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1.
Dinuclear copper(II) complexes with acyldihydrazones of 2-hydroxy-5-nitroacetophenone (H4L) of the composition Cu2(Py)xL·mEtOH were synthesized and characterized. In these complexes, the coordination polyhedra of the copper atoms are linked to
each other by a polymethylene chain of different lengths, from one to five monomer units. The structure of the [Cu2L·4Mrf] complex (Mrf is morpholine) based on acyldihydrazone of malonic acid was established by X-ray diffraction. The copper(II) atoms in this complex are [4+1]-coordinated and are spaced by 6.94 Å. At room temperature, the signal in the ESR spectra
of solutions of the complexes based on acyldihydrazones of malonic, succinic, glutaric, and adipic acids has a seven-line
hyperfine structure with the constant of (35.3–38.8)·10−4 cm−1 (g = 2.109–2.112) due to exchange interactions between unpaired electrons and two equivalent copper nuclei. An increase in the
length of the polymethylene chain to five monomer units hinders exchange interactions, and the ESR signal of the complex based
on acyldihydrazone of pimelic acid has a four-line hyperfine structure with a
Cu = 72.7·10−4 cm−1 typical of mononuclear copper(II) complexes.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 229–234, February, 2007. 相似文献
2.
G. M. Larin A. N. Gusev Yu. V. Trush K. V. Rabotyagov V. F. Shul’gin G. G. Aleksandrov I. L. Eremenko 《Russian Chemical Bulletin》2007,56(10):1964-1971
Spacer-armed dinuclear copper(II) complexes with condensation products of isophthalic and terephthalic acid dihydrazides with salicylaldehyde and 2-hydroxyacetophenone
were synthesized and studied by EPR and X-ray diffraction. The compositions and structures of most of the complexes were determined
by elemental analysis, thermogravimetric analysis, and IR spectroscopy. The structure of the copper(II) complex with acyldihydrazone of salicylaldehyde and 1,3-benzenedicarboxylic acid (H4L) with the composition [Cu2L1·2morph·MeOH] (morph is morpholine) was established by X-ray diffraction. The CuII atoms are spaced by 10.29 Å and are structurally nonequivalent. One copper cation has a square-planar coordination formed
by donor atoms (2 N + O) of the doubly deprotonated acylhydrazine fragment and the N atom of the morpholine molecule. The
second copper atom is additionally coordinated by a methanol molecule through the oxygen atom, so that this copper atom is
in a tetragonal-pyramidal coordination with the oxygen atom in the axial position. The EPR spectra of liquid solutions of
the complexes based on 1,4-benzenedicarboxylic acid acyldihydrazones and 1,3-benzenedicarboxylic acid bis(salicylidene)hydrazone
at room temperature show a four-line hyperfine structure with the constant a
Cu = 54.4–67.0·10−4 cm−1 (g = 2.105–2.147), which is indicative of the independent behavior of the paramagnetic centers. The EPR spectrum of a solution
of the complex based on isophthalic acid and 2-hydroxyacetophenone shows the seven-line hyperfine structure corresponding
to two equivalent copper nuclei (g = 2.11, a
Cu = 36.5·10−4 cm−1).
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1898–1905, October, 2007. 相似文献
3.
Kinetics of hydrogen peroxide decomposition in the presence of the tetraaquapalladium(II) complex in an aqueous solution at
40–70 °C was studied. The reaction rate is the first order with respect to the concentration of both PdII and H2O2 and the negative first order with respect to perchloric acid. Using free radicals traps, the reaction mechanism was found
to differ from the traditional free-radical mechanism known for d-metal aqua ions and proceeds without generation of hydroxyl
radicals. The kinetic data obtained suggest a mechanism involving the formation of an intermediate palladium complex with
oxygen.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1077–1082, May, 2005. 相似文献
4.
T. V. Mitkina D. Yu. Naumov O. A. Gerasko F. M. Dolgushin C. Vicent R Llusar M. N. Sokolov V. P. Fedin 《Russian Chemical Bulletin》2004,53(11):2519-2524
The inclusion compound of macrocyclic cavitand cucurbit[8]uril (CB[8]) with the nickel(II) complex containing the tetraazamacrocyclic ligand cyclam, {[Ni(cyclam)]@CB[8]}Cl2··16H2O (1), and the inclusion compounds of CB[8] with the copper(II) bis-ethylene-diamine complex, {trans-[Cu(en)2(H2O)2]@CB[8]}Cl2·{CB[8]}·42H2O (2a) and {trans-[Cu(en)2(H2O)2]@CB[8]}Cl2·17H2O (2b), were synthesized and characterized by X-ray diffraction analysis, IR and ESR spectroscopy, and electrospray mass spectrometry. Guest—host inclusion compounds can be directly synthesized starting from a metal complex and cucurbit[8]uril, as was exemplified by the preparation of compounds 2a and 2b.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2414–2419, November, 2004. 相似文献
5.
E. K. Beloglazkina A. G. Majouga A. A. Moiseeva M. G. Tsepkov N. V. Zyk 《Russian Chemical Bulletin》2007,56(2):351-355
The reaction of 5-[2-(methylthio)ethyl]-3-phenyl-2-thioxoimidazolidin-4-one (LH) with salts MCl2· xH2O (M = Co, Ni, Cu; x = 2, 6) afforded the [M(L)Cl]n complexes of NiII, CoII, and CuII. The electrochemical behavior of the LH ligand and its complexes was studied using the cyclic voltammetry and rotating disk
electrode techniques. The structures of the synthesized compounds were determined by the data of UV—Vis and IR spectroscopy,
mass spectrometry, and electrochemical characteristics.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 339–343, February, 2007. 相似文献
6.
Critical phenomena in ethylbenzene oxidation in an acetic acid solution at high cobalt(III) concentrations (from 0.01 to 0.2 mol L−1) were studied at 60–90 °C by the gasometric (O2 absorption), spectrophotometric (CoIII accumulation), and chemiluminescence (relative concentration of radical RO2
·) methods. These phenomena are as follows: (1) increase in the oxidation rate above the theoretical limiting rate of radical
autooxidation (k
3
2[RH]2/2k
6); (2) achievement of a maximum and a sharp decrease in the oxidation rate and concentration of radical RO2
· with the further increase in the CoII concentration (existence of critical concentrations). The oxidation rate increases due to the reaction RO2
· + CoII + H+ → → ROOH + CoIII, while the inhibition effect is caused by the decay of RO2
· radical involving two cobalt(II) atoms: RO2
· + 2 CoII → R′CO + CoIII + CoII (k(70 °C) ≈ 300 L2 mol−2 s−1). The detailed scheme (through the formation of the complex RO2
·CoII) describing the conjugation of these reactions was proposed.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1823–1827, August, 2005. 相似文献
7.
The sorption of anions H2PO4
−, HPO4
2−, PO4
3−, [Fe(CN)6]3−, and [Fe(CN)6]4− from aqueous solutions on the surface of FeIII and ZrIV oxyhydroxide hydrogels freshly precipitated at pH 4–13 was studied. The region of sorbate concentrations was from 0.00025
to 0.06 mol L−1. The plots of the anion uptakes vs. their equilibrium concentrations are represented by isotherms of the first type, which are well described by the Langmuir
equation if the quantity of the amount adsorbed is expressed as mol-site g−1. The maximum uptakes and constants of the Langmuir equation were calculated. The phosphate anions occupy the same number
of sorption sites on the sorbents precipitated at different pH. The average specific content of sorption sites for the ferro-
and zirconogels in the metastability period is independent of the pH of their precipitation, being 3.1·10−3 and 3.2·10−3 mol-site g−1, respectively. The [Fe(CN)6]3− and [Fe(CN)6]4− anions are sorbed only on the positively charged sites of the hydrogels and occupy not more than 2·10 mol-site g−1 in the studied interval of pH of precipitation.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1736—1741, August, 2005. 相似文献
8.
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
9.
V. Ya. Kavun A. E. Panasenko L. A. Zemnukhova A. B. Slobodyuk 《Russian Chemical Bulletin》2008,57(7):1379-1383
Ionic mobility in the NaSbClF3 · H2O, KSbClF3, and NH4SbClF3 fluorochloride complexes was studied by 1H and 19F NMR spectroscopy in the temperature interval from 150 to 480 K. The types of ionic motions in the compounds were determined.
Their physicochemical characteristics were compared with those of the earlier studied sodium, potassium, and ammonium tetrafluoroantimonates(iii). The replacement of one F atom by the Cl atom in MSbF4 (M = Na, K, NH4) changes both the structure of the Sb polyhedra forming the structure of the antimony(iii) fluorochloride complex and the character of ionic motions in the compounds. The ionic conductivity in the 324–436 K range
was determined for NH4SbClF3: σ = 1.07 · 10−4 S cm−1 at T = 423 K.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1353–1357, July, 2008. 相似文献
10.
A. V. Kulik O. N. Temkin L. G. Bruk V. E. Zavodnik V. K. Belsky V. V. Minin 《Russian Chemical Bulletin》2005,54(6):1391-1397
New PdI and Pd0 carbonyl bromide complexes co-existing in the same crystal were synthesized and studied by X-ray diffraction analysis. The
crystals consist of dimeric complex anions composed of the central Pd(μ-CO)2Pd fragment and four partially disordered terminal ligands (CO and Br−). The complexes were characterized by IR, ESR, and X-ray photoelectron spectroscopy.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1349–1355, June, 2005. 相似文献
11.
The catalytic reduction of acetophenone, methyl α-acetamidocinnamate, and dimethyl itaconate with alcohol-modified sodium borohydride was studied in the presence of complexes CoCl2·L2 (L2 are chiral C
2-symmetric diamines: (4S,5S)-2,2-dimethyl-4,5-bis(aminomethyl)-1,3-dioxolane, (4S, 5S)-2,2-dimethyl-4,5-bis(methylaminomethyl)-1,3-dioxolane, (4S, 5S)-2,2-dimethyl-4,5-bis(dimethylaminomethyl)-1,3-dioxolane, and (4S, 5S)-2,2-dimethyl-4,5-bis(diphenylaminomethyl)-1,3-dioxolane). The maximum enantiomeric excess of (S)-1-phenylethanol was 24%, that of dimethyl α-methylsuccinate was 38%.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 342–347, February, 2005. 相似文献
12.
L. O. Nindakova N. N. Chipanina V. K. Turchaninov M. V. Ustinov B. A. Shainyan 《Russian Chemical Bulletin》2005,54(10):2343-2347
The reaction of di-μ-chlorobis(1,5-cyclooctadiene)dirhodium with (4S, 5S)-2,2-dimethyl-4,5-bis(methylaminomethyl)-1,3-dioxolane (1) gave the complex [Rh(cod)(1)]Cl (cod is 1,5-cyclooctadiene). The composition of the complexes CoCl2 · L2 and [Rh(cod)(L2)]X (L2 = 1, (4S,5S)-2,2-dimethyl-4,5-bis(aminomethyl)-1,3-dioxolane, and (4S, 5S)-2,2-dimethyl-4,5-bis(dimethylaminomethyl)-1,3-dioxolane; X = Cl, TfO) was studied using IR and 1H NMR spectroscopy. In the RhI cyclooctadienediamine complexes, the diene molecule forms a stronger bond with the metal atom than that in the cyclooctadienediphosphine
analogs.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2270–2274, October, 2005. 相似文献
13.
An enzymatic method for determining L-malic acid in wine based on an L-malate sensing layer with nicotinamide adenine dinucleotide (NAD+), L-malate dehydrogenase (L-MDH) and diaphorase (DI), immobilized by sol-gel technology, was constructed and evaluated. The sol-gel glass was prepared
with tetramethoxysilane (TMOS), water and HCl. L-MDH catalyzes the reaction between L-malate and NAD+, producing NADH, whose fluorescence (λ
exc = 340 nm, λ
em = 430 nm) could be directly related to the amount of L-malate. NADH is converted to NAD+ by applying hexacyanoferrate(III) as oxidant in the presence of DI. Some parameters affecting sol-gel encapsulation and the
pH of the enzymatic reaction were studied. The sensing layer has a dynamic range of 0.1–1.0 g/L of L-malate and a long-term storage stability of 25 days. It exhibits acceptable reproducibility [s
r(%)≈10] and allows six regenerations. The content of L-malic acid was determined for different types of wine, and polyvinylpolypyrrolidone (PVPP) was used as a bleaching agent
with red wine. The results obtained for the wine samples using the sensing layer are comparable to those obtained from a reference
method based on UV-vis molecular absorption spectrometry, if the matrix effect is corrected for. 相似文献
14.
E. Yu. Fursova O. V. Kuznetsova V. I. Ovcharenko G. V. Romanenko A. S. Bogomyakov M. A. Kiskin I. L. Eremenko 《Russian Chemical Bulletin》2007,56(9):1805-1808
A method was developed for the synthesis of mixed-metal heterospin compounds with the direct coordination of the nitroxide
fragment based on the replacement of acetonitrile molecules in the heterotrinuclear complex [Co2Gd(NO3)Piv6(CH3CN)2] with nitroxide molecules. The molecular and crystal structure of the heterospin mixed-ligand heterotrinuclear CoII, GdIII, CoII complex [Co2Gd(NO3)Piv6(NIT-Me)2], where NIT-Me is stable nitronyl nitroxide, was established. The magnetic properties of this complex were investigated in
the temperature range of 2–300 K. The coordination of nitroxide groups to CoII ions is responsible for strong exchange interactions between the unpaired electrons in the exchange clusters {>-·O-CoII}, resulting in the virtually complete spin coupling between each coordinated >N-·O group and one of the unpaired electrons
of each CoII ion at temperatures below 200 K.
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. 1742–1745, September, 2007. 相似文献
15.
The Becke3LYP functional of DFT theory was used to investigate molecular structure and sodium affinity of the systems CH3CO2Na (1), CH3–O–SO3Na (2), CH3–NH–SO3Na (3), saccharide_1Na2 (4), saccharide_2Na (5), saccharide_3Na3 (6), saccharide_4Na2 (7), and saccharide_5Na2 (8), respectively, which are models of N- and O-sulfate glycosaminoglycans. Interaction enthalpies, entropies and Gibbs energies of the sodium-coordinated systems in the
gas phase were determined with the B3LYP/6-311+G(d,p) and B3LYP/6-31+G(d) methods. The computed Gibbs energies, ΔG
o
, of model systems 1–3 are negative and span a rather broad energy interval (from −500 to −1,500 kJ mol−1). Gibbs interaction energies for sodium acetate, sodium sulfate and sodium sulfamate functions of the five saccharides, systems
4–8 are always lower than those values found for the model compounds 1–3. The ionization of sodium salts of saccharides studied in gas phase is in most cases connected with considerable conformational
rearrangement of the ionic species. This rearrangement causes an additional energetic stabilization of anionic species and
is connected with the substantial release of entropy. 相似文献
16.
E. V. Starodubtseva O. V. Turova M. G. Vinogradov L. S. Gorshkova V. A. Ferapontov 《Russian Chemical Bulletin》2005,54(10):2374-2378
The rate of hydrogenation of γ-ketoesters MeCOCH2CH2COOR (R = Et, Pri, But) in the presence of the chiral RuII—BINAP catalyst (BINAP is 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) greatly increases upon the addition of 5–10 equivalents
of HCl with respect to ruthenium. In the hydrogenation of ethyl levulinate, the optically active γ-hydroxy ester initially
formed would cyclize by ∼95% to give γ-valerolactone with optical purity of 98–99% ee. When the Ru(COD)(MA)2—BINAP—HCl catalytic system is used (COD is 1,5-cyclooctadiene, MA is 2-methylallyl), complete conversion of the ketoester
(R = Et) in EtOH is attained in 5 h at 60 °C under an H2 pressure of 60–70 atm.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2301–2304, October, 2005. 相似文献
17.
The polymerization of o-phenylenediamine (OPD) on l-tyrosine (Tyr) functionalized glassy carbon electrode (GCE) and its electro-catalytic oxidation towards ascorbic acid (AA)
had been studied in this report. l-Tyrosine was first covalently grafted on GCE surface via electrochemical oxidation, which was followed by the electrochemical
polymerization of OPD on the l-tyrosine functionalized GCE. Then, the poly(o-phenylenediamine)/l-tyrosine composite film modified GCE (POPD-Tyr/GCE) was obtained. X-ray photo-electron spectroscopy (XPS), field emission
scanning electron microscope (SEM), and electrochemical techniques have been used to characterize the grafting of l-tyrosine and the polymerization and morphology of OPD film on GCE surface. Due to the doping of the carboxylic functionalities
in l-tyrosine molecules, the POPD film showed good redox activity in neutral medium, and thus, the POPD-Tyr/GCE exhibited excellent
electrocatalytic response to AA in 0.1 mol l−1 phosphate buffer solution (PBS, pH 6.8). The anode peak potential of AA shifted from 0.58 V at GCE to 0.35 V at POPD-Tyr/GCE
with a greatly enhanced current response. A linear calibration graph was obtained over the AA concentration range of 2.5 × 10−4–1.5 × 10–3 mol l−1 with a correlation coefficient of 0.9998. The detection limit (3δ) for AA was 9.2 × 10−5 mol l−1. The modified electrode showed good stability and reproducibility and had been used for the determination of AA content in
vitamin C tablet with satisfactory results. 相似文献
18.
The hexanuclear complex [Fe6(O)2(CH2O2) (OOCCMe3)12 (THF)2]·THF was synthesized. The characteristic feature of this complex is the presence of the methanedithiolate bridge.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 795–797, March, 2005. 相似文献
19.
Yodthong Baimark Mangkorn Srisa-ard Jirasak Threeprom Nual-Anong Narkkong 《Colloid and polymer science》2007,285(13):1521-1525
Nanoparticle colloids of methoxy poly(ethylene glycol)-b-poly(D,L-lactide) (MPEG-b-PDLL) diblock copolymer were prepared by a modified spontaneous emulsification solvent diffusion method using acetone/ethanol
as the mixture organic solvents. The MPEG-b-PDLL was synthesized by ring-opening polymerization of D,L-lactide using stannous octoate and MPEG with molecular weight of 5,000 g/mol as the initiating system. The MPEG-b-PDLL obtained was an amorphous polymer with molecular weight of 73,600 g/mol. Influences of acetone/ethanol (v/v) ratios
and Tween 80 surfactant concentrations on characteristics of the colloidal nanoparticles were investigated and discussed.
Light-scattering analysis showed that average diameters of the surfactant-free colloidal nanoparticles were in the range of
86–124 nm. The nanoparticle sizes decreased as the ethanol ratio increased. The Tween 80 did not show the significant effect
on the nanoparticle sizes. Scanning electron micrographs of dried nanoparticles that demonstrated the aggregation of most
particles suggested they were the soft nanoparticles. However, the dried nanoparticle morphology can be observed from scanning
electron microscopy as having a spherical shape and smooth surfaces. 相似文献
20.
E. K. Beloglazkina I. V. Yudin A. G. Majouga A. A. Moiseeva A. I. Tursina N. V. Zyk 《Russian Chemical Bulletin》2006,55(10):1803-1809
The reactions of 2-(2-pyridyl)benzothiazole (1) with MX2·nH2O salts (M = NiII, CoII, or CuII; X = Cl or ClO4; n = 0–2) in EtOH afforded the corresponding complexes. Depending on the nature of the counterion in the starting metal salt,
the reactions give compounds of composition M(1)Cl2·nH2O or Cu(1)2(ClO4)2·H2O. The molecular and crystal structure of the CuII(1)2(ClO4)2·H2O complex was established by X-ray diffraction. The copper atom in this complex has a distorted tetragonal-pyramidal ligand
environment and is coordinated by four nitrogen atoms of two ligand molecules and one water molecule. Electrochemical study
of the ligand and the resulting complexes by cyclic voltammetry and at a rotating disk electrode demonstrated that ligand
1 stabilizes reduced forms of complexes containing Ni, Co, or Cu atoms in the oxidation state +1.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1738–1744, October, 2006. 相似文献