27 results on '"Budnikova YH"'
Search Results
2. Cobalt(II) coordination to an N 4 -acenaphthene-based ligand and its sodium complex.
- Author
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Khrizanforova VV, Fayzullin RR, Bogomyakov AS, Morozov VI, Batulin RG, Gerasimova TP, Islamov DR, and Budnikova YH
- Abstract
A new bifunctional N
4 -ligand was obtained via the condensation reaction of acenaphthenequinone and 2-picolylamine. A peculiarity of this synthesis is the formation of a new intramolecular C-C bond during the reaction. The structure and redox properties of the ligand were studied. The anion-radical form of the ligand was prepared via the chemical reduction of the latter with metallic sodium as well as in situ via its electrochemical reduction in a solution. The sodium salt prepared was structurally characterized using single-crystal X-ray diffraction (XRD). New cobalt complexes with the ligand in neutral and anion-radical forms were synthesized and further studied. As a result, three new homo- and heteroleptic cobalt(II) complexes were obtained, in which the cobalt atom demonstrates different modes of coordination with the ligand. Cobalt(II) complex CoL2 with two monoanionic ligands was prepared by the electrochemical reduction of a related L2 CoBr2 complex or by treating cobalt(II) bromide with the sodium salt. XRD was used to study the structures of all cobalt complexes prepared. Magnetic and electron paramagnetic resonance studies were performed: CoII ion states with S = 3/2 and S = 1/2 were found for the complexes. A quantum-chemical study confirmed that the spin density is mainly located at the cobalt center.- Published
- 2023
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3. Chemical and Electrochemical Reductions of Monoiminoacenaphthenes.
- Author
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Khrizanforova VV, Fayzullin RR, Gerasimova TP, Khrizanforov MN, Zagidullin AA, Islamov DR, Lukoyanov AN, and Budnikova YH
- Subjects
- Oxidation-Reduction, Anions chemistry, Cations chemistry, Sodium
- Abstract
Redox properties of monoiminoacenaphthenes (MIANs) were studied using various electrochemical techniques. The potential values obtained were used for calculating the electrochemical gap value and corresponding frontier orbital difference energy. The first-peak-potential reduction of the MIANs was performed. As a result of controlled potential electrolysis, two-electron one-proton addition products were obtained. Additionally, the MIANs were exposed to one-electron chemical reduction by sodium and NaBH
4 . Structures of three new sodium complexes, three products of electrochemical reduction, and one product of the reduction by NaBH4 were studied using single-crystal X-ray diffraction. The MIANs reduced electrochemically by NaBH4 represent salts, in which the protonated MIAN skeleton acts as an anion and Bu4 N+ or Na+ as a cation. In the case of sodium complexes, the anion radicals of MIANs are coordinated with sodium cations into tetranuclear complexes. The photophysical and electrochemical properties of all reduced MIAN products, as well as neutral forms, were studied both experimentally and quantum-chemically.- Published
- 2023
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4. Non-Noble-Metal Mono and Bimetallic Composites for Efficient Electrocatalysis of Phosphine Oxide and Acetylene C-H/P-H Coupling under Mild Conditions.
- Author
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Tarasov MV, Bochkova OD, Gryaznova TV, Mustafina AR, and Budnikova YH
- Subjects
- Metals chemistry, Alkynes, Oxides, Nanoparticles
- Abstract
The present work describes an efficient reaction of electrochemical phosphorylation of phenylacetylene controlled by the composition of catalytic nanoparticles based on non-noble-metals. The sought-after products are produced via the simple synthetic protocol based on room temperature, atom-economical reactions, and silica nanoparticles (SNs) loaded by one or two d-metal ions as nanocatalysts. The redox and catalytic properties of SNs can be tuned with a range of parameters, such as compositions of the bimetallic systems, their preparation method, and morphology. Monometallic SNs give phosphorylated acetylene with retention of the triple bond, and bimetallic SNs give a bis-phosphorylation product. This is the first example of acetylene and phosphine oxide C-H/P-H coupling with a regenerable and recyclable catalyst.
- Published
- 2023
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5. Recent advances in electrochemical C-H phosphorylation.
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Budnikova YH, Dolengovsky EL, Tarasov MV, and Gryaznova TV
- Abstract
The activation of C-H bond, and its direct one-step functionalization, is one of the key synthetic methodologies that provides direct access to a variety of practically significant compounds. Particular attention is focused on modifications obtained at the final stages of the synthesis of complicated molecules, which requires high tolerance to the presence of existing functional groups. Phosphorus is an indispensable element of life, and phosphorus chemistry is now experiencing a renaissance due to new emerging applications in medicinal chemistry, materials chemistry (polymers, flame retardants, organic electronics, and photonics), agricultural chemistry (herbicides, insecticides), catalysis (ligands) and other important areas of science and technology. In this regard, the search for new, more selective, low-waste synthetic routes become relevant. In this context, electrosynthesis has proven to be an eco-efficient and convenient approach in many respects, where the reagents are replaced by electrodes, where the reactants are replaced by electrodes, and the applied potential the applied potential determines their "oxidizing or reducing ability". An electrochemical approach to such processes is being developed rapidly and demonstrates some advantages over traditional classical methods of C-H phosphorylation. The main reasons for success are the exclusion of excess reagents from the reaction system: such as oxidants, reducing agents, and sometimes metal and/or other improvers, which challenge isolation, increase the wastes and reduce the yield due to frequent incompatibility with these functional groups. Ideal conditions include electron as a reactant (regulated by applied potential) and the by-products as hydrogen or hydrocarbon. The review summarizes and analyzes the achievements of electrochemical methods for the preparation of various phosphorus derivatives with carbon-phosphorus bonds, and collects data on the redox properties of the most commonly used phosphorus precursors. Electrochemically induced reactions both with and without catalyst metals, where competitive oxidation of precursors leads to either the activation of C-H bond or to the generation of phosphorus-centered radicals (radical cations) or metal high oxidation states will be examined. The review focuses on publications from the past 5 years., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Budnikova, Dolengovsky, Tarasov and Gryaznova.)
- Published
- 2022
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6. Composing NLO Chromophore as a Puzzle: Electrochemistry-based Approach to Design and Effectiveness.
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Dudkina YB, Kalinin AA, Fazleeva GM, Sharipova SM, Islamova LN, Dobrynin AB, Islamov DR, Levitskaya AI, Balakina MY, and Budnikova YH
- Abstract
A series of D-π-A, D-π-D'-π-A, D-π-A'-π-A nonlinear optical chromophores with vinylene π-electron bridges or bridges with π-deficient/π-excessive heterocyclic moieties along with the corresponding precursors D-vinylene, D-π-D', D'-π-A, D-π-A' and A'-π-A are synthesized and studied both experimentally and computationally. The effect of the heterocycle in the π-electron bridge on the oxidation/reduction potentials and the energy gap (ΔE
el ) is investigated in detail. The properties of the D-π-A'(D')-π-A chromophores are shown to correlate with those of building blocks: the oxidation potential is determined by the D-vinylene, and the reduction potential is determined by A'(D')-π-A truncated compounds. The contribution of the acceptor to the oxidation potential of chromophores in comparison with those of the precursors was estimated and analyzed in terms of electronic communication between the end groups. A good correlation between the ΔEel and the chromophores' first hyperpolarizability is revealed., (© 2021 Wiley-VCH GmbH.)- Published
- 2021
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7. Synthesis of fullerenyl-1,2,3-triazoles by reaction of fullerenyl azide with terminal acetylenes.
- Author
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Sadretdinova ZR, Akhmetov AR, Tulyabaev AR, Budnikova YH, Dudkina YB, Tuktarov AR, and Dzhemilev UM
- Abstract
Fullerenyltriazoles were synthesized by the interaction of azidofullerene with terminal acetylenes, in which the heterocyclic fragment is directly attached to the fullerene core. The electrochemical studies of the synthesized triazole-containing fullerenes have proved that the potentials of the first reduction peaks are shifted to a less cathodic region compared to unmodified C
60 . According to theoretical calculations, synthesized fullerene C60 derivatives can be considered as promising acceptor components of organic solar cells.- Published
- 2021
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8. A Water-Soluble Sodium Pectate Complex with Copper as an Electrochemical Catalyst for Carbon Dioxide Reduction.
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Kholin KV, Khrizanforov MN, Babaev VM, Nizameeva GR, Minzanova ST, Kadirov MK, and Budnikova YH
- Abstract
A selective noble-metal-free molecular catalyst has emerged as a fruitful approach in the quest for designing efficient and stable catalytic materials for CO
2 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 (CO2 RR) 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.- Published
- 2021
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9. Electrochemical Insight into Mechanisms and Metallocyclic Intermediates of C-H Functionalization.
- Author
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Budnikova YH
- Abstract
Transition metal-catalyzed C-H activation has emerged as a powerful tool in organic synthesis and electrosynthesis as well as in the development of new methodologies for producing fine chemicals. In order to achieve efficient and selective C-H functionalization, different strategies have been used to accelerate the C-H activation step, including the incorporation of directing groups in the substrate that facilitate coordination to the catalyst. In this review, we try to underscore that the understanding the mechanisms of the catalytic cycle and the reactivity or redox activity of the key metal cyclic intermediates in these reactions is the basis for controlling the selectivity of synthesis and electrosynthesis. Combination of the electrosynthesis and voltammetry with traditional synthetic and physico-chemical methods allows one to achieve selective transformation of C-H bonds to functionalized C-C or C-X (X=heteroatom or halogen) bonds which may encourage organic chemists to use it in the future more often. The possibilities and the benefits of electrochemical techniques are analyzed and summarized., (© 2021 The Chemical Society of Japan & Wiley-VCH GmbH.)
- Published
- 2021
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10. Synthesis, structure, and electrochemical properties of 4,5-diaryl-1,2,3-triphosphaferrocenes and the first example of multi(phosphaferrocene).
- Author
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Petrov AV, Zagidullin AA, Bezkishko IA, Khrizanforov MN, Kholin KV, Gerasimova TP, Ivshin KA, Shekurov RP, Katsyuba SA, Kataeva ON, Budnikova YH, and Miluykov VA
- Abstract
The reaction between aryl substituted sodium 1,2,3-triphospholides or disodium bis(1,2,3-triphospholide) and [Fe(η6-(C6H5CH3)Cp]+[PF6]- in boiling diglyme results in pure 1,2,3-triphosphaferrocenes 1-3 or bis(1,2,3-triphosphaferrocene) 4, respectively, in good yields. The structure of all obtained 1,2,3-triphosphaferrocenes 1-4 has been extensively studied experimentally (NMR, UV-Vis spectroscopy, and X-ray analysis for 1 and 4) and quantum chemically. The electrochemical properties of 1,2,3-triphosphaferrocenes 1-4 in the solid state were studied for the first time and a reversible one-electron oxidation (E1/2 = 0.52-0.92 V vs. Fc+/Fc) was demonstrated for 1, 3, and 4. In the case of 1,4-bis(5-phenyl-4-(1,2,3-triphospaferrocenyl))benzene 4, consecutive oxidation in the solid state is observed in contrast to other 1,2,3-triphosphaferrocenes 1-3. According to the ESR data, the g-factor of the oxidized bis(1,2,3-triphosphaferrocene), 4 (g = 2.12) is different from the g-factors of oxidized 1,2,3-triphosphaferrocenes 1-3 (g = 2.01). This is the first example of multi(ferrocenyl) systems based on the phosphaferrocene motif, which in turn opens up a new fundamental platform for the preparation of compounds with stimuli-responsive properties.
- Published
- 2020
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11. Recent advances in metal-organic frameworks for electrocatalytic hydrogen evolution and overall water splitting reactions.
- Author
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Budnikova YH
- Abstract
Rational design and synthesis of efficient metal-organic frameworks (MOFs) as electrode modifiers for energy-related electrocatalytic applications are crucial for the development of clean-energy technologies. The present review focuses on recent work on robust earth-abundant heterogeneous catalysts based on pristine MOFs for the hydrogen evolution reaction (HER) and overall water splitting. These catalysts have been extensively studied as alternatives for noble metal-based ones, demonstrating "hydrogen economy" development prospects. In addition, novel strategies to enhance the conductivity, chemical stability and efficiency of MOF-based electrocatalysts are discussed. The best electrocatalysts even surpass the achievements of the platinum group of metals and MOF-derived catalysts in catalytic performance. The electrolytic cells with MOF-modified electrodes demonstrated excellent catalytic activity and can deliver a high current density at a voltage lower than that using the precious metal-based Pt/C cathodes and IrO2 anodes. In this review article, current approaches to design such MOF and MOF-modified electrode materials are summarized and analyzed.
- Published
- 2020
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12. Synthesis and Electrochemical Properties of Fullerenylstyrenes.
- Author
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Tuktarov AR, Chobanov NM, Budnikova YH, Dudkina YB, and Dzhemilev UM
- Abstract
An efficient preparative method was developed for the synthesis of previously unreported fullerenylstyrenes based on the reaction of C
60 fullerene with terminal acetylenes and EtMgBr in the presence of Ti(O i -Pr)4 . The voltammetric curves of the prepared fullerenylstyrenes were studied, and good prospects for their application as acceptor materials for bulk heterojunction solar cell were demonstrated.- Published
- 2019
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13. One-Electron Reduction of Acenaphthene-1,2-Diimine Nickel(II) Complexes.
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Khrizanforova VV, Fayzullin RR, Morozov VI, Gilmutdinov IF, Lukoyanov AN, Kataeva ON, Gerasimova TP, Katsyuba SA, Fedushkin IL, Lyssenko KA, and Budnikova YH
- Abstract
New nickel-based complexes of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with BF
4 - counterion or halide co-ligands were synthesized in THF and MeCN. The nickel(I) complexes were obtained by using two approaches: 1) electrochemical reduction of the corresponding nickel(II) precursors; and 2) a chemical comproportionation reaction. The structural features and redox properties of these complexes were investigated by using single-crystal X-ray diffraction (XRD), cyclic voltammetry (CV), and electron paramagnetic resonance (EPR) and UV/Vis spectroscopy. The influence of temperature and solvent on the structure of the nickel(I) complexes was studied in detail, and an uncommon reversible solvent-induced monomer/dimer transformation was observed. In the case of the fluoride complex, the unpaired electron was found to be localized on the dpp-bian ligand, whereas all of the other nickel complexes contained neutral dpp-bian moieties., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2019
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14. Nano-architecture of silica nanoparticles as a tool to tune both electrochemical and catalytic behavior of Ni II @SiO 2 .
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Khrizanforov MN, Fedorenko SV, Mustafina AR, Khrizanforova VV, Kholin KV, Nizameev IR, Gryaznova TV, Grinenko VV, and Budnikova YH
- Abstract
The present work introduces a facile synthetic route for efficient doping of [Ni
II (bpy)x ] into silica nanoparticles with various sizes and architectures. Variation of the latter results in different concentrations of the NiII complexes at the interface of the composite nanoparticles. The UV-Vis analysis of the nanoparticles reveals changes in the inner-sphere environment of the NiII complexes when embedded into the nanoparticles, while the inner-sphere of NiII is invariant for the nanoparticles with different architecture. Comparative analysis of the electrochemically generated redox transformations of the NiII complexes embedded in the nanoparticles of various architectures reveals the latter as the main factor controlling the accessibility of NiII complexes to the redox transitions which, in turn, controls the electrochemical behavior of the nanoparticles. The work also highlights an impact of the nanoparticulate architecture in catalytic activity of the NiII complexes within the different nanoparticles in oxidative C-H fluoroalkylation of caffeine. Both low leakage and high concentration of the NiII complexes at the interface of the composite nanoparticles enables fluoroalkylated caffeine to be obtained in high yields under recycling of the nanocatalyst five times at least., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2019
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15. One-Electron Reduction of 2-Mono(2,6-diisopropylphenylimino)acenaphthene-1-one (dpp-mian).
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Lukoyanov AN, Ulivanova EA, Razborov DA, Khrizanforova VV, Budnikova YH, Makarov SG, Rumyantcev RV, Ketkov SY, and Fedushkin IL
- Abstract
The electrochemical characteristics of 2-mono(2,6-diisopropylphenylimino)acenaphthene-1-one (dpp-mian) have been investigated. One-electron reduction of dpp-mian involves the iminoketone fragment, which is revealed by the EPR spectrum obtained after the electrolysis of the dpp-mian solution in tetrahydrofuran (THF). The reduction of dpp-mian with one equivalent of metallic potassium leads to a similar EPR spectrum. The sodium complex [(dpp-mian)Na(dme)]
2 (1) produces an EPR signal with hyperfine coupling on the nitrogen atom of the iminoketone fragment of the dpp-mian ligand. Dpp-mian can also be reduced in a one-electron process by SnCl2 ×(dioxane). In this case, complex (dpp-mian)2 SnCl2 (2) is formed, with the tin atom displaying an oxidation state of +4. Tin(II) chloride dihydrate, SnCl2 ×2(H2 O), also reduces dpp-mian, but the two ligands bound to tin in the product form a new carbon-carbon bond between the ketone moieties of the dpp-mian monoanions to form complex (bis-dpp-mian)HSnCl3 (3). Metallic tin reduces dpp-mian to form the (bis-dpp-mian)2 Sn (4) species. Compounds 1-4 were characterized by X-ray diffraction., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2019
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16. Deprotonation of Benzoxazolium Salt: Trapping of a Radical-Cation Intermediate.
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Klementyeva SV, Abramov PA, Somov NV, Dudkina YB, Budnikova YH, and Poddel'sky AI
- Abstract
The deprotonation of N-2,6-diisopropylphenyl-substituted benzoxazolium tetrafluoroborate 1 with NaH results in the formation of electron-rich diaminodioxaethylene 2. The radical cation salt 2
·+ ·BF4 - is found to be an intermediate product in the redox reaction leading from 1 to 2.- Published
- 2019
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17. Silica-supported silver nanoparticles as an efficient catalyst for aromatic C-H alkylation and fluoroalkylation.
- Author
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Khrizanforov MN, Fedorenko SV, Mustafina AR, Kholin KV, Nizameev IR, Strekalova SO, Grinenko VV, Gryaznova TV, Zairov RR, Mazzaro R, Morandi V, Vomiero A, and Budnikova YH
- Abstract
The efficient catalysis of oxidative alkylation and fluoroalkylation of aromatic C-H bonds is of paramount importance in the pharmaceutical and agrochemical industries, and requires the development of convenient Ag0-based nano-architectures with high catalytic activity and recyclability. We prepared Ag-doped silica nanoparticles (Ag0/+@SiO2) with a specific nano-architecture, where ultra-small sized silver cores are immersed in silica spheres, 40 nm in size. The nano-architecture provides an efficient electrochemical oxidation of Ag+@SiO2 without any external oxidant. In turn, Ag+@SiO2 5 mol% results in 100% conversion of arenes into their alkylated and fluoroalkylated derivatives in a single step at room temperature under nanoheterogeneous electrochemical conditions. Negligible oxidative leaching of silver from Ag0/+@SiO2 is recorded during the catalytic coupling of arenes with acetic, difluoroacetic and trifluoroacetic acids, which enables the good recyclability of the catalytic function of the Ag0/+@SiO2 nanostructure. The catalyst can be easily separated from the reaction mixture and reused a minimum of five times upon electrochemical regeneration. The use of the developed Ag0@SiO2 nano-architecture as a heterogeneous catalyst facilitates aromatic C-H bond substitution by alkyl and fluoroalkyl groups, which are privileged structural motifs in pharmaceuticals and agrochemicals.
- Published
- 2018
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18. External oxidant-free cross-coupling: electrochemically induced aromatic C-H phosphonation of azoles with dialkyl-H-phosphonates under silver catalysis.
- Author
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Yurko EO, Gryaznova TV, Kholin KV, Khrizanforova VV, and Budnikova YH
- Abstract
A convenient external oxidant-free method of phosphorylation of azole derivatives (benzo-1,3-azoles, 3-methylindole, 4-methyl-2-acetylthiazole) by using dialkyl-H-phosphonates through the catalytic oxidation of their mixture under electrochemical mild conditions (room temperature, normal pressure) in the presence of silver salts or oxide (1%) is proposed. This method allows us to obtain the desired azole dialkylphosphonates with good yield (up to 75%). The transformations of silver and phosphorus precursors and intermediates using cyclic voltammetry, ESR, and NMR spectroscopy were investigated, and a radical process mechanism was proposed. It has been found that AgP(O)(OEt)
2 is oxidized earlier than other components of the reaction mixture with the elimination of a radical. The ESR spectrum of this radical's adduct was obtained in the presence of the radical trap PBN. Ag2+ is out of the catalytic cycle.- Published
- 2017
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19. Redox trends in cyclometalated palladium(ii) complexes.
- Author
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Dudkina YB, Kholin KV, Gryaznova TV, Islamov DR, Kataeva ON, Rizvanov IK, Levitskaya AI, Fominykh OD, Balakina MY, Sinyashin OG, and Budnikova YH
- Abstract
A series of diverse binuclear and mononuclear cyclometalated palladium(ii) complexes of different structure was investigated by electrochemical techniques combined with density functional theory (DFT) calculations. The studies including cyclic and differential pulse voltammetry, X-ray structure analysis and quantum chemical calculations revealed a regularity of the complexes oxidation potential on the metal-metal distance in the complexes: the larger Pd-Pd distance, the higher oxidation potentials. The reduction potentials feature unusually high negative values while no correlation depending on the structure could be observed. These results are in a good agreement with the electron density distribution in the complexes. Additionally, ESR data obtained for the complexes upon oxidation is reported.
- Published
- 2016
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20. Oxygen reduction reaction catalyzed by nickel complexes based on thiophosphorylated calix[4]resorcinols and immobilized in the membrane electrode assembly of fuel cells.
- Author
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Kadirov MK, Knyazeva IR, Nizameev IR, Safiullin RA, Matveeva VI, Kholin KV, Khrizanforova VV, Ismaev TI, Burilov AR, Budnikova YH, and Sinyashin OG
- Abstract
The catalytic activity of the nickel complexes of thiophosphorylated calix[4]resorcinols for oxygen reduction in a polymer electrolyte membrane fuel cell (PEMFC) has been studied. The conformation of the macrocyclic ligand determines the morphology and catalytic properties of the resulting organometallic species.
- Published
- 2016
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21. A Ni(iii) complex stabilized by silica nanoparticles as an efficient nanoheterogeneous catalyst for oxidative C-H fluoroalkylation.
- Author
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Khrizanforov MN, Fedorenko SV, Strekalova SO, Kholin KV, Mustafina AR, Zhilkin MY, Khrizanforova VV, Osin YN, Salnikov VV, Gryaznova TV, and Budnikova YH
- Abstract
We have developed Ni(III)-doped silica nanoparticles ([(bpy)xNi(III)]@SiO2) as a recyclable, low-leaching, and efficient oxidative functionalization nanocatalyst for aromatic C-H bonds. The catalyst is obtained by doping the complex [(bpy)3Ni(II)] on silica nanoparticles along with its subsequent electrooxidation to [(bpy)xNi(III)] without an additional oxidant. The coupling reaction of arenes with perfluoroheptanoic acid occurs with 100% conversion of reactants in a single step at room temperature under nanoheterogeneous conditions. The catalyst content is only 1% with respect to the substrates under electrochemical regeneration conditions. The catalyst can be easily separated from the reaction mixture and reused a minimum of five times. The results emphasize immobilization on the silica support and the electrochemical regeneration of Ni(III) complexes as a facile route for developing an efficient nanocatalyst for oxidative functionalization.
- Published
- 2016
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22. New sterically-hindered o-quinones annelated with metal-dithiolates: regiospecificity in oxidative addition reactions of a bifacial ligand to the Pd and Pt complexes.
- Author
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Martyanov KA, Cherkasov VK, Abakumov GA, Samsonov MA, Khrizanforova VV, Budnikova YH, and Kuropatov VA
- Abstract
An unusual reactivity of sterically hindered o-quinones with an annelated dithiete ring towards coordination at a dithiolene site has been discovered. New Pd and Pt dithiolate complexes have been synthesized. The reaction proceeds regioselectively, and the quinone site of the parent ligand is not affected even while using an excess of the metal complex. Both Pt and Pd complexes display a square planar surrounding for the metal ion and have very similar NMR, IR and UV/Vis spectra. Surprisingly, being coordinated at the dithiolene site to the metal, the ligand exhibits activity like an o-quinone, it could be reduced with different metals resulting in the corresponding o-semiquinonates which were confirmed by EPR spectroscopy. It was shown that an unpaired electron exhibits HFC with the phosphorus nuclei of phosphine ligands coordinated to the metal ions at the dithiolene site of the molecule.
- Published
- 2016
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23. Accessing perfluoroalkyl nickel(II), (III), and (IV) complexes bearing a readily attached [C4F8] ligand.
- Author
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Yu S, Dudkina Y, Wang H, Kholin KV, Kadirov MK, Budnikova YH, and Vicic DA
- Abstract
The [C4F8] ligand was shown to support well-defined terpyridyl nickel complexes in the +2 and +3 oxidation states. Notably, a cyclic voltammetry study of the nickel(iii) species indicates that an additional oxidation is accessible, providing a family of related fluoroalkyl nickel complexes spanning the +2 to +4 oxidation states.
- Published
- 2015
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24. Nanoheterogeneous catalysis in electrochemically induced olefin perfluoroalkylation.
- Author
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Dudkina YB, Gryaznova TV, Osin YN, Salnikov VV, Davydov NA, Fedorenko SV, Mustafina AR, Vicic DA, Sinyashin OG, and Budnikova YH
- Abstract
Ni-catalyzed electroreductive olefin perfluoroalkylation affords both monomeric and dimeric products depending on the reaction media. Recycling of the catalyst can be achieved by immobilization of a (bpy)NiBr2 complex on silica nanoparticles decorated with anchoring amino-groups. Switching the homogeneous and heterogeneous catalysts is found to be one more factor to control the product ratio. This catalytic technique is both green and atom economical and combines the advantages of nanoheterogeneous catalysis and electrocatalysis.
- Published
- 2015
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25. Synthesis and reactivity of new aminophenolate complexes of nickel.
- Author
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Yu S, Wang H, Sledziewski JE, Madhira VN, Takahashi CG, Leon MK, Dudkina YB, Budnikova YH, and Vicic DA
- Subjects
- Crystallography, X-Ray, Models, Molecular, Molecular Conformation, Aminophenols chemical synthesis, Coordination Complexes chemical synthesis, Nickel chemistry
- Abstract
New well-defined, paramagnetic nickel complexes have been prepared and characterized by X-ray crystallography. The complexes were found to be active for the cross-coupling of alkyl electrophiles (especially ethyl 2-bromobutyrate) with alkyl Grignard reagents. The ligand architecture in these new complexes could potentially be rendered chiral, opening up future possibilities for performing asymmetric cross-coupling reactions.
- Published
- 2014
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26. New functional cyclic aminomethylphosphine ligands for the construction of catalysts for electrochemical hydrogen transformations.
- Author
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Musina EI, Khrizanforova VV, Strelnik ID, Valitov MI, Spiridonova YS, Krivolapov DB, Litvinov IA, Kadirov MK, Lönnecke P, Hey-Hawkins E, Budnikova YH, Karasik AA, and Sinyashin OG
- Abstract
Eight-membered cyclic functional bisphosphines, namely 1,5-di-aryl-3,7-di(2-pyridyl)-1,5-diaza-3,7-diphosphacyclooctanes (aryl=2-pyridyl, m-tolyl, p-tolyl, diphenylmethyl, benzyl, (R)-(+)-(α-methyl)benzyl), with 2-pyridyl substituents on the phosphorus atoms have been synthesized by condensation of 2-pyridylphosphine, formaldehyde, and the corresponding primary amine. The structures of some of these bisphosphines have been investigated by X-ray crystallography. The bisphosphines readily form neutral P,P-chelate complexes [(κ(2)-P,P-L)MCl2], cationic bis-P,P-chelate complexes [(κ(2)-P,P-L)2 M](2+), or a five-coordinate complex [(κ(2)-P,P-L)2 NiBr]Br. The electrochemical behavior of two of the nickel complexes, and their catalytic activities in electrochemical hydrogen evolution and hydrogen oxidation, including the fuel-cell test, have been studied., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2014
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27. Redox trends in terpyridine nickel complexes.
- Author
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Ciszewski JT, Mikhaylov DY, Holin KV, Kadirov MK, Budnikova YH, Sinyashin O, and Vicic DA
- Subjects
- Crystallography, X-Ray, Models, Molecular, Molecular Structure, Oxidation-Reduction, Stereoisomerism, Nickel chemistry, Organometallic Compounds chemistry, Pyridines chemistry
- Abstract
A synthesis has been developed that allows the isolation of four-coordinate [(tpy)Ni-Br] (1, tpy = terpyridine) in high yield. Complex 1 has been structurally characterized, and the X-ray data reveal a square-planar geometry, unlike the known [(tpy')Ni-I] (tpy' = 4,4',4''-tri-tert-butyl-terpyridine) but similar to [(tpy)Ni-CH(3)]. In the solid-state, EPR spectroscopy indicates, however, that unlike [(tpy)Ni-CH(3)], the electronic structure of 1 is a metal-centered, not a ligand-centered radical. Density functional theory (DFT) analyses support this assignment. The preparation of 1 also facilitated the analysis of the redox potentials of a series of terpyridine nickel derivatives. It was found that the overall ligand sphere (one vs two coordinated terpyridine ligands) plays more of a role in determining the redox potentials of these derivatives than do the formal oxidation states of the nickel ions in the solution phase.
- Published
- 2011
- Full Text
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