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1.
V. I. Ovcharenko S. V. Fokin G. V. Romanenko V. N. Ikorskii R. Z. Sagdeev D. S. Yachevskii D. L. Chizhov V. N. Charushin 《Russian Chemical Bulletin》2006,55(11):1904-1908
Heterospin complexes of bis(μ2-1,1,2,2,8,8,9,9-octafluorononane-3,5,7-trionato)dicopper(II) ([Cu2L2]) with nitronyl nitroxides 2-(1-methyl-1H-pyrazol-4-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide (2) and 4,4,5,5-tetramethyl-2-(3-pyridinyl)-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide (1) were synthesized and structurally characterized. Crystals of the complexes are formed by the discrete bis[1-methyl-4-(4,4,5,5-tetramethyl-3-oxide-1-oxyl-4,5-dihydro-1H-imidazol-2-yl)-1H-pyrazole]-bis (μ2-1,1,2,2,8,8,9,9-octafluorononane-3,5,7-trionato)dicopper(II) etherate (3) and bis[3-(4,4,5,5-tetramethyl-3-oxide-1-oxyl-4,5-dihydro-1H-imidazol-2-yl)pyridine]-bis (μ2-1,1,2,2,8,8,9,9-octafluorononane-3,5,7-trionato)dicopper(II) (4) molecules. Each Cu atom of the dinuclear chelate fragment coordinates one paramagnetic ligand through the N atom of the
pyrazole or pyridine fragment, respectively. In complex 3, the paramagnetic ligands are located on one side of the plane of the chelate fragment, whereas the ligands in complex 4 are located above and below the plane of the chelate fragment. The magnetic properties of complexes 3 and 4 are determined by dominant antiferromagnetic exchange interactions between the unpaired electrons of the CuII atoms in the dinuclear Cu2L2 moiety.
Dedicated to Academician O. M. Nefedov on the occasion of his 75th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1836–1840, November, 2006. 相似文献
2.
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
3.
V. I. Ovcharenko O. N. Chupakhin I. S. Kovalev E. V. Tretyakov G. V. Romanenko D. V. Stass 《Russian Chemical Bulletin》2008,57(10):2227-2229
The SNH reaction of lithiated 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide with quinoline N-oxide affords 4,4,5,5-tetramethyl-2-(1-oxidoquinolin-2-yl)-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide. 相似文献
4.
Eugene V Tretyakov 《Tetrahedron》2004,60(1):99-103
2-(Pyrazol-1-yl)-, 2-(imidazol-1-yl)-, 2-([1,2,4]triazol-1-yl)-, and 2-(benzotriazol-1-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl were prepared by reactions of 2-bromo-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (NIT-Br) with the corresponding sodium azolides. In prepared 2-(azol-1-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyls, the NIT-NHet bond is readily hydrolyzed. Reduction of imidazole-3-oxide-1-oxyls leads to corresponding 2-(azol-1-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyls, which are much more stable against hydrolysis. The structures of spin-labeled imidazoles, [1,2,4]triazoles and benzotriazoles are confirmed by X-ray analysis, showing that the paramagnetic molecules form packings with motifs from centrosymmetric dimers to topologically linear chains. 相似文献
5.
E. Yu. Fursova O. V. Kuznetsova E. V. Tretyakov G. V. Romanenko A. S. Bogomyakov V. I. Ovcharenko R. Z. Sagdeev V. K. Cherkasov M. P. Bubnov G. A. Abakumov 《Russian Chemical Bulletin》2011,60(5):809-815
Heterospin complexes based on cobalt semiquinolate with stable nitroxides of composition [Co(SQ)2(NIT)2]·8CH2Cl2, [Co(SQ)2(NIT)2]·4MeCN, [Co(SQ)2(IN)2]·5Me2CO, [Co(SQ)2(IN)2]·4MeCN, and [Co(SQ)2(IN)2]·2CH2Cl2·C6H14, where SQ is 3,6-di-tert-butyl-o-benzosemiquinolate, NIT is 4,4,5,5-tetramethyl-2-(1-methyl-1H-imidazol-5-yl)-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl, and IN is the imine analog of NIT, viz., 4,4,5,5-tetramethyl-2-(1-methyl-1H-imidazol-5-yl)-4,5-dihydro-1H-imidazole-1-oxyl, were synthesized. The characteristic feature of these compounds is that they contain two different types
of paramagnetic organic ligands. The X-ray diffraction study showed that the solid phases of the complexes have a molecular
structure. According to the data from thermomagnetic analysis (2–350 K), all complexes exhibit effects of valence tautomerism
at ∼20 °C. It was found that incorporated solvent molecules have an effect on the magnetic anomaly temperature. 相似文献
6.
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
7.
S.I. Zhivetyeva I.A. Zayakin I.Yu. Bagryanskaya E.V. Zaytseva E.G. Bagryanskaya E.V. Tretyakov 《Tetrahedron》2018,74(28):3924-3930
A 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl lithium derivative was found to react with 2-methoxypentafluoro-1,4-naphthoquinone to form a product of addition at the carbonyl function: radical 2-(3,5,6,7,8-pentafluoro-1-hydroxy-2-methoxy-4-oxo-1,4-dihydronaphthalen-1-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl. The yield of the addition product increased with temperature and reached 84% at 0?°C. The reaction of the lithium derivative with hexafluoro-1,4-naphthoquinone gave rise to a product of addition at both carbonyl groups, namely, nitronyl nitroxide diradical 2,3,5,6,7,8-hexafluoro-1,4-bis(4,4,5,5-tetramethyl-3-oxide-1-oxyl-4,5-dihydro-1H-imidazole-2-yl)-1,4-dihydronaphthalene-1,4-diol in a 16% yield. The structures of both mono- and diradical were solved by X-ray diffraction analysis, which revealed formation of an intramolecular H-bond between the OH group and nitroxide oxygen. According to electron paramagnetic resonance (EPR) spectroscopy, the obtained mono- and dinitroxide are prone to spontaneous deoxygenation in a toluene solution to give corresponding iminonitroxides. In water, they are much more stable. 相似文献
8.
Robert Saf Petra Swoboda Klaus Hummel Rainer Czaputa 《Journal of heterocyclic chemistry》1993,30(2):425-428
The preparation of new derivatives of 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxyl 3-oxide as monomers for purely organic polymers with special magnetic properties is described. 3,5-Diethynylbenzaldehyde and 3,5-bis(trimethylsilylethynyl)benzaldehyde were converted to the corresponding 1,3-dihydroxy-4,4,5,5-tetramethylimidazolidine derivatives which were oxidized to stable nitronyl nitroxide radicals. 相似文献
9.
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
10.
E. V. Tretyakov S. V. Fokin E. Yu. Fursova O. V. Kuznetsova G. V. Romanenko R. Z. Sagdeev V. I. Ovcharenko 《Russian Chemical Bulletin》2013,62(8):1803-1808
As part of continuing studies of multispin compounds capable of exhibiting chemomechanical activity, a series of heterospin solids of the composition [Cu(hfac)2L x L′2?x ], [Cu(hfac)2L′], [Cu2(Piv)4L′2]·0.5C6H14, and [Cu2(hfac)2(Piv)2L′2], where hfac is the hexafluoroacetylacetonate anion, L is 4,4,5,5-tetramethyl-2-(1-methyl-1H-imidazol-5-yl)-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl, L′ is the imino nitroxide analog of L, viz., 4,4,5,5-tetramethyl-2-(1-methyl-1H-imidazol-5-yl)-4,5-dihydro-1H-imidazole-1-oxyl, and Piv is the 2,2-dimethylpropionate anion, were synthesized and characterized. The packing of the synthesized crystals of the solid solutions [Cu(hfac)2L x L′2-x ], where L predominates, is similar to that for [Cu(hfac)2L2], and these crystals are able to undergo chemomechanical motion. On the contrary, the crystals of [Cu(hfac)2L x L′2?x ], where L′ predominates, have structural parameters similar to those of [Cu(hfac)2L′2] and do not exhibit thermally activated or photoactivated chemomechanical activity. 相似文献
11.
G. V. Romanenko S. E. Tolstikov E. V. Tretyakov S. V. Fokin V. N. Ikorskii V. I. Ovcharenko 《Russian Chemical Bulletin》2007,56(9):1795-1804
The reactions of bis(hexafluoroacetylacetonato)copper(II) [Cu(hfac)2] with the nitronyl nitroxide biradicals bis[4-(4,4,5,5-tetramethyl-3-oxide-1-oxyl-4,5-dihydro-1H-imidazol-2-yl)pyrazol-1-yl]alkanes (L6, L10, and L12) produced the framework heterospin complex [Cu(hfac)2]2L6 and the layer-polymeric heterospin complexes [Cu(hfac)2]2L10 and {[Cu(hfac)2]2L12} [Cu(hfac)2(PriOH)2], respectively. In the solid state of these compounds, the stereochemical nonrigidity is manifested as a deformation of the
polymethylene fragments-(CH2)n-.
Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1732–1741, September, 2007. 相似文献
12.
E. V. Tret’yakov O. V. Koreneva G. V. Romanenko A. S. Bogomyakov I. Ovcharenko R. Z. Sagdeev 《Journal of Structural Chemistry》2009,50(6):1193-1196
The molecular and crystal structure of Cu(II) bischelate with the deprotonated stable nitroxide radical 4,4,5,5-tetramethyl-2-(2-oxo-1-(4,4,5,5-tetramethylimidazolidine-2-ylidene)ethyl)-4,5-dihydro-1H-imidazole-3-oxide-1-oxylom (HL) are studied. It is revealed that the complex packing is formed of separate CuL2 molecules. Oxygen atoms in >N∸O groups do not participate in Cu2+ ion coordination, and so only weak exchange interactions are observed between paramagnetic centers in CuL2. 相似文献
13.
M. V. Varaksin E. V. Tretyakov I. A. Utepova G. V. Romanenko A. S. Bogomyakov D. V. Stass R. Z. Sagdeev V. I. Ovcharenko O. N. Chupakhin 《Russian Chemical Bulletin》2012,61(7):1469-1473
Cyclic dinitrones underwent nucleophilic substitution of the hydrogen atom in the reaction with a paramagnetic carbanion, the lithium derivative of 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxyl 3-oxide, to give polyfunctional nitronyl nitroxyls. 相似文献
14.
《Journal of Coordination Chemistry》2012,65(13):2215-2222
A new Fe(II) complex, [Fe(HIM2Py)2(N(CN)2)2]?·?2H2O (HIM2py?=?1-hydroxyl-2(2′-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1?H-imidazole), has been synthesized and characterized. The X-ray analysis reveals that HIM2py ligands are coordinated to iron as an unusual six-membered bidentate chelate with κ2N(py), O(HIM) mode. The variable-temperature magnetic susceptibility suggests that weak antiferromagnetic interactions exist in the complex. 相似文献
15.
ukasz Balewski Franciszek Sczewski Patrick J. Bednarski Lisa Wolff Anna Nadworska Maria Gdaniec Anita Kornicka 《Molecules (Basel, Switzerland)》2020,25(24)
The appropriate 1-arylhydrazinecarbonitriles 1a–c are subjected to the reaction with 2-chloro-4,5-dihydro-1H-imidazole (2), yielding 7-(4,5-dihydro-1H-imidazol-2-yl)-2-aryl-6,7-dihydro-2H-imidazo[2,1-c][1,2,4]triazol-3(5H)-imines 3a–c, which are subsequently converted into the corresponding amides 4a–e, 8a–c, sulfonamides 5a–n, 9, ureas 6a–I, and thioureas 7a–d. The structures of the newly prepared derivatives 3a–c, 4a–e, 5a–n, 6a–i, 7a–d, 8a–c, and 9 are confirmed by IR, NMR spectroscopic data, as well as single-crystal X-ray analyses of 5e and 8c. The in vitro cytotoxic potency of these compounds is determined on a panel of human cancer cell lines, and the relationships between structure and antitumor activity are discussed. The most active 4-chloro-N-(2-(4-chlorophenyl)-7-(4,5-dihydro-1H-imidazol-2-yl)-6,7-dihydro-2H-imidazo[2,1-c][1,2,4]triazol-3(5H)-ylidene)benzamide (4e) and N-(7-(4,5-dihydro-1H-imidazol-2-yl)-2-(p-tolyl)-6,7-dihydro-2H-imidazo[2,1-c][1,2,4]triazol-3(5H)-ylidene)-[1,1′-biphenyl]-4-sulfonamide (5l) inhibits the growth of the cervical cancer SISO and bladder cancer RT-112 cell lines with IC50 values in the range of 2.38–3.77 μM. Moreover, N-(7-(4,5-dihydro-1H-imidazol-2-yl)-2-phenyl-6,7-dihydro-2H-imidazo[2,1-c][1,2,4]triazol-3(5H)-ylidene)-4-phenoxybenzenesulfonamide (5m) has the best selectivity towards the SISO cell line and induces apoptosis in this cell line. 相似文献
16.
Chuprakov S. N. Tyurin R. V. Minyaeva L. G. Mezheritskaya L. V. Mezheritskii V. V. 《Russian Journal of Organic Chemistry》2003,39(7):1016-1020
Reactions of 2-(-ethoxyvinyl)-4,4,5,5-tetramethyl-4,5-dihydro-1,3-dioxol-1-ium salts with cyanomethylene compounds gave the corresponding 2-(2-propenylidene)-1,3-dioxolane derivatives which reacted with hydrazine and primary amines to afford, respectively, 3-(2-hydroxy-1,1,2-trimethylpropoxy)pyrazole and 1-substituted 6-amino-5-cyanopyridin-2(1H)-ones. 相似文献
17.
The magnetic properties of the monoradicals 2-(4-phenyl acetylene)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidozolyl-oxyl (1) and 2-(4-phenyl acetylene)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl-3-oxide (2) and the diradicals 2,2'-(1,2-ethynediyldi-4,1-phenylene)bis[4,4,5,5-tetramethyl-4,5-dihydro-1H-imidozolyl-oxyl] (3), 2,2'-(1,2-ethynediyldi-4,1 3,1-phenylene)bis[4,4,5,5-tetramethyl-4,5-dihydro-1H-imidozolyl-oxyl] (4), and 2,2'-(1,2-ethynediyldi-4,1 3,1-phenylene)bis[4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl-3-oxide] (5) are investigated by ab initio quantum chemical methods. The rule of spin alternation in the unrestricted Hartree-Fock (UHF) method clearly shows that the radical sites are antiferromagnetically coupled in 3 and ferromagnetically coupled in 4 and 5, which is consistent with a previous experiment. The molecular geometries are optimized at Hartree-Fock levels. This is followed by single-point calculations using the density functional (UB3LYP) treatment and the multiconfigurational complete active space self-consistent field (CASSCF) methodology. Magnetic exchange coupling constants are determined from the broken-symmetry approach. The calculated J values, -3.60 cm(-1) for 3, 0.16 cm(-1) for 4, and 0.67 cm(-1) for 5, are in excellent agreement with the observed values. Because of the very large size of the diradicals 3-5, the CASSCF (10,10) calculations cannot yield realistic J values. Nevertheless, the CASSCF calculations support the antiferromagnetic nature of the magnetic coupling in 3 and the ferromagnetic nature of the coupling in 4 and 5. The existence of an intramolecular magnetic coupling in 3-5 is also confirmed through computations of the isotropic hyperfine coupling constants for monoradicals 1 and 2 as well as diradicals 3-5. 相似文献
18.
Nosova K. E. Tretyakov E. V. Romanenko G. V. Ovcharenko V. I. 《Russian Chemical Bulletin》2003,52(10):2231-2234
Study of the structures of compounds generated by the reactions of 4,4,5,5-tetramethyl-2-phenyl-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide with trifluoromethanesulfonic and picric acids demonstrated that these reactions produced salts of disproportionation products of nitronyl nitroxyl. 相似文献
19.
E. V. Tretyakov A. V. Mareev M. M. Demina G. V. Romanenko D. V. Stass A. S. Medvedeva V. I. Ovcharenko 《Russian Chemical Bulletin》2009,58(9):1915-1920
Azolyl-substituted nitronylnitroxyls were synthesized using Me 3Si- and Et 3Ge-substituted propynals. When synthesizing 2-[3-(triethylgermyl)-l
H-pyrazol-4-yl]-4,4,5,5-tetramethyl-4,5-dihydro-1 H-imidazole 3-oxide 1-oxyl ( 3b), the cycle was assembled by the reaction of CH2N2 with the corresponding triethylgermylethynyl-substituted nitronylnitroxyl.
In the case of 2-[4-(trimethylsilyl)-l H-1,2,3-triazol-5yl]- (8a) and 2-[4-(triethylgermyl)-1 H-1,2,3-triazol-5-yl]-4,4,5,5-tetramethyl-4,5-dihydro-l H-imidazole 3-oxide l-oxyls (8b), the corresponding heterocyclic aldehydes were synthesized first and then were used for the preparation of compounds 8a and 8b. According to the X-ray diffraction study, the presence of the bulky substituent Me3Si or Et3Ge in the heterocycle causes
its turn by 40.9(2)° in 8a and 33.6(6)° in 3b relative to the plane of the paramagnetic fragment ONCNO. 相似文献
20.
Mei XL Liu RN Wang C Yang PP Li LC Liao DZ 《Dalton transactions (Cambridge, England : 2003)》2012,41(10):2904-2909
Three novel ring-like compounds formulated as [Ln(Phtfac)(3)(NITpPy)](2) (Ln(III) = Gd 1, Tb 2, Dy 3; HPhtfac = 4,4,4-trifluoro-1-phenylbutane-1,3-dione; NITpPy = 2-(4-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl-3-oxide) were synthesized and structurally and magnetically characterized. Three compounds possess cyclic dimer structure in which each pyridine substituted radical links two different metal ions through the oxygen of nitroxide group and the pyridine nitrogen. DC magnetic studies show the Ln(III) ion interacts ferromagnetically with the directly bonding nitronyl nitroxide. Both Tb(III) and Dy(III) clusters show frequency-dependent ac magnetic susceptibilities, indicating single-molecule magnet behavior. It is demonstrated that the β-diketonate coligand may play an important role in determining the magnetic relaxation for the lanthanide-radical system. 相似文献