Cyclic voltammetry of nitronyl- and iminonitroxyls detected by electron spin resonance

Kadirov, Marsil K.; Tretyakov, Eugene V.; Budnikova, Yu. G.; Kholin, Kirill V.; Valitov, M. I.; Vavilova, V. N.; Овчаренко, В. И.; Sagdeev, R. Z.; Sinyashin, Оleg G.

doi:10.1134/s0036024409120280

Cited by 15 publications

(8 citation statements)

References 14 publications

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“…Along this VT process, the two manganese ions in their +II oxidation state at high temperature are oxidized to the +III oxidation state at low temperature and two of the three NITIm − radicals are reduced to the NITRed 2− aminoxyl and diamagnetic anion (Scheme 2). From electrochemistry experiments (Supporting Information) and in agreement with previous reports, 94 the E 1/2 redox potential aminoxyl anion/nitroxide radical is −0.25 V/SHE (standard hydrogen electrode), as shown in Figure S12, while the redox potential of the system Mn 3+ /Mn 2+ is given higher at 1.54 V/ SHE. This is in favor for stable Mn II -nitroxide complexes, as is generally observed.…”

Section: ■ Conclusionsupporting

confidence: 90%

Room Temperature Magnetic Switchability Assisted by Hysteretic Valence Tautomerism in a Layered Two-Dimensional Manganese-Radical Coordination Framework

et al. 2016

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The manganese-nitronyl-nitroxide two-dimensional coordination polymer {[Mn(NITIm)]ClO} (1) (NITImH = 2-(2-imidazolyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-3-oxide-1-oxyl) undergoes an unusual hysteretic thermo-induced valence tautomeric transition near room temperature, during which the manganese(II) ions are oxidized to manganese(III) and two of the three deprotonated radicals (NITIm) are reduced to their diamagnetic aminoxyl form (denoted NIT). Upon cooling, the high-temperature species {[Mn(NITIm)]ClO} (1) turns into the low-temperature species {[Mn(NIT)(NITIm)]ClO} (1) around 274 K, while on heating the process is reversed at about 287 K. This valence tautomeric phenomenon is supported by temperature-dependent magnetic susceptibility measurements, differential scanning calorimetry (DSC), crystal structure determination, UV-vis absorption, X-ray absorption (XAS), and emission (XES) and electron paramagnetic resonance (EPR) spectroscopies in the solid state.

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Section: ■ Conclusionsupporting

confidence: 90%

Room Temperature Magnetic Switchability Assisted by Hysteretic Valence Tautomerism in a Layered Two-Dimensional Manganese-Radical Coordination Framework

et al. 2016

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“…ESR proved to be an effective methodf or the exact magnetic resonance identification of free radicals [24,25] and transition metal ions in solutions, [26] for studies of classical micellar solutions of surfactants, [27] amphiphilic calix [4]arenes, [28] andf or intermediates of ESR electrochemical transformations. [29][30][31][32][33][34][35] In order to study the nature of the reduced forms of the catalytic complex the complex was studied using ESR during reduction by molecular hydrogen and the electrochemical reduction at the potential of the first peak. Figure 2D (Table 2).…”

Section: Resultsmentioning

confidence: 99%

Organometallic Polymer Electrolyte Membrane Fuel Cell Bis‐Ligand Nickel(Ii) Complex of 1,5‐Di‐P‐Tolyl‐3,7‐Dipyridine‐1,5,3,7‐Diazadiphosphacyclo‐Octane Catalyst

et al. 2018

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A 1,4‐Diaza‐3.7‐diphosphacyclo‐otane organometallic bis‐ligand nickel(II) complex [Ni(PPy2Np‐Tol2)2]2+2.[BF4]− on Vulcan XC‐72 (C) functions as both the cathode and anode catalysts in polymer electrolyte membrane fuel cell (PEMFC). In a PEMFC using Ni(Py‐p‐Tol)/C at the anode and Pt/C at the cathode the power density is shown to reach 14.66 mW cm−2, which is the highest power density of the none‐noble organometallic analogs. Based on the data produced using independent physico‐chemical methods, the mechanisms of the hydrogen oxidation and oxygen reduction reactions (HOR and ORR) on the anode and cathode sides of PEMFC, respectively, are reported.

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“…Electrochemical measurements were taken on a BASi Epsilon EClipse electrochemical analyzer (2701 Kent Avenue, West Lafayette, IN 47906, USA). A conventional three-electrode system [ 52 , 53 , 54 ] was used with glassy carbon as the working electrode, the Ag/AgCl (3 M KCl aqueous solution) electrode as the reference electrode, and a Pt wire as the counter electrode. The pH of solutions undergoing electrochemical studies was maintained with 0.1 M sodium phosphate buffer Na 2 HPO 4 /NaH 2 PO 4 (pH = 7).…”

Section: Methodsmentioning

confidence: 99%

A Water-Soluble Sodium Pectate Complex with Copper as an Electrochemical Catalyst for Carbon Dioxide Reduction

et al. 2021

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A selective noble-metal-free molecular catalyst has emerged as a fruitful approach in the quest for designing efficient and stable catalytic materials for CO2 reduction. In this work, we report that a sodium pectate complex of copper (PG-NaCu) proved to be highly active in the electrocatalytic conversion of CO2 to CH4 in water. Stability and selectivity of conversion of CO2 to CH4 as a product at a glassy carbon electrode were discovered. The copper complex PG-NaCu was synthesized and characterized by physicochemical methods. The electrochemical CO2 reduction reaction (CO2RR) proceeds at −1.5 V vs. Ag/AgCl at ~10 mA/cm2 current densities in the presence of the catalyst. The current density decreases by less than 20% within 12 h of electrolysis (the main decrease occurs in the first 3 h of electrolysis in the presence of CO2). This copper pectate complex (PG-NaCu) combines the advantages of heterogeneous and homogeneous catalysts, the stability of heterogeneous solid materials and the performance (high activity and selectivity) of molecular catalysts.

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Cyclic voltammetry of nitronyl- and iminonitroxyls detected by electron spin resonance

Cited by 15 publications

References 14 publications

Room Temperature Magnetic Switchability Assisted by Hysteretic Valence Tautomerism in a Layered Two-Dimensional Manganese-Radical Coordination Framework

Room Temperature Magnetic Switchability Assisted by Hysteretic Valence Tautomerism in a Layered Two-Dimensional Manganese-Radical Coordination Framework

Organometallic Polymer Electrolyte Membrane Fuel Cell Bis‐Ligand Nickel(Ii) Complex of 1,5‐Di‐P‐Tolyl‐3,7‐Dipyridine‐1,5,3,7‐Diazadiphosphacyclo‐Octane Catalyst

A Water-Soluble Sodium Pectate Complex with Copper as an Electrochemical Catalyst for Carbon Dioxide Reduction

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