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1.
L. N. Vakhitova A. V. Skrypka K. V. Bogutskaya N. A. Taran A. F. Popov 《Theoretical and Experimental Chemistry》2007,43(6):389-395
The reactivity of hydroxide and peroxide anions with 4-nitrophenyl N,N-dimethylcarbamate in aqueous-alcoholic detergent media
and in “oil in water” microemulsions has been studied. Aqueous-alcoholic solutions of cationic (CTAB) and neutral (Triton
X-100) surface active substances have promise for decomposition of substrates by a nucleophilic mechanism.
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Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 6, pp. 358–363, November–December, 2007. 相似文献
2.
L. N. Vakhitova N. V. Lakhtarenko A. V. Skrypka E. Yu. Kaida N. A. Taran A. F. Popov 《Theoretical and Experimental Chemistry》2011,47(4):225-231
The nucleophilic decomposition of paraoxon (4-nitrophenyl ester of diethylphosphoric acid) by the HOO− anion generated from peroxysolvates of sodium carbamide and carbonate in aqueous, micellar, microemulsion, and water–ethanol
media was studied. Feasibility was demonstrated for the use of solid sources of hydrogen peroxide in decontaminating nucleophilic
systems. 相似文献
3.
L. N. Vakhitova S. V. Zhil’tsova A. V. Skrypka N. G. Razumova N. A. Taran V. A. Savelova A. F. Popov 《Theoretical and Experimental Chemistry》2006,42(5):287-294
The kinetics and mechanism of the catalysis by ammonium hydrogen carbonate oxidation of methyl phenyl sulfide with hydrogen
peroxide has been investigated. Using the classical pseudo-phase model of micellar catalysis, the basic parameters of the
catalytic process have been determined: the binding constants of H2O2, the HCO
4
−
anion, and the substrate to the surface of the micelles, and also the second order rate constants for the oxidation of methyl
phenyl sulfide in the micellar phase.
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Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 5, pp. 281–287, September–October, 2006. 相似文献
4.
Sergey Sladkevich Vitaly Gutkin Ovadia Lev Elena A. Legurova Dzhalil F. Khabibulin Martin A. Fedotov Vladimir Uvarov Tatiana A. Tripol’skaya Petr V. Prikhodchenko 《Journal of Sol-Gel Science and Technology》2009,50(2):229-240
Stable, amorphous potassium peroxystannate nanoparticles of controlled average size—in the range 10–100 nm—and of controlled
hydrogen peroxide content—in the range of 19–30 wt%—were synthesized by hydrogen peroxide induced polymerization in water–potassium
hexahydroxostannate solutions. The sol phase and the precipitate were characterized by vibrational spectroscopies, 119Sn NMR, XPS and XRD using crystalline K2Sn(OH)6 and K2Sn(OOH)6 reference materials. This is the first study to show that peroxocoordination induces polymerization of a main group element.
119Sn NMR studies show that peroxotin coordination and polymerization took place already in the hydrogen peroxide–water phase.
The high abundance of peroxotin bonds revealed by 119Sn MAS NMR, vibrational spectroscopy, and XPS suggests that the particles are predominantly made of peroxo bridged tin networks.
Although the particles are highly stable in the dry phase as well as in alcohol solutions and do not lose hydrogen peroxide
upon storage, they release their stored hydrogen peroxide content by exposure to water. 相似文献
5.
V. V. Poskonin 《Chemistry of Heterocyclic Compounds》2008,44(3):295-300
The special features of the oxidation of furfural by aqueous hydrogen peroxide in the presence of vanadyl sulfate and ethanol
has been studied for the first time. It has been established that this reaction proceeds with the formation of previously
unknown oxidation products of furan compounds, one of which was isolated from the reaction mixture as the ethyl ester. It
was established by spectral methods and qualitative reactions that this product is 5-ethoxycarbonyl-4-hydroxy-3-oxo-2(3H)-furanone.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 386–392, March, 2008. 相似文献
6.
Kim Sung Bae Um Byung Hwan Park Soon Chul 《Applied biochemistry and biotechnology》2001,91(1-9):81-94
The effect of pretreatment reagent and hydrogen peroxide on enzymatic digestibility of oak was investigated to compare pretreatment
performance. Pretreatment reagents used were ammonia, sulfuric acid, and water. These solutions were used without or in combination
with hydrogen peroxide in the percolation reactor. The reaction was carried out at 170°C for the predetermined reaction time.
Ammonia treatment showed the highest delignification but the lowest digestibility and hemicellulose removal among the three
treatments. Acid treatment proved to be a very effective method in terms of hemicellulose recovery and cellulose digestibility.
Hemicellulose recovery was 65–90% and digestibilities were >90% in the range of 0.01–0.2% acid concentration. In both treatments,
hydrogen peroxide had some effect on digestibility but decomposed soluble sugars produced during pretreatment. Unlike ammonia
and acid treatments, hydrogen peroxide in water treatment has a certain effect on hemicellulose recovery as well as delignification.
At 1.6% hydrogen peroxide concentration, both hemicellulose recovery and digestibility were about 90%, which were almost the
same as those of 0.2% sulfuric acid treatment. Also, digestibility was investigated as a function of hemicellulose removal
or delignification. It was found that digestibility was more directly related to hemicellulose removal rather than delignification. 相似文献
7.
Precipitated hardwood lignin (PHL) is a major byproduct in the biomassto-ethanol process. Oxidativecracking of PHL by hydrogen
peroxide in aqueous medium was investigated as a means to produce potentially useful chemicals. The cracking reaction takes
place at moderate temperatures (80–160°C), giving mono-and dicarboxylic acids as the main products. The yields of these products
are in the range of 30–50% of initial lignin. The reaction mechanism and the product distribution are dependent upon the reaction
conditions, especially the pH. The reaction under strong alkaline condition proceeds well even at low reaction temperatures
(80–90°C). Under acidic conditions, higher temperatures (130–160°C) are required to attain the same degrees of cracking. The
reaction patterns of the oxidative cracking reaction involve the cleavage of lignin ring, aryl ether bond, or other linkages
within lignin. By using the findings of this investigation and those of previous work, we have illustrated the reaction pathways
for degradation of PHL under alkaline and acidic conditions. Aldehydes and aromatic acids are interm ediate products in the
oxidative degradation of lignin. However, they were produced only in trace amounts owing to rapid degradation induced by hydrogen
peroxide.
Presented at the 21st Symposium on Biotechnology for Fuels and Chemicals, Fort Collins, CO, May 1999. 相似文献
8.
The Ti–TPyP reagent, i.e. an acidic aqueous solution of the oxo[5,10,15,20-tetra(4-pyridyl)porphyrinato] titanium(IV) complex,
TiO(tpyp), was developed as a highly sensitive and selective spectrophotometric reagent for determination of traces of hydrogen
peroxide. Using this reagent, determination of hydrogen peroxide was performed by flow-injection analysis with a detection
limit of 0.5 pmol per test. The method was actually applied to determination of several constituents of foods, human blood,
and urine mediated by appropriate oxidase enzymes. The reaction specificity of the TiO(tpyp) complex for hydrogen peroxide
was clarified from the viewpoint of the reaction mechanisms and molecular orbitals based on ab initio calculations. The results
provided a well-grounded argument for determination of hydrogen peroxide using the Ti–TPyP reagent experimentally. This review
deals with characterization of the high sensitivity and reaction specificity of the Ti–TPyP reagent for determination of hydrogen
peroxide, to prove its reliability in analytical applications.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
9.
Carbon paste electrodes, modified by Cu2O or CuO, were prepared and tested as sensors for hydrogen peroxide in aqueous solutions. They show a cathodic response to
the analyte ranging from 0.45 to 0.14 mA/cm2 for 1 mmol/L hydrogen peroxide for solutions of pH 5.2 and 7.3, respectively, at a working potential of –0.4 V vs. Ag/AgCl.
The cathodic operation mode used diminishes or excludes the possibility of anodic discharge of contaminants usually present
in biological fluids, and enables the use of the sensors in bioanalytical systems based on enzymes.
Received: 18 April 1997 / Accepted: 24 June 1997 相似文献
10.
In this paper, the interaction between hydrogen peroxide (HP) and water were systemically studied by atom-bond electronegativity
equalization method fused into molecular mechanics (ABEEM/MM) and ab initio method. The results show that the optimized geometries, interaction energies and dipole moments of hydrated HP clusters HP(H2O)
n
(n = 1–6) calculated by ABEEM/MM model are fairly consistent with the MP2/aug-cc-pVTZ//MP2/aug-cc-pVDZ results. The ABEEM/MM
results indicate that n = 4 is the transition state structure from 2D planar structure to 3D network structure. The variations of the average hydrogen
bond length with the increasing number of water molecules given by ABEEM/MM model agree well with those of ab initio studies. Moreover, the radial distribution functions (RDFs) of water molecule around HP in HP aqueous solution have been
analyzed in detail. It can be confirmed that HP is a good proton donor and poor proton acceptor in aqueous solution by analysis
of the RDFs. 相似文献
11.
Electrochemical properties of aniline in 1,2-dichloroethane are investigated by cyclic voltammetry, electrochemical impedance
spectroscopy, and in situ UV-vis spectroelectrochemistry. Aniline is an additive in gasoline, whose antiknock mechanism is
extrapolated on the basis of its electrochemical properties and its reaction with hydrogen peroxide. The experimental results
indicate that for aniline low parent concentration and non-protonic solvents are in favor of producing benzidine by tail-to-tail
coupling of cation radicals, the nature of the reaction between aniline and hydrogen peroxide is in that the proton released
from electrooxidation can interact with hydrogen peroxide. Hydrogen peroxide can reduce the resistance of the electrochemical
reaction and also has an inhibiting effect on the transmission of ion from solution to the electrode surface. The results
offer significant evidence and a new method for studying antiknock mechanism of aromatic amines.
Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 9, pp. 1071–1076.
The text was submitted by the authors in English. 相似文献
12.
13.
A polypyrrole electrode with ferrocene mediator is prepared and its sensitivity to hydrogen peroxide is investigated. The
polypyrrole is deposited upon a 0.5 cm2 Pt plate by the polymerization of pyrrole by scanning the electrode potential between 0.0 and 0.9 V at a scan rate of 50
mV/s. The platinum/polypyrrole-ferrocene (Pt/PPy-Fc) electrode is prepared by adding ferrocene to the coverage medium. The
electrode’s sensitivity to hydrogen peroxide is investigated at room temperature using 0.025 M phosphate buffer at pH 7. The
working potential is 0.7 V, the concentrations of pyrrole and ferrocene are 0.2 M and 10 mM. Polypyrrole was coated on the
electrode surface within 26 cycles.
Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 2, pp. 160–164.
The text was submitted by the authors in English. 相似文献
14.
V. M. Ivanov Ya. I. Shcherbakova V. N. Figurovskaya 《Moscow University Chemistry Bulletin》2011,66(6):340-344
Conditions of formation and the absorption spectra of chrome(III) solutions, obtained by the reduction of chrome(VI) with
sodium sulfite, ascorbic acid, or hydrogen peroxide, were studied. The solutions have a maximum absorption at 410–420 and
560–580 nm, and molar absorption coefficients from 17 to 80. The chromaticity functions of these forms of chrome(VI) were
studied and it was shown, that they are higher in the order of 1–1.5 than molar absorption coefficients. The yellowness is
maximal in all cases. 相似文献
15.
Qing-Guo Zhang Feng Xue Jing Tong Wei Guan Bin Wang 《Journal of solution chemistry》2006,35(3):297-309
In order to test the mole-fraction composition-based models as applied to aqueous solutions of an ionic liquid, the densities
of aqueous 1-methyl-3-butylimidazolium tetrafluoroborate (BMIBF4) were measured using a Westphal balance in the concentration range of about 0.2 to 0.85 mole fraction at temperatures from
283.2 to 323.2 K. Values of the apparent molar volumes of concentrated aqueous BMIBF4 solutions were calculated from these densities and were represented with the Pitzer–Simomson and the Pitzer–Simomson–Clegg
equations. The values of Pitzer–Simomson parameters and Pitzer–Simomson–Clegg parameters were obtained by fitting to experimental
data with small standard deviations. 相似文献
16.
The electrical conductivities of aqueous solutions of quinic acid and its sodium salt were measured from 293.15 to 328.15 K
in steps of 5 K. The molar conductivities of the sodium salt were treated by the Lee–Wheaton equation, in the form of Pethybridge
and Taba, and the Kohlrausch equations. The limiting molar conductivities of the quinate anion were estimated, as well as
the corresponding ionic association constants and standard thermodynamic functions of the ionic association reaction. The
hydrodynamic radius of the quinate anion was calculated from the Walden rule and compared with the van der Waals radius. The
dissociation constant of quinic acid was evaluated from the known value of the limiting molar conductivity of quinic acid
using the conductivity equation of Pethybridge and Taba. The standard thermodynamic functions of the dissociation process,
i.e., the Gibbs energy, enthalpy, entropy and heat capacity, were obtained using the non-empirical procedure given by Clarke
and Glew. The standard thermodynamic functions of dissociation of quinic acid are discussed in terms of solute–solvent interactions
and stabilization of the quinate anion due to hydrogen bonding of the α-hydroxyl group to the carboxyl group. 相似文献
17.
De-Qi Yuan Yuewei Zhao Makoto Fukudome Kahee Fujita 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):125-129
One or two coumarin units were incorporated to the primary face of γ-cyclodextrin (γ-CD), and the resultant coumarin derivatives
were employed to harvest the chemical energy generated in the reaction of bis(trichlorophenyl)oxalate with hydrogen peroxide.
In comparison with the coumarin without CD cavity for molecular recognition, the coumarin–CD conjugates demonstrated much
higher chemiluminescence inetensity, indicating that the CD moiety remarkably improves the chemical energy transfer. 相似文献
18.
ZhuanNiYU XiRong HUANG ShaoFangSONG DanWANG XueMeiLU YueZhongLI YinBoQU PeiJiGAO 《中国化学快报》2003,14(8):836-839
The inhibition of lingninase by hydrogen peroxide in the presence of cationic surfactant CTAB was studied by kinetic speetrophotometdc technique. Results showed that addition of CTAB enhanced the inhibition by H202, but it did not alter the inhibition pattern and the inhibition constant changed little with theco-ncentration of CTAB. Modification of the enzymic protein by the surfactant monomer may be responsible for the above mentioned results. 相似文献
19.
The rate of reaction of Cr(III)L (L=N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetate) with hydrogen peroxide was studied
in aqueous media and was found to yield Cr(VI) over the temperature range of 25–41 °C. The reaction was followed spectrophotometrically
at 396 nm under pseudo-first order conditions with hydrogen peroxide in a large excess. The reaction follows first-order kinetics
in Cr(III). The dependence of the rate constant on hydrogen peroxide concentration is attributed to the formation of an intermediate
between the monohydroxy chromium(III) complex and hydrogen peroxide which decomposes in the rate determining step. At high
hydrogen peroxide concentration, the order is changed from first to zero order.The values of the intramolecular electron transfer
rate constant, the formation constant of the intermediate complex and the activation parameters were calculated. 相似文献
20.
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.
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Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1077–1082, May, 2005. 相似文献