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Mikhail A. Vorotyntsev - One of the best experts on this subject based on the ideXlab platform.
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Electrochemical quartz crystal microbalance study of magnesium porphine electropolymerization process
Journal of Solid State Electrochemistry, 2020Co-Authors: O. I. Istakova, Dmitry V Konev, O. A. Goncharova, A. E. Antipov, C. H. Devillers, Mikhail A. VorotyntsevAbstract:Material and charge balances in the course of the electropolymerization process of the non-substituted Mg(II) porphine (MgP) at a low oxidation potential from its acetonitrile solutions of various concentrations have been studied via the in situ electrochemical quartz crystal microbalance method (EQCM). Thus, registered electrode mass increase due to the MgP oxidation at its surface has been used, in combination with in situ spectroelectrochemical data, for determination of the key parameters of the polymerization process and of the magnesium polyporphine films deposited on the electrode surface: current efficiency of the film deposition process, average charge spent for transformation of a Monomer Molecule into Monomer unit inside the film, number of Monomer units inside the deposited film, average number of valence bonds per one Monomer unit inside the film. Besides, the EQCM method applied to the discharge process of the electropolymerized film has allowed us to estimate the average charging (oxidation) degree of the Monomer unit inside the film at the polymerization potential and the degree of the solvent participation in the course of the polymer’s redox transitions. It has been established that the number of bonds between porphine units is within the range of 2.2 to 2.4, with its slight increase for films deposited at higher Monomer concentrations. Conclusions on the structure of polyporphine chains have been made.
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Electrochemical quartz crystal microbalance study of magnesium porphine electropolymerization process
Journal of Solid State Electrochemistry, 2020Co-Authors: O. I. Istakova, Dmitry V Konev, O. A. Goncharova, A. E. Antipov, C. H. Devillers, Mikhail A. VorotyntsevAbstract:Material and charge balances in the course of the electropolymerization process of the non-substituted Mg(II) porphine (MgP) at a low oxidation potential from its acetonitrile solutions of various concentrations have been studied via the in situ electrochemical quartz crystal microbalance method (EQCM). Thus, registered electrode mass increase due to the MgP oxidation at its surface has been used, in combination with in situ spectroelectrochemical data, for determination of the key parameters of the polymerization process and of the magnesium polyporphine films deposited on the electrode surface: current efficiency of the film deposition process, average charge spent for transformation of a Monomer Molecule into Monomer unit inside the film, number of Monomer units inside the deposited film, average number of valence bonds per one Monomer unit inside the film. Besides, the EQCM method applied to the discharge process of the electropolymerized film has allowed us to estimate the average charging (oxidation) degree of the Monomer unit inside the film at the polymerization potential and the degree of the solvent participation in the course of the polymer’s redox transitions. It has been established that the number of bonds between porphine units is within the range of 2.2 to 2.4, with its slight increase for films deposited at higher Monomer concentrations. Conclusions on the structure of polyporphine chains have been made.
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Spectroelectrochemical determination of the redox equivalent of magnesium porphine in the course of its electrooxidation
Doklady Physical Chemistry, 2016Co-Authors: O. I. Istakova, E. M. Antipov, Dmitry V Konev, Mikhail A. Vorotyntsev, Sergei M. AldoshinAbstract:The spectroelectrochemical method has been applied for studying the electropolymerization of magnesium porphine with the aim to determine the number of electrons consumed per Monomer Molecule, which allows one to find out the number of bonds between the units in the resulting polymer. Based on the results, a conclusion has been made about the structure of macrochains of the basic representative of a new family of electroactive materials, magnesium porphine
Kohtaro Osakada - One of the best experts on this subject based on the ideXlab platform.
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olefin polymerization catalyzed by double decker dipalladium complexes low branched poly α olefin s by selective insertion of the Monomer Molecule
Chemistry: A European Journal, 2015Co-Authors: Shigenaga Takano, Daisuke Takeuchi, Kohtaro OsakadaAbstract:Dipalladium complexes of a cyclic bis(diimine) ligand with a double-decker structure catalyze polymerization of ethylene and α-olefins and copolymerization of ethylene with 1-hexene. The polymerization of 1-hexene yields a polymer that is mainly composed of the hexamethylene unit formed by 2,1-insertion of the Monomer into the palladium-carbon bond, followed by chain-walking (6,1-insertion). The polymerization of 4-methyl-1-pentene proceeds by 2,1-insertion with a selectivity of 92-97 %, and affords the polymer with methyl and 2-methylhexyl branches. 2,1-Insertion occurs selectively in all of the polymerization reactions of α-olefins catalyzed by the dipalladium complexes. Ethylene polymerization with the catalyst at 100 °C lasts over 24 h, whereas the monopalladium-diimine catalyst loses its activity within 8 h at 60 °C. Polyethylene obtained by the dipalladium catalyst is less-branched and has a higher molecular weight compared to that of the monopalladium catalyst under the same conditions. Copolymerization of ethylene with 1-hexene affords solid products with melting points and molecular weights that vary depending on the polymerization time, suggesting formation of a block and/or gradient copolymer.
Liang Ding - One of the best experts on this subject based on the ideXlab platform.
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erratum to cyclodextrin based hyperbranched polymers by acyclic diene metathesis polymerization of an abn Monomer Molecule design synthesis and characterization
Journal of Polymer Research, 2012Co-Authors: Ning Wang, Liang DingAbstract:A novel cyclodextrin-based hyperbranched polymer (HBP) was synthetized via acyclic diene metathesis (ADMET) polymerization in homogeneous water/organic mixtures. A modified α-cyclodextrin (α-CD) Molecule with one electron-rich terminal alkene and many electron-poor acrylates was first prepared through the esterification reaction, and then utilized as an ABn-type Monomer for subsequent ADMET polymerization between alkene and acrylate using the second generation Hoveyda-Grubbs catalyst, yielding HBP with the reaction time prolonged. The chemical structures of Monomer and HBP were characterized by elemental analysis, IR, gel permeation chromatography with multiangle laser light scattering, and NMR measurements. The degree of branching was determined by using 1H NMR spectroscopy and the values ranged from 0.51 to 0.42. Influence of the molecular weight on the properties (thermal stability and solubility) was also investigated. The resulting HBPs showed the good thermal stability, and higher molecular weight resulted in higher decomposition temperature from 361 °C to 383 °C. These thermally stable HBPs also displayed the excellent solubility in aprotic polar solvents.
O. I. Istakova - One of the best experts on this subject based on the ideXlab platform.
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Electrochemical quartz crystal microbalance study of magnesium porphine electropolymerization process
Journal of Solid State Electrochemistry, 2020Co-Authors: O. I. Istakova, Dmitry V Konev, O. A. Goncharova, A. E. Antipov, C. H. Devillers, Mikhail A. VorotyntsevAbstract:Material and charge balances in the course of the electropolymerization process of the non-substituted Mg(II) porphine (MgP) at a low oxidation potential from its acetonitrile solutions of various concentrations have been studied via the in situ electrochemical quartz crystal microbalance method (EQCM). Thus, registered electrode mass increase due to the MgP oxidation at its surface has been used, in combination with in situ spectroelectrochemical data, for determination of the key parameters of the polymerization process and of the magnesium polyporphine films deposited on the electrode surface: current efficiency of the film deposition process, average charge spent for transformation of a Monomer Molecule into Monomer unit inside the film, number of Monomer units inside the deposited film, average number of valence bonds per one Monomer unit inside the film. Besides, the EQCM method applied to the discharge process of the electropolymerized film has allowed us to estimate the average charging (oxidation) degree of the Monomer unit inside the film at the polymerization potential and the degree of the solvent participation in the course of the polymer’s redox transitions. It has been established that the number of bonds between porphine units is within the range of 2.2 to 2.4, with its slight increase for films deposited at higher Monomer concentrations. Conclusions on the structure of polyporphine chains have been made.
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Electrochemical quartz crystal microbalance study of magnesium porphine electropolymerization process
Journal of Solid State Electrochemistry, 2020Co-Authors: O. I. Istakova, Dmitry V Konev, O. A. Goncharova, A. E. Antipov, C. H. Devillers, Mikhail A. VorotyntsevAbstract:Material and charge balances in the course of the electropolymerization process of the non-substituted Mg(II) porphine (MgP) at a low oxidation potential from its acetonitrile solutions of various concentrations have been studied via the in situ electrochemical quartz crystal microbalance method (EQCM). Thus, registered electrode mass increase due to the MgP oxidation at its surface has been used, in combination with in situ spectroelectrochemical data, for determination of the key parameters of the polymerization process and of the magnesium polyporphine films deposited on the electrode surface: current efficiency of the film deposition process, average charge spent for transformation of a Monomer Molecule into Monomer unit inside the film, number of Monomer units inside the deposited film, average number of valence bonds per one Monomer unit inside the film. Besides, the EQCM method applied to the discharge process of the electropolymerized film has allowed us to estimate the average charging (oxidation) degree of the Monomer unit inside the film at the polymerization potential and the degree of the solvent participation in the course of the polymer’s redox transitions. It has been established that the number of bonds between porphine units is within the range of 2.2 to 2.4, with its slight increase for films deposited at higher Monomer concentrations. Conclusions on the structure of polyporphine chains have been made.
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Spectroelectrochemical determination of the redox equivalent of magnesium porphine in the course of its electrooxidation
Doklady Physical Chemistry, 2016Co-Authors: O. I. Istakova, E. M. Antipov, Dmitry V Konev, Mikhail A. Vorotyntsev, Sergei M. AldoshinAbstract:The spectroelectrochemical method has been applied for studying the electropolymerization of magnesium porphine with the aim to determine the number of electrons consumed per Monomer Molecule, which allows one to find out the number of bonds between the units in the resulting polymer. Based on the results, a conclusion has been made about the structure of macrochains of the basic representative of a new family of electroactive materials, magnesium porphine
Jean-françois Dufrêche - One of the best experts on this subject based on the ideXlab platform.
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The role of curvature effects in liquid-liquid extraction: assessing organic phase mesoscopic properties from MD simulations.
Soft Matter, 2017Co-Authors: Magali Duvail, Steven Van Damme, Philippe Guilbaud, Yushu Chen, Thomas Zemb, Jean-françois DufrêcheAbstract:The bending rigidity of small reverse aggregates involved in liquid–liquid extraction processes has been investigated by molecular dynamics simulations. Simulations of a common extractant (DMDOHEMA) with four hydrophobic chains in explicit solvent (n-heptane) and in vacuum have been performed to determine the effect of solvent penetration on film stiffness. Elastic film bending energy that is needed for mesoscopic modelling of transfer of species between complex fluids is harmonic in terms of curvature (Helfrich formalism) and the packing parameter only if the solvent is explicitly taken into account. In terms of the packing parameter of the real molecular film constituting the reverse water in oil aggregates and taking into account molecular volume, area and film thickness (that is in agreement with Tanford's model), the bending rigidity is calculated to be about 16 kBT per extractant Molecule (about 40 kJ mol−1), which is smaller than the free energy of transfer from an isolated “Monomer” Molecule to a weak aggregate, but of the order of magnitude of the free energy of transfer used in liquid–liquid extraction processes.
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The role of curvature effects in liquid–liquid extraction: assessing organic phase mesoscopic properties from MD simulations
Soft Matter, 2017Co-Authors: Magali Duvail, Philippe Guilbaud, Yushu Chen, Thomas Zemb, Steven Van Damme, Jean-françois DufrêcheAbstract:The bending rigidity of small reverse aggregates involved in liquid–liquid extraction processes has been investigated by molecular dynamics simulations. Simulations of a common extractant (DMDOHEMA) with four hydrophobic chains in explicit solvent (n-heptane) and in vacuum have been performed to determine the effect of solvent penetration on film stiffness. Elastic film bending energy that is needed for mesoscopic modelling of transfer of species between complex fluids is harmonic in terms of curvature (Helfrich formalism) and the packing parameter only if the solvent is explicitly taken into account. In terms of the packing parameter of the real molecular film constituting the reverse water in oil aggregates and taking into account molecular volume, area and film thickness (that is in agreement with Tanford's model), the bending rigidity is calculated to be about 16 kBT per extractant Molecule (about 40 kJ mol−1), which is smaller than the free energy of transfer from an isolated “Monomer” Molecule to a weak aggregate, but of the order of magnitude of the free energy of transfer used in liquid–liquid extraction processes.