISSN：1520-510X

文摘

Chemical oxidation of (TMP)Mn^III(Cl) (TMP= the tetramesitylporphyrinato dianion) byFe(ClO₄)₃ leads to theporphyrin-oxidized product(TMP^{images/entities/bull.gif">+})Mn^III(ClO₄)₂.Magnetic measurements and EPR spectroscopy show thatthetotal spin of the complex changes from S =⁵/₂ at high temperature to S =³/₂ at low temperature. Ligandexchangeof the perchlorato ligands in(TMP^{images/entities/bull.gif">+})Mn^III(ClO₄)₂by chloride anions is accompanied by a change of theoxidationsite from porphyrin to metal, resulting in(TMP)Mn^IV(Cl)₂. Thishigh-valent-metal complex can effect chlorineatom transfer to olefins, as well as to dimedone and chlorodimedone,natural substrates of chloroperoxidases.