1453484-64-4Relevant academic research and scientific papers
Redox properties of a mononuclear copper(II)-superoxide complex
Tano, Tetsuro,Okubo, Yuri,Kunishita, Atsushi,Kubo, Minoru,Sugimoto, Hideki,Fujieda, Nobutaka,Ogura, Takashi,Itoh, Shinobu
, p. 10431 - 10437 (2013/10/01)
Redox properties of a mononuclear copper(II) superoxide complex, (L)Cu II-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 α-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, LCu II-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 TMG 3tren 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).
