Redox Properties of a Mononuclear Copper(II)-Superoxide Complex.
In: Inorganic Chemistry, Jg. 52 (2013-09-16), Heft 18, S. 10431-10437
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Zugriff:
Redox properties of a mononuclear copper(II) superoxide complex, (L)CuII-OO·, supported by a tridentate ligand (L = 1-(2-phenethyl)-5-[2-(2-pyridyl)ethyl]-1,5-diazacyclooctane) have been examined as a model compound of the putative reactive intermediate of peptidylglycine a-hydroxylating monooxygenase (PHM) and dopamine β-monooxygenase (DβM) (Kunishita et al. J. Am. Chem. Soc. 2009, 131, 2788-2789; Inorg. Chem. 2012, 51, 9465-9480). On the basis of the reactivity toward a series of one-electron reductants, the reduction potential of (L)CuII-OO· was estimated to be 0.19 ± 0.07 V vs SCE in acetone at 298 K (cf. Tahsini et al. Chem.--Eur. J. 2012, 18, 1084-1093). In the reaction of TEMPO-H (2,2,6,6-tetramethylpiperidine-N-hydroxide), a simple HAT (hydrogen atom transfer) reaction took place to give the corresponding hydroperoxide complex LCuII-OOH, whereas the reaction with phenol derivatives (XArOH) gave the corresponding phenolate adducts, LCuII-OXAr, presumably via an acid-base reaction between the superoxide ligand and the phenols. The reaction of (L)CuII-OO· with a series of triphenylphosphine derivatives gave the corresponding triphenylphosphine oxides via an electrophilic ionic substitution mechanism with a Hammett ρ value as -4.3, whereas the reaction with thioanisole (sulfide) only gave a copper(I) complex. These reactivities of (L)CuII-OO· are different from those of a similar end-on superoxide copper(II) complex supported by a tetradentate TMG3tren ligand (1,1,1-Tris{2-[N²-(1,1,3,3-tetramethylguanidino)]ethyl}amine (Maiti et al. Angew. Chem., Int. Ed. 2008, 47, 82-85). [ABSTRACT FROM AUTHOR]
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Redox Properties of a Mononuclear Copper(II)-Superoxide Complex.
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Autor/in / Beteiligte Person: | Tano, Tetsuro ; Okubo, Yuri ; Kunishita, Atsushi ; Kubo, Minoru ; Sugimoto, Hideki ; Fujieda, Nobutaka ; Ogura, Takashi ; Itoh, Shinobu |
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Zeitschrift: | Inorganic Chemistry, Jg. 52 (2013-09-16), Heft 18, S. 10431-10437 |
Veröffentlichung: | 2013 |
Medientyp: | academicJournal |
ISSN: | 0020-1669 (print) |
DOI: | 10.1021/ic401261z |
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