共查询到20条相似文献,搜索用时 31 毫秒
1.
G. N. Pirogova N. M. Panich R. I. Korosteleva Yu. V. Tyurkin Yu. V. Voronin 《Russian Chemical Bulletin》1994,43(10):1634-1636
The catalytic activity of MIMII
2O3 spinel-type complex oxides (MI = Cu, Ni, Mn, Zn, Mg, Co, MII = Co, Cr, Al) in the oxidation of CO and ethylbenzene has been investigated. The Co-containing catalysts were more active than the Cr- and Al-containing catalysts. The nature of the cation influenced the catalytic activity. Higher activities were observed for the catalysts containing two transition elements. A correlation between the catalytic and adsorption properties was established.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1730–1732, October, 1994. 相似文献
2.
N. M. Panich G. N. Pirogova R. I. Korosteleva Yu. V. Voronin 《Russian Chemical Bulletin》1999,48(4):694-697
The catalytic activity of perovskites MIMIIO3 (MI=La; MII=Co, Mn, Cr, Al, Ni, and V) and MICoO3 (M=Y, Nd, Sm, and Er) in the oxidation of CO, propylene, and ethylbenzene was investigated. The highest activity was observed
for the MICoO3 catalysts with perfect perovskite structure. The nature of the rare-earth element has no influence on the catalytic activity.
Deformation of the octahedral coordination of the metal was found for the less active catalysts. The interaction of gases
(CO, CO+air) with the catalyst surface was investigated. The more active catalysts adsorb a greater amount of O2, and the adsorption occurs in the temperature region of the oxidation reaction. The activities of the perovskite- and spinel-type
catalysts were compared under similar conditions.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 698–701, April, 1999. 相似文献
3.
G. N. Pirogova R. I. Korosteleva N. M. Panich T. A. Lagutina Yu. V. Voronin 《Russian Chemical Bulletin》1994,43(4):551-554
The catalytic activity of MIMIIO3] perovskite-type complex oxides (MI = La, Y, Nd, Yb; MII = Co, Mn, Ni) in the oxidation of CO, propylene, benzene, ethylbenzene,o-xylene, and ethyl acetate was investigated. The Co-containing catalysts were shown to be more active in the oxidation than the Mn-containing catalysts. A relationship between the catalytic and adsorption properties was established.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 602–605, April, 1994. 相似文献
4.
Low-temperature (20—400 °C) exoemission of negative charges from mixed oxides having the perovskite structure M1M2O3 (M1 = La; M2 = Co, Mn, Ni) or the spinel structure M1M2
2O4 (M1 = Cu; M2 = Fe, Co, Cr) was studied. The relationship between the catalytic activity in CO, ethylbenzene, and propylene oxidation and the emissivity of the oxides was elucidated. The role of weakly bound oxygen and variable-valence ions in the exoemission and redox catalysis by mixed oxides is discussed. 相似文献
5.
C. Marhag D. Ben Hassen-Chehimi H. Said 《Journal of Thermal Analysis and Calorimetry》2006,86(1):249-254
The thermodynamic
exploitation of the solid–liquid equilibria in the MIPO3–Pb(PO3)2, MIPO3–Cu(PO3)2
and MIPO3–Ce(PO3)3
systems (with M
I=Li,
Na, K, Rb, Cs, Ag, Tl) is carried out using a semi-empirical equation of the
liquidus curves already used with success for similar binary systems.
The enthalpy of fusion is calculated for each pure polyphosphate on
the assumption that the liquid solution is ideal and only formed by MIPO3
and M(PO3)q entities (q=2 for Pb and Cu, q=3
for M=Ce). In the most binary systems,
a wide difference between the calculated values of the melting enthalpies
of these polyphosphates and the measured ones determined from the DTA curves,
was observed. This difference is probably due to the existence of some molecular
associations in the liquid phase. 相似文献
6.
Nanthawat Wannarit Viwat Hahnvajanawong Chaveng Pakawatchai Sujittra Youngme 《Transition Metal Chemistry》2012,37(1):79-84
Two multiple-layer heterometallic MnII–AgI coordination polymers, {MnII(ampyz)(H2O)[Ag2I(CN)3][AgI(CN)2]·ampyz}
n
(1) and {[MnII(benzim)2[AgI(CN)2]2][(benzim)AgI(CN)]·H2O}
n
(2) where ampyz = 2-aminopyrazine and benzim = benzimidazole, have been prepared and structurally characterized. Compound 1 reveals a multiple-layer two-dimensional network with strong hexanuclear argentophilic interactions leading to an infinite
three-dimensional framework. Compound 2 has an unprecedented double-layer two-dimensional squared grid-type network with (4,4) topology through AgI···AgI and π–π interactions between two adjacent squared layers. These double-layer networks of 2 are linked to others by π–π interactions, leading to a three-dimensional framework. 相似文献
7.
The reaction of [M(L)]Cl2 · 2H2O (M = Ni2+ and Cu2+, L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane) with 1,1-cyclobutanedicarboxylic acid (H2-cbdc) generates 1D and 2D hydrogen-bonded infinite chains [Ni(L)(H-cbdc−)2] (1) and [Cu(L)(H-cbdc−)2] (2). (H-cbdc− = cyclobutane-1-carboxylic acid-1-carboxylate). These complexes have been characterized by X-ray crystallography, spectroscopy,
and cyclic voltammetry. The crystal structure of 1 shows a distorted octahedral coordination geometry around the nickel(II) ion, with four secondary amines and two oxygen atoms
of the H-cbdc− ligand at the trans position. In 2, the coordination environment around the central copper(II) ion shows a Jahn–Teller distorted octahedron with four Cu–N bonds
and two long Cu–O distances. The cyclic voltammogram of the complexes undergoes two one-electron waves corresponding to MII/MIII and MII/MI processes. The electronic spectra and electrochemical behavior of the complexes are significantly affected by the nature
of the axial H-cbdc− ligand. 相似文献
8.
G. A. Korneeva I. I. Kerov Z. Kh. Ibragimova V. I. Kurkin K. L. Makovetsky E. V. Slivinsky 《Russian Chemical Bulletin》1998,47(2):360-362
It was found that carboxylation of norbornene (nbn) in the presence of the PdCl2−PPh3−HCl catalytic system is accompanied by alternating copolymerization ofnbn with carbon monoxide to form norbornanecarboxylic acid (yield ∼20%) and anbn-CO copolymer (yield ∼80%,M
w=1600,M
w/M
n=1.6). The PdII salt of poly(norbornaneketone)carboxylic acid is a highly active catalyst for the carbomethoxylation of propylene.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 368–370, February, 1998. 相似文献
9.
New divalent transition metal 3,5-pyrazoledicarboxylate
hydrates of empirical formula Mpz(COO)2(H2O)2,
where M=Mn, Co, Ni, Cu, Zn and Cd (pz(COO)2=3,5-pyrazoledicarboxylate),
metal hydrazine complexes of the type Mpz(COO)2N2H4
where M=Co, Zn or Cd and Mpz(COO)2nN2H4·H2O,
where n=1 for M=Ni
and n=0.5 for M=Cu
have been prepared and characterized by physico-chemical methods. Electronic
spectroscopic data suggest that Co and Ni complexes adopt an octahedral geometry.
The IR spectra confirm the presence of unidentate carboxylate anion (Δν=νasy(COO–)–νsym(COO–)>215
cm–1) in all the complexes and bidentate
bridging hydrazine (νN–N=985–950 cm–1)
in the metal hydrazine complexes. Both metal carboxylate and metal hydrazine
carboxylate complexes undergo endothermic dehydration and/or dehydrazination
followed by exothermic decomposition of organic moiety to give the respective
metal oxides as the end products except manganese pyrazoledicarboxylate hydrate,
which leaves manganese carbonate. X-ray powder diffraction patterns reveal
that the metal carboxylate hydrates are isomorphous as are those of metal
hydrazine complexes of cobalt, zinc and cadmium. 相似文献
10.
V. V. Sharutin V. S. Senchurin O. K. Sharutina O. A. Fastovets A. P. Pakusina 《Russian Journal of Inorganic Chemistry》2010,55(9):1410-1414
Complexes Ph3(n-Pr)P2+[CoI4]2− (I) and [Ph3(n-Am)P]2+ [CoI4]2− (II) were synthesized by reactions of triphenyl(alkyl)phosphonium iodide with cobalt(II) iodide in acetone. According to the
X-ray diffraction data, complexes I and II consist of tetrahedral triphenyl(alkyl)phosphonium cations (for I, P-C is 1.787(4)–1.804(4) ? and CPC is 106.73(18)°–111.4(18)°; for II P-C is 1.786(6)–1.802(6) ? and CPC is 107.6(3)°–111.7(3)°) and [CoI4]2− anions (Co-I 2.5923(6)–2.6189(6) ?, ICoI 101.86(2)°–113.25(2)° for I; Co-I 2.5899(9)–2.6171(9) 107.01(3)°–110.47(3)° for II). 相似文献
11.
Synthesis and X-ray diffraction study of manganites LaM 3I M 3II Mn4O12(MI= Li, Na, K; MII = Mg, Ca)
B. K. Kasenov E. S. Mustafin M. A. Akubaeva Zh. I. Sagintaeva S. T. Edilbaeva Sh. B. Kasenova S. Zh. Davrenbekov Zh. S. Bekturganov 《Russian Journal of Inorganic Chemistry》2007,52(9):1340-1342
Manganites LaM
3
I
M
3
II
Mn4O12(MI = Li, Na, K; MII = Mg, Ca) have been synthesized for the first time by the solid-phase reactions of lanthanum(III) and manganese(II) oxides
and lithium, sodium, potassium, magnesium, and calcium carbonates. X-ray diffraction shows that all of them crystallize in
the cubic crystal system. Their unit cell parameters are determined.
Original Russian Text ? B.K. Kasenov, E.S. Mustafin, M.A. Akubaeva, Zh.I. Sagintaeva, S.T. Edil’baeva, Sh.B. Kasenova, S.Zh.
Davrenbekov, Zh.S. Bekturganov, 2007, published in Zhurnal Neorganicheskoi Khimii, 2007, Vol. 52, No. 9, pp. 1433–1435. 相似文献
12.
T. V. Magdesieva A. V. Dolganov P. M. Polestchuk A. V. Yakimanskii M. Ya. Goikhman I. V. Podeshvo V. V. Kudryavtsev 《Russian Chemical Bulletin》2007,56(7):1380-1389
Structural reorganization of polyamide (PA) and low-molecular-weight CuI and CuII complexes with biquinolyl (biQ) ligands during their mutual redox transformations in solution was studied using the electrochemical
methods (cyclic voltammetry and preparative electrolysis) and quantum chemical DFT calculations. The influence of electronic
factors and geometry distortions in the complexes on the ionization energy on going from CuI to CuII was evaluated in comparison. The catalytically active form of the [CuI(PA)L2]BF4 complex can be synthesized in situ from the stable tetrahedral complex [CuI(PA)2]BF4 by the series of successive redox transitions CuI → CuII → CuI accompanied by the loss of one biQ-containing macroligand.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1331–1340, July, 2007. 相似文献
13.
The kinetic and mechanistic studies of HgII catalyzed exchange of coordinated cyanide in hexacyanoferrate(II) by pyrazine (Pz) were monitored by following the appearance
of the yellow complex [Fe(CN)5Pz]3− at 440 nm corresponding to metal ligand charge transfer (MLCT) transitions at temp=25.0±0.1 °C, pH=2.5±0.02 and ionic strength,
I=0.1 m (KNO3). The effect of pH, ionic strength and the concentrations of [Fe(CN)6]4− and Pz on the rate of reaction were also studied and explained. To investigate the dependency of catalytic activity of HgII, the initial rates were determined at several concentrations of HgII, keeping the concentration of other reactants constant. The kinetic observations suggest that the substitution follows an
interchange dissociative (Id) mechanism and proceeds via formation of a solvent-bound intermediate. The repetitive spectral scan is also provided as evidence for the exchange of
cyanide ions by pyrazine in [Fe(CN)6]4−. Activation parameters have also been evaluated and provided support for the proposed mechanistic scheme. 相似文献
14.
Adrian Topolski Monika Lipiska Przemysaw Kita Joanna Winiewska 《Transition Metal Chemistry》2008,33(7):843-847
The formation of CuII–Br–FeIII-type heterobimetallic complexes was observed spectrophotometrically, given the non-additivity of the spectra from the copper(II)
and iron(III) complexes. The kinetics of the oxidation of promazine radical (ptz+•) to promazine 5-oxide, by iron(III) bromides, copper(II) bromides, and a mixture of these complexes in acidic aqueous solutions,
have been studied using UV–Vis spectroscopy at I = 1.0 M (H+, Cu2+, Fe3+, Br−) and T = 318 K. Copper(II) inhibits the oxidation of the promazine radical to promazine sulfoxide using iron(III) complexes. A rate
retardation effect, characterized by the dependence of the pseudo second-order rate constant (k
II) on the copper(II) concentration k
II = a/(1 + b[CuII]), can be rationalized as a result of CuII–Br–FeIII-type heterobimetallic complex formation. 相似文献
15.
De Stefano C Milea D Pettignano A Sammartano S 《Analytical and bioanalytical chemistry》2003,376(7):1030-1040
The acid–base properties of phytic acid [myo-inositol 1,2,3,4,5,6-hexakis(dihydrogen phosphate)] (H12Phy; Phy12–=phytate anion) were studied in aqueous solution by potentiometric measurements ([H+]-glass electrode) in lithium and potassium chloride aqueous media at different ionic strengths (0<I mol L–13) and at t=25 °C. The protonation of phytate proved strongly dependent on both ionic medium and ionic strength. The protonation constants obtained in alkali metal chlorides are considerably lower than the corresponding ones obtained in a previous paper in tetraethylammonium iodide (Et4NI; e.g., at I=0.5 mol L–1, logK3H=11.7, 8.0, 9.1, and 9.1 in Et4NI, LiCl, NaCl and KCl, respectively; the protonation constants in Et4NI and NaCl were already reported), owing to the strong interactions occurring between the phytate and alkaline cations present in the background salt. We explained this in terms of complex formation between phytate and alkali metal ions. Experimental evidence allows us to consider the formation of 13 mixed proton–metal–ligand complexes, MjHiPhy(12–i–j)–, (M+=Li+, Na+, K+), with j7 and i6, in the range 2.5pH10 (some measurements, at low ionic strength, were extended to pH=11). In particular, all the species formed are negatively charged: i+j–12=–5, –6. Very high formation percentages of M+–phytate species are observed in all the pH ranges investigated. The stability of alkali metal complexes follows the trend Li+Na+K+. Some measurements were also performed at constant ionic strength (I=0.5 mol L–1), using different mixtures of Et4NI and alkali metal chlorides, in order to confirm the formation of hypothesized and calculated metal–proton–ligand complex species and to obtain conditional protonation constants in these multi-component ionic media.Presented at SIMEC–02, Santiago de Compostela, 2–6 June 2002 相似文献
16.
D. V. Konarev S. S. Khasanov D. V. Lopatin V. V. Rodaev R. N. Lyubovskaya 《Russian Chemical Bulletin》2007,56(11):2145-2161
A series of complexes of fullerenes C60 and C70 with metal dithiocarbamates {MII(R2dtc)2}·Cm (m = 60 or 70) and metal dithiocarbamates coordinated to nitrogen-containing ligands (L), {MII(R2dtc)2)x·L}·C60 (x = 1 or 2), where M = Cu, Zn, Cd, Hg, Mn, or Fe, R = Me, Et, Prn, Pri, or Bun, L is 1,4-diazabicyclo[2.2.2]octane (DABCO), N,N′-dimethylpiperazine, or hexamethylenetetramine, were synthesized. The shape of dithiocarbamate molecules is sterically compatible
with the spherical shape of C60, resulting in an efficient interaction between their π systems. The resulting compounds are characterized by a layered or
three-dimensional packing of the fullerene molecules. In the C60 complexes, iron(II) and manganese(II) dithiocarbamates exist in the high-spin states (S = 2 and 5/2). The magnetic susceptibility of {MII(Et2dtc)2}2·Cm (M = Fe or Mn, m = 60 or 70) in the temperature range of 200–300 K is described by the Curie-Weiss law with Θ = −250 and −96 K and with maxima
at 110 and 46 K, respectively, which is indicative of a strong antiferromagnetic spin coupling between MII. The Weiss constants for the [{MII(Et2dtc)2}2·DABCO]·C60·(DABCO)2 complexes (M = Fe or Mn) are 1.7 and 0.3 K, respectively. The magnetic moments of the complexes containing Fe and Mn dithiocarbamates
slightly increase at temperatures below 50 and 35 K, respectively, which is evidence of the ferromagnetic spin coupling between
MII in {MII(Et2dtc)2}2·DABCO. Single crystals of the complexes exhibit low dark conductivity (10−10–10−11 S cm−1). The visible light irradiation of these crystals leads to an increase in the photocurrent by two–three orders of magnitude.
The photogeneration of free charge carriers in the complexes occurs both due to the photoexcitation of metal dithiocarbamate
(CuII(Et2dtc)2) and through the charge transfer from metal dithiocarbamate (MII(Et2dtc)2, M = Zn or Cd) to C60.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2072–2087, November, 2007. 相似文献
17.
L. G. Bruk S. N. Gorodskii A. V. Zeigarnik R. E. Valdés-Peréz O. N. Temkin 《Russian Chemical Bulletin》1999,48(5):873-880
Formal and informal methods for advancing hypotheses on mechanisms were used in a study of the oxidative carbonylation of
phenylacetylene to methyl phenylpropiolate catalyzed by the PdCl2−CuCl−CuCl2 system. The hypotheses remaining after discrimination and consistent with all experimental data include the steps of formation
of the CuI alkynyl complex, transfer of the phenylethynyl group from CuI to PdII, insertion of carbon monoxide into a Pd−C or Pd−OMe bond of the PdII σ-alkynyl complex. Comparison of the formal and informal methods for advancing hypotheses confirmed a higher effeciency of
the first method.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 882–889, May, 1999. 相似文献
18.
J. Lubkowski A. Bujewski J. Szychlinski M. Walewski J. Blazejowski 《Journal of Thermal Analysis and Calorimetry》1992,38(9):2221-2227
Several complex salts of general formula [MII(dipy)3]MIVCl6 or [MII(phen)3]MIVCl6 (whereM
II=Ru, Fe, Ni andM
IV=Sn, Pt) were synthetized and subjected to thermal analyses. Heating of these derivatives leads to the release of organic fragments and chlorine, which are often involved in oxidation processes. The residues comprise metal oxides or pure metals (e.g. Pt). Differences in the structures and features of the ligand molecules, revealed on the basis of quantum-chemistry calculations, account qualitatively for the differences in behaviour and stability of the complex compounds studied.This work was financed by the Polish State Committee for Scientific Research (KBN) under grant 2 0679 91 01 (contract no. 1156/2/91). 相似文献
19.
Synthesis of new bimetallic water-soluble complexes [C12H23N4O7CoCu]5H2O · Cl2 (2), [C12H23N4O7CoNi]5H2O · Cl2 (3) and [C12H23N4O7CoMn]5H2O · Cl2 (4) has been achieved by reaction of the CoIII complex [C12H21N4O6Co]5H2O (1), with transition metal ions. Various physico-chemical techniques: elemental analysis, i.r., u.v.–vis., e.p.r,1H-, 13C- and 2D-n.m.r, spectroscopy, electrochemistry and molar conductance measurements were employed to characterize the complexes.
The interaction of the monometallic complex (1) and bimetallic complexes (2–4) with calf thymus DNA have been carried out by u.v.–vis. titration, cyclic voltammetry (c.v.) and viscosity measurements.
The intrinsic binding constant Kb of the complexes has been calculated. The absorption spectra of complexes exhibit a red shift with an overall ‘hyperchromic
effect’ in the presence of CT-DNA. The binding affinity of the bimetallic complexes to calf thymus DNA is twofold in comparison
with complex (1). The intrinsic binding constant value Kb of complex (1) was found to be 1.2 × 103 M−1, while the Kbvalue of complexes (2–4) were of the order of 1.4 × 103, 2.2 × 103 and 2.1 × 103 M−1, respectively. The Kb values are close to the border between classical and non-classical intercalation that indicates that the binding mode may
be electrostatic, probably with covalent preference in bimetallic complexes. The electrochemical behavior of complexes (1–4) was studied in H2O and displays quasireversible CoII/CoI, CuII/CuI, NiII/NiI and MnII/MnIredox couples. The voltammetric studies of the complexes in the absence and in the presence of DNA exhibit a shift in the
formal potential E0 and ratio of cathodic to anodic peak currents ipa/ipc, indicating binding of the complexes to calf thymus DNA. The viscosity of DNA decreases with increasing concentration of
the complex, suggesting that complexes (2–4) bind to calf thymus DNA by electrostatic association with covalent preference. 相似文献
20.
O. A. Plyusnina V. A. Emel’yanov I. A. Baidina I. V. Korol’kov S. A. Gromilov 《Journal of Structural Chemistry》2007,48(1):114-121
Double complex [RuNO(NH3)4OH][PtCl4] (I) and [RuNO(NH3)4OH][PdCl4] (II) salts have been prepared and explored with TGA, IR spectroscopy, powder and single crystals X-ray diffraction. Crystal phases
of I and II are isostructural (space group Cmc21) and have the following crystal chemical characteristics: a = 8.106 Å, b = 18.190(3) Å, c = 8.097 Å, V = 1194.0 Å3, Z = 4, ρcalc = 3.077 g/cm3 (I), and a = 8.116 Å, b = 18.135 Å, c = 8.062 Å, V = 1186.5 Å3, Z = 4, ρcalc = 2.600 g/cm3 (II). The product of thermal decomposition of I in inert and hydrogen atmospheres is a substitution solid solution Pt0.5Ru0.5 with the parameter of the FCC unit cell a = 3.856(3) Å. Thermolysis of II affords two-phase mixtures of limited solid solutions of the metals featuring Ru-based HCP and Pd-based FCC cells.
__________
Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No.1, pp.114–121, January–February, 2007. 相似文献