Manganese(III) and manganese(IV) corroles: synthesis, spectroscopic, electrochemical and X-ray structural characterization

Abstract

The synthesis, spectroscopic characterization and electrochemistry of four Mn(III) and Mn(IV) octaethylcorroles are reported and the potentials of the Mn(III) / Mn(IV) and Mn(IV) / Mn(III) processes examined as a function of the axial ligand. The investigated compounds are represented as ( OEC ) Mn , ( OEC ) MnCl , ( OEC ) Mn ( py ) and ( OEC ) Mn ( C 6 H 5) where OEC is the trianion of octaethylcorrole. The first one-electron oxidation of ( OEC ) Mn III and ( OEC ) Mn III ( py ) in PhCN or pyridine containing 0.1 M TBAP leads to the facile formation of a Mn(IV) species while the first one-electron reduction of ( OEC ) Mn IV Cl and ( OEC ) Mn IV ( C 6 H 5) in the same two solvents leads to the Mn(III) corrole. All other redox reactions occur at the corrole macrocycle to give π-cation radicals or π-anion radicals and there is no evidence for electrogeneration of a compound with a Mn(II) oxidation state as is the case for manganese(III) porphyrins which are all easily reduced to the Mn(II) state in nonaqueous media. The products of each Mn(III)/Mn(IV) redox reaction were characterized by UV-visible and/or ESR spectroscopy and the structures of ( OEC ) MnCl , ( OEC ) Mn ( py ) and ( OEC ) Mn ( C 6 H 5) were determined by single-crystal X-ray diffraction.

A Reactive Manganese(IV)–Hydroxide Complex: A Missing Intermediate in Hydrogen Atom Transfer by High-Valent Metal-Oxo Porphyrinoid Compounds

“…The Mn IV –Cl distance of 2.2754(11) Å is similar to other Mn IV (Cl) corroles. 57–58 This complex served as starting material for preparation of the target Mn IV (OH) species.…”

Cobalt, Iron, and Manganese Metallocorroles in Catalytic Oxidation of Water. An Overview of the Synthesis, Selected Redox and Electronic Properties, and Catalytic Activities

“…This has worked well in our hands for corroles containing two or three 4-nitrophenyl, 2/4-methylcarboxyphenyl or pentafluorophenyl substituents. However, we have observed in some dried crystallization batches thin white needles which, after some investigation, were found to be a salt product of nucleophilic substitution of Mn(III)corrole [28] Corrole (0.098 mmol, 60 mg) + Mn(AcO) Mn(III)corrole(Py) [42] Mn(III)corrole (0.5 mmol, 287 mg) in Py Layer with MeOH Black crystals formed 95 Mn(IV)corrole(Cl) [42] Mn(III)corrole (0. (Mn(V)=O)corrole [43] Mn(III)corrole (5.5 μmol, 4.0 mg) and t-BuOOH (0.05 M, 1.36 eq.)…”

“…Molecular structures of some Mn corroles mentioned in Table 4. Mn(III)(oec) [42] 1 À 1.58 0.36 0.93 1.56 SCE PhCN À 2.08 À 0.04 0.53 1.16 Fc + /Fc Calc Mn(IV)Cl(oec) [42] 2 À 1.68 À 0.01 0.85 1.62 SCE PhCN À 2.18 À 0.41 0.45 1.22 Fc + /Fc Calc Mn(III)(tnpc)(Py) [64] 3 À 1.61 À 1.45 0.12 Fc + /Fc CH 2 Cl 2 Mn(Cl)corrole [70] 4 À 0.32 0.61 Ag/Ag + CH 2 Cl 2 (0.1 M Bu 4 NPF 6 ) À 0.82 0.11 Fc + /Fc Calc Mn(Cl)bis(corrole) [70] 5 À 0.33 0.58 0.70 Ag/Ag + CH 2 Cl 2 (0.1 M Bu 4 NPF 6 ) À 0.83 0.08 0.20 Fc + /Fc Calc Mn(TpFPCÀ SCO 2 ) [71] 7 0.53 0.78 Ag/Ag + MeCN 0.15 0.40 Fc + /Fc Calc Mn(tpfc) [55] 11 0.26 0.80 Fc + /Fc MeCN (0.1 M Bu 4 NClO 4 ) Mn(tpc) [55] Mn(10-(4-NO 2 Ph)-5,15-Ph)corrole Mn(10-Ph- 18 0.17 0.77 Fc + /Fc MeCN (0.1 M Bu 4 NClO 4 ) GC electrode Co(tpfc)(4-CNÀ Py) [73] 19 0.90 1.43 NHE MeCN (0.1 M Bu 4 NPF 6 ) 0.20 0.73 Fc + /Fc Calc Co(tpfc)Py [73] 19 0.84 1.42 NHE MeCN (0.1 M Bu 4 NPF 6 ) 0.14 0.72 Fc + /Fc Calc Co(tpfc)(4-NMe 2 -Py) [73] 19 0.82 1.39 NHE MeCN (0.1 M Bu 4 NPF 6 ) 0.12 0.69 Fc + /Fc Calc Co(tpfc)(4-OMEÀ Py) [73] 19 0.75 1.32 NHE MeCN (0.1 M Bu 4 NPF 6 ) 0.05 0.62 Fc + /Fc Calc Co(tpfc)(N-MeIm) [73] 19 0.73 1.41 NHE MeCN (0.1 M Bu 4 NPF 6 ) 0.03 0.71 Fc + /Fc Calc Co(tpfc)(PhS À ) [73] 19 0.73 1.10 NHE MeCN (0.1 M Bu 4 NPF 6 ) 0.03 0.40 Fc + /Fc Calc Co(L Br ) [74] 20 À 0.14 À 1.79 0.76 0.18 Fc + /Fc MeCN (0.1 M Bu 4 NPF 6 ) Co(L COOH ) [74] 20 À 0.52 À 1.83 0.76 0.17 Co(L PO(OEt)2 ) [74] 20 À 0.48 À 1.80 0.78 0.17 Co(L CH2PO(OEt)2 ) [74] 20 À 0. [75] 24 0.95 1.4 Ag/Ag + MeCN 0.55 1.0 Fc + /Fc Calc Fe(tpc)Cl [76] 25 0.16 1.09 Ag/Ag + 4 : 1 MeCNÀ PhCN (0.1 M Bu 4 NClO 4 ) À 0.24 0.69 Fc + /Fc Calc Fe(tdfc)Cl [76] 26 0.32 1.23 Ag/Ag + 4 : 1 MeCNÀ PhCN (0.1 M Bu 4 NClO 4 ) À 0.08 0.83 Fc + /Fc Calc Fe(tpfc)Cl [76] 27 0.47 1.33 Ag/Ag + 4 : 1 MeCNÀ PhCN (0.1 M Bu 4 NClO 4 ) 0.07 0.93 Fc + /Fc Calc (tpc)FeOFe(tpc) [76] 28 À 0.24 0.65 0.94 1.18 Ag/Ag + 4 : 1 MeCNÀ PhCN (0.1 M Bu 4 NClO 4 ) À 0.64 0.15 0.54 0.78 Fc + /Fc Calc (tdfc)FeOFe(tdfc) [76] 29 À 0.05 0.72 1.09 Ag/Ag + 4 : 1 MeCNÀ PhCN (0.1 M Bu 4 NClO 4 ) À 0.45 0.32 0.69 Fc + /Fc Calc (tpfc)FeOFe(tpfc) [76] 30 0.19 0.91 1.24 Ag/Ag + 4 : 1 MeCNÀ PhCN (0.1 M Bu 4 NClO 4 ) À 0.21 0.51 0.84 Fc...…”

Electrochemistry of Fe(IV) and Mn(IV) corroles containing meso-dichlorophenyl substituents and the use of these compounds as catalysts for the electroreduction of dioxygen in acid media

“…9−27 Our own research interests have long been focused on the synthesis and characterization of metallocorroles with an emphasis on cobalt, 16−19,28−33 iron, 34−36 and manganese derivatives. 37,38 In the present work, the synthesis, electrochemistry, and spectroelectrochemistry of iron(IV) and manganese(IV) meso-dichlorophenyl substituted metallocorroles are described. The examined compounds are represented as (Cl 2 Ph) 3 CorFeCl and (Cl 2 Ph) 3 CorMnCl, where (Cl 2 Ph) 3 Cor is the trianion of the 5,10,15-tri(2,4-dichlorophenyl)corrole.…”

“…9−27 Our own research interests have long been focused on the synthesis and characterization of metallocorroles with an emphasis on cobalt, 16−19,28−33 iron, 34−36 and manganese derivatives. 37,38 In the present work, the synthesis, electrochemistry, and spectroelectrochemistry of iron(IV) and manganese(IV) meso-dichlorophenyl substituted metallocorroles are described. The examined Metallocorroles with cobalt, 16,17,[19][20][21]24,25,39 iron, 20,26 and manganese 20 central metal ions are able to catalyze the electroreduction of oxygen via a 2e transfer process to produce H 2 O 2 or a 4e transfer process to generate H 2 O.…”