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Petrov P. A. Tret"yakov E. V. Romanenko G. V. Ovcharenko V. I. Sagdeev R. Z. 《Russian Chemical Bulletin》2004,53(1):109-113
The reaction of CuCl2 with deprotonated 2-(2-hydroxy-3-nitrophenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide afforded a bis-chelate complex containing seven-membered metallocycles. 相似文献
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V V Ovcharenko K Pihlaja D Matosiuk 《Rapid communications in mass spectrometry : RCM》2001,15(24):2502-2508
The 70-eV electron ionisation (EI) mass spectra of the title compounds show clear differences between the 5-oxo and 7-oxo isomers due to regioselective fragmentations involving the ester function. Exceptionally abundant metastable peaks due to molecular ions fragmenting to [M -CO2](+.) were observed exclusively for the 7-oxo isomers, suggesting that the sufficiently long-lived molecular ions undergo a slow rearrangement preceding this fragmentation reaction. The results are contrasted to the available literature data on the ester group fragmentations involving the loss of CO2 and the EI mass spectrometry of pyrimidone beta-oxo esters. A reaction mechanism is proposed for the elimination of CO2 following ethyl group migration to the pyrimidone carbonyl oxygen. 相似文献
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A.?D.?FedorenkoEmail author L.?N.?Mazalov E.?Yu.?Fursova V.?I.?Ovcharenko A.?V.?Kalinkin S.?A.?Lavrukhina 《Journal of Structural Chemistry》2017,58(6):1166-1172
The electronic structure of hexanuclear Mn(II,III) pivalate complexes with tetrahydrofuran and isonicotinamide are studied by X-ray photoelectron spectroscopy and X-ray emission spectroscopy. It is shown that when isonicotinamide substitutes for tetrahydrofuran the spin state of manganese ions is retained; the electron density increases on the manganese and oxygen atoms of the [Mn6(O)2Piv10] core. 相似文献
38.
E. Yu. Fursova O. V. Kuznetsova G. V. Romanenko A. S. Bogomyakov V. I. Ovcharenko 《Russian Chemical Bulletin》2010,59(2):337-341
The heterospin mixed-ligand complex [Ni6(OH)4Piv4(hfac)4(NIT-Ph)2] (1) (NIT-Ph is 4,4,5,5-tetramethyl-2-phenyl-4,5-dihydro-1H-imidazol-1-oxyl 3-oxide, hfac is hexafluoroacetylacetonate, and Piv is pivalate) was synthesized. The method for the synthesis
of complex 1 is based on the replacement of acetone molecules in the hexanuclear complex containing the hexafluoroacetylacetonate and
pivalate ligands [Ni6(OH)4Piv4(hfac)4(Me2CO)4] by NIT-Ph molecules. Two monodentate NIT-Ph molecules replace four acetone molecules, because the coordination of the O
atom of the nitroxide group results in the blocking of one of the positions in the coordination environment of NiII the access to which is hindered by the phenyl ring of NIT-Ph. As a result, these ions are in a square-pyramidal environment
unusual of NiII. In the low-temperature range, the dependence of the magnetization of 1 on the magnetic field is described by the Brillouin function. The reaction of [Ni6Piv4(hfac)4(OH)4(Me2CO)4] with the nitronyl nitroxide radicals 4,4,5,5-tetramethyl-2-(4-pyridyl)-4,5-dihydro-1H-imidazol-1-oxyl 3-oxide (NIT-p-Py) or 4,4,5,5-tetramethyl-2-(1-methyl-1H-imidazol-5-yl)-4,5-dihydro-1H-imidazol-1-oxyl 3-oxide (NIT-Iz) containing the pyridine or 1-methylimidazol-5-yl substituent, respectively, in the side
chain is accompanied by the decomposition of the polynuclear fragment and affords the mononuclear complexes Ni(hfac)2(NIT-p-Py)2 and Ni(hfac)2(NIT-Iz)2, respectively. The reaction of 4,4,5,5-tetramethyl-2-(1-methyl-1H-imidazol-5-yl)-4,5-dihyd-ro-1H-imidazol-1-oxyl (Im-Iz), which is the imine analog of NIT-Iz, with [Ni6Piv4(hfac)4(OH)4(Me2CO)4] afforded the decanuclear complex [Ni10(OH)8Piv4(hfac)8(Im-Iz)2(H2O)6]. The molecular and crystal structures of all heterospin compounds were determined, and the magnetic properties of all compounds
were investigated in the 2–300 K temperature range. 相似文献
39.
L. N. Mazalov A. D. Fedorenko V. I. Ovcharenko E. V. Tretyakov E. Yu. Fursova N. A. Kryuchkova 《Journal of Structural Chemistry》2011,52(1):102-108
The N(1s) and O(1s) XPS spectra of stable nitroxyl radicals and molecules with a related heterocycle structure: 4,4,5,5-tetramethyl-2-phenyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl, 4,4,5,5-tetramethyl-2-(3-nitrophenyl)-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl, 4,4,5,5-tetramethyl-2-(2-hydroxyphenyl)-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl, 4,4,5,5-tetramethyl-2-(2-hydroxy-3-nitrophenyl)-4,5-dihydro-1Himidazole-3-oxide-1-oxyl, and 4,4,5,5-tetramethyl-2-phenyl-4,5-dihydro-1H-imidazole-3-oxide were studied. The possibility to apply X-ray electron spectra for investigation of the charge electron and spin density distribution on free radical atoms and at their coordination by a metal is considered. 相似文献
40.
S. V. Fokin V. I. Ovcharenko G. V. Romanenko E. V. Tretyakov A. S. Bogomyakov L. V. Saloutina T. I. Filyakova V. I. Saloutin V. N. Charushin O. N. Chupakhin 《Russian Chemical Bulletin》2011,60(5):816-823
The first heterospin compounds based on bis(1,1,1,3,5,5,5-heptafluoro-4-iminopent-2-ene-2-aminato)copper(ii) (CuL2) and nitronyl nitroxide radicals, 2-R-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyls (NIT-R, where R = H, Me, Ph, and 1-methylpyrazol-4-yl), were synthesized and structurally characterized.
An important peculiarity of the structure of synthesized solid phases is the formation of a supramolecular structure due to
hydrogen bonds between the oxygen atoms of the nitronyl nitroxide fragments of NIT-R and the hydrogen atoms of the NH groups
of CuL2. 相似文献