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Your search keyword '"Ivakhnenko, E. P."' showing total 157 results
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157 results on '"Ivakhnenko, E. P."'

8. 12H-Quinoxalino[2,3-b]phenoxazinium complexes with CoII and ZnII hexafluoroacetylacetonates: synthesis, structure, and properties.

Author

Minkin, V. I., Aldoshin, S. M., Omelichkin, N. I., Shilov, G. V., Korchagin, D. V., Kunitsyna, E. I., Makarova, N. I., Starikov, A. G., Borodkin, G. S., Knyazev, P. A., and Ivakhnenko, E. P.

Subjects
SUPERCONDUCTING quantum interference devices, MAGNETIC properties, NUCLEAR magnetic resonance spectroscopy, PROTON transfer reactions, TAUTOMERISM, X-ray diffraction
Abstract

Reactions of 12H-quinoxaline[2,3-b]phenoxazine (QOPO) derivatives with the CoII and ZnII hexafluoroacetylacetonates accompanied by protonation of the starting bases result in stable complexes [QOPOH]+[M(hfac)3]− whose structure was determined by X-ray diffraction and by 1H and 15N NMR spectroscopy. The complexes are characterized by long-wavelength absorption (560–664 nm) and fluorescence in the red region (λfl = 674–805 nm). The relative energies of the protonated tautomers N(14)—H and N(7)—H were determined using the results of B3LYP–D3BJ/6-311G++(d,p) density functional calculations with inclusion of D3BJ dispersion correction. A SQUID magnetometry study of the static and dynamic magnetic properties of the CoII complex revealed that it behaves as a field-induced single-ion magnet. [ABSTRACT FROM AUTHOR]

Published
2024
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11. Field-assisted slow relaxation of magnetization in Cu(II) complexes with pentaheterocyclic triphenodioxazine ligands: the quasi-one-dimensional versus the binuclear case.

Author

Korchagin, D. V., Ivakhnenko, E. P., Demidov, O. P., Knyazev, P. A., Efimov, N. N., Morgunov, R. B., Starikov, A. G., Palii, A. V., Minkin, V. I., and Aldoshin, S. M.

Subjects
*COPPER, *QUANTUM tunneling, *MAGNETIC relaxation, *MAGNETIZATION, *LIGANDS (Chemistry), *COORDINATION polymers, *COPPER ions, *RAMAN scattering
Abstract

Two new copper(II) complexes have been obtained by the reaction of sterically crowded triphenodioxazine ligands with Cu(II) hexafluoroacetylacetonate. Compound 1 is a co-crystal of Cu(hfac)2 moieties and triphenodioxazine molecules within a quasi-one-dimensional crystal structure with only weak Cu⋯N short intermolecular interactions (Cu⋯N distances are equal to 2.69(1) and 2.75(1) Å). In contrast, complex 2 has a binuclear structure with two Cu(hfac)2 units bridged through triphenodioxazine ligand with the covalent Cu–N bond length of 2.335(2) Å. The magnetic AC susceptibility data show that in spite of the absence of zero-field splitting in the Cu(II) ion having the ground state with spin S = 1/2, both compounds demonstrate slow magnetic relaxation at the applied magnetic field. For a quasi-one-dimensional complex 1, the optimal field for observing slow magnetic relaxation is 400 Oe, while for the binuclear complex it is 2500 Oe. The observed temperature dependence of the relaxation time in 1 is well described by the combination of Raman and direct mechanisms of relaxation, while for complex 2 the inclusion of Raman mechanism and quantum tunneling of magnetization is required to describe the relaxation behavior. [ABSTRACT FROM AUTHOR]

Published
2023
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47. Synthesis, chemical properties, and crystal structure of 2,4,6,8-tetra( tert-butyl)-9-hydroxyphenoxazin-1-one.

Author

Simakov, V. I., Gorbanev, Yu. Yu., Ivakhnenko, T. E., Zaletov, V. G., Lyssenko, K. A., Starikova, Z. A., Ivakhnenko, E. P., and Minkin, V. I.

Subjects
CATECHOL, CHEMICAL structure, CRYSTALS, COMPLEX compounds, LIGANDS (Chemistry)
Abstract

The reaction of di( tert-butyl) derivatives of pyrocatechol with 2,6-dihydroxyaniline afforded 2,4,6,8-tetra( tert-butyl)-9-hydroxyphenoxazin-1-one. The chemical properties of the reaction product and its ability to form complexes with metal salts as the tridentate ligand were investigated. The structure of hydroxyphenoxazinone was established by X-ray diffraction. [ABSTRACT FROM AUTHOR]

Published
2009
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49. Review: Coordination Chemistry of o -Quinone Complexes.

Author

Kharisov, B. I., Méndez-Rojas, M. A., Garnovskii, A. D., Ivakhnenko, E. P., and Ortiz-Méndez, U.

Subjects
TRANSITION metals, TAUTOMERISM, ISOMERISM, METALS, METAL carbonyls, CARBONYL compounds
Abstract

The structural and tautomeric peculiarities, as well as physical/chemical properties of transition metal complexes with o -quinones are reviewed. Synthetic routes for obtaining these complexes starting from different sources (elemental metals, metal carbonyls, salts, and metal complexes) are described and tabulated. The free-radical properties of metal- o -quinone complexes are discussed. [ABSTRACT FROM AUTHOR]

Published
2002
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