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1.
Fillipe V. Rocha Carolina V. Barra Silmar J. S. Franchi Adelino V. G. Netto Antonio E. Mauro Regina C. G. Frem 《Journal of Thermal Analysis and Calorimetry》2011,106(2):385-389
Four new mononuclear Pd(II) complexes of the type [PdX2(tdmPz)] {X = Cl− (1); Br− (2); I− (3); SCN− (4); tdmPz = 1-thiocarbamoyl-3,5-dimethylpyrazole} have been synthesized and characterized by elemental analysis, IR spectroscopy,
1H and 13C{1H}-NMR experiments. The thermal behavior of the complexes 1–4 has been investigated by means of thermogravimetry (TG) and differential thermal analysis (DTA). From the initial decomposition
temperatures, the thermal stability of the complexes can be ordered in the sequence: 3 < 4 ≡ 2 < 1. The final products of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction. 相似文献
2.
P. Storoniak M. Kabir J. Błażejowski 《Journal of Thermal Analysis and Calorimetry》2008,93(3):727-732
The enthalpies of formation of PbCl4, PbCl5− and PbCl62−, originating from quantum mechanics, have enabled the thermodynamic behaviour of these ions with respect to Cl-detachment
to be assessed. The stability of salts containing PbCl5− and PbCl62− as a function of the dimensions of these anions and complementary cations was studied using an approach combining the Kapustinskii-Yatsimirskii
equation with basic thermochemical relationships.
It was found that hexachloroplumbates of monovalent metal cations will not dissociate into metal chlorides and PbCl4, provided the complementary cations are suitably large in size. Hexachloroplumbates of divalent metal cations have not yet
been synthesised since no known metal cations attain the requisite large size. Such salts will not dissociate if the divalent
metal cations are able to complex suitably large electron-donating ligands. The pentachloroplumbates of both monovalent and
divalent metal cations are unstable, since no known metal cations have appropriately large ionic radii. The approach adopted
appears to be useful for the examination of the thermal behaviour, stability and reactivity of chloroplumbates. 相似文献
3.
A. Yu. Bykov G. A. Razgonyaeva N. N. Mal’tseva K. Yu. Zhizhin N. T. Kuznetsov 《Russian Journal of Inorganic Chemistry》2012,57(4):471-473
A new method of synthesis of the B3H8− anion has been suggested. The method uses the reaction of some metal halides (CuCl, SnCl2, CrCl3, PbF2, PbCl2, PbBr2, and BiCl3) with sodium tetrahydroborate. It is characterized by high (up to quantitative) yields and simplicity of isolation of the
target products ((n-C4H9)4N)[B3H8] and Cs[B3H8]. 相似文献
4.
E. A. Il’inchik R. V. Gulyaev D. A. Svintsitskii K. G. Myakishev V. V. Volkov 《Russian Journal of General Chemistry》2010,80(8):1550-1556
Compounds [Et4N]2B3H8 and CsB3H8 are studied using the ESCA method. The results of analysis of the B1s electron spectra and estimation of the effective charge differences in [Et4N]2B3H8 are compared to the data of theoretical calculations of the B3H8− anion. 相似文献
5.
A. B. Azlarov Kh. M. Polvonov M. K. Askarova S. Tukhtaev 《Russian Journal of Inorganic Chemistry》2011,56(1):124-127
The solubility in the 2Na+,Mg2+‖2Cl−, 2ClO3−-H2O system was studied at 20 and 100°C and the solubility diagrams were plotted. New compounds were not found to form in the
title quaternary reciprocal system. The sodium chloride field was observed to expand with rising temperature. 相似文献
6.
Hui-Jun Won Byambatseren Baigalmaa Jei-Kwon Moon Chong-Hun Jung Kune-Woo Lee Jae-Hyuk Hyun 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(2):525-531
Type 304 stainless steel specimens artificially contaminated with CsCl solution were treated with KOH solution and KNO3 solution, respectively. Cs+ ion removal tests by a Q-switched Nd:YAG laser at 1064 nm at a given fluence of 57.3 J/cm2 were performed. The surface morphology and the relative atomic mole ratio of the specimen surface were investigated by SEM
and EPMA. The order of Cs+ ion removal efficiency of laser was no-treatment < KOH < KNO3 during the 42 shots. From the investigation of XPS peaks around 532.7 and 292.9 eV, KNO3 on a surface of specimen was found to be fully decomposed during the laser irradiation. It was suggested that Cs2O particulates formed by the reaction between the reactive oxygen generated from the nitrate ion and Cs+ ion on the metal surface could be easily suspended. For the KOH system, FeOOH was formed during the laser irradiation and
it changed into Fe2O3. It was also suggested that Cs2O particulates were formed by the reaction between the reactive oxygen generated from the decomposition of K2O and Cs+ ion on the metal surface.. 相似文献
7.
8.
Ab initio quantum-chemical calculations of the complexes XeF 5 + XF 6 ? (X = P, As, Sb, and Bi) were performed with the use of relativistic pseudopotentials for heavy atoms and full-electron basis sets. The chemical bonds were characterized by the parameters of critical points (electron density, its Laplacian, total electron energy, and its kinetic and potential components). It was demonstrated that the interaction between the XeF 5 + cation and the XF 6 ? anion in XeF 5 + XF 6 ? follows a key-lock scheme involving directed interactions of bridging fluorine atoms Fb → Xe and that the structuring function of the lone electron pair of the Xe atom is to compensate the destabilizing electrostatic interaction between the Xe and X atoms bearing excess positive charges. 相似文献
9.
With a second-order Møller–Plesset perturbation theory and Hartree–Fock nuclear magnetic resonance calculations, we investigated the magnetic properties of spin singlet and triplet Li3Al 4 ? clusters. The obtained gauge-independent atomic orbital magnetic shielding tensors confirm the paramagnetism of singlet Li3Al 4 ? and diamagnetism of the triplet. The planar rings composed of four aluminum atoms make the magnetic properties of Li3Al 4 ? clusters versatile. The localized molecular orbital, low symmetry of geometric conformation and narrow gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital are found to correlate with the paramagnetism of singlet Li3Al 4 ? . The origin of the paramagnetism is explained. In triplet Li3Al 4 ? , the two outmost orbitals are degenerate, causing a conversion from the paramagnetism to diamagnetism. 相似文献
10.
Zongxiao Li Chunlan Yuan 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(8):1332-1335
With the help of the kinetic parameters (the rate constant (k
in
k
p) and the apparent activation energy (E
in
E
p) of the oscillatory induction period and oscillation period) of the oscillating reaction using thirteen amino acids, leucine
(Leu), threonine (Thr), arginine (Arg), lysine (Lys), histidine (His), alanine (Ala), glutamine (Glu), glycine (Gly), methionine
(Met), cystine (Cys), tryptophan (Trp), serine (Ser) and tyrosine (Tyr), as organic substrates in amino acid-BrO3−-Mn2+-H2SO4-acetone system, then based on the Oregonator model and the thermodynamics theory on irreversible process, the thermodynamic
function (ΔH
in, ΔG
in, ΔS
in and ΔH
p, ΔG
p, ΔS
p) of these oscillating system are studied. The results indicate the entropy ΔS of these oscillating reaction are negative, thereby it is proved that the oscillating reaction is a noequilibrium system
with dissipation structure in agreement with the character of the oscillating reaction from disorder to order in irreversible
thermodynamics. These are satisfactorily to explain the experimental phenomena. 相似文献
11.
I. V. Fedorova M. G. Kiselev L. P. Safonova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(12):2103-2109
The molecular dynamics simulation method was for the first time used to study the structural and energy parameters of H3PO4, H2PO4−, and (DMFA)H+ (protonated dimethylformamide) in liquid N,N-dimethylformamide. The predominant orientation of the nearest neighbors of H3PO4, H2PO4−, DMFA, and (DMFA)H+ was determined from ranked distribution functions. The most probable structure of H-bonded complexes was obtained. It was
shown that H3PO4 formed H-bonds with two DMFA molecules, and and (DMFA)H+ formed H-bonds with one molecule. The dependence of Coulomb interaction energies on the distance between H3PO4, H2PO4−, (DMFA)H+, and DMFA had the form of damped oscillations, as is characteristic of intermolecular interactions in pure DMFA. The molecular
dynamics simulation of the H2PO4−-(DMFA)H+-DMFA ternary system showed a high probability of the formation of contact ion pairs. 相似文献
12.
The adsorption of Cl−, Br−, and I− ions from their 0.1 M solutions in dimethyl formamide at renewable liquid Hg- and Ga-electrodes was studied under similar
experimental conditions by the differential-capacitance and jet-electrode methods. The data obtained points out to a strong
effect of the metal nature on adsorption parameters and the halogenide-ion surface activity series. The halogenide-ion surface
activity at the Hg-electrode increased in the following sequence: Cl− < Br− < I−; at the Ga-electrode, in the reverse sequence: I− < Br− < Cl−. The results are explained qualitatively in terms of the Andersen-Bockris model. It follows from the obtained data that (1)
the free energy of the metal-halogenide-ion interaction increases in the following sequence: I− < Br− < Cl−; (2) the free energy of the Ga-halogenide-ion interaction exceeds that of the Hg−halogenide-ion interaction; and (3) the difference of the Cl−, Br−, and I− ions interaction with the metals increased significantly when passing from Hg− to Ga-electrode. 相似文献
13.
The adsorption of Cl−, Br−, and I− ions on the renewable liquid In-Ga and Tl-Ga electrodes from 0.1 M solutions in dimethyl formamide (DMF) is investigated
by using the method of differential capacitance measurements. The results are compared with similar data obtained on Hg and
Ga electrodes in DMF and with the corresponding data obtained in acetonitrile (AN). It is shown that, in DMF, the adsorption
parameters and the series of surface activity of halide ions (Hal−) significantly depend on the metal nature. In contrast to Hg electrode, on which the surface activity of halide ions increases
in the series: Cl− < Br− < I−, on In-Ga, as well as on the Ga electrode, it varies in the reverse order: I− < Br− < Cl−, whereas on the Tl-Ga electrode, partially reversed series of surface activity is observed: Br− < I− < Cl−. The results are explained within the framework of Andersen-Bockris model. An analysis of experimental results leads to the
following qualitative conclusions: (1) on the In-Ga and Tl-Ga electrodes, as well as on Ga electrode, free energy of metal-Hal− interaction (
$
\Delta G_{_{M - Hal^ - } }
$
\Delta G_{_{M - Hal^ - } }
) increases in series I− < Br− < Cl−; (2) for Cl−, Br−, and I−,
$
\Delta G_{_{M - Hal^ - } }
$
\Delta G_{_{M - Hal^ - } }
) grows in series Tl-Ga < In-Ga < Ga; (3) an absolute magnitude of $
\Delta G_{_{M - Hal_1^ - } } - \Delta G_{_{M - Hal_2^ - } }
$
\Delta G_{_{M - Hal_1^ - } } - \Delta G_{_{M - Hal_2^ - } }
(Hal1−, and Hal2− are any ions of Cl−, Br−, and I−) increases in series Hg < Tl-Ga < In-Ga < Ga; (4) the metal-DMF chemisorption interaction is much stronger than the metal-AN
interaction and increases in series Tl-Ga < In-Ga < Ga. 相似文献
14.
V. A. Savelova A. F. Popov L. N. Vakhitova T. N. Solomoichenko Yu. S. Sadovskii T. M. Prokop'eva A. V. Skrypka B. V. Panchenko 《Russian Journal of Organic Chemistry》2005,41(12):1773-1781
Nucleophilic reactivity of hydroxide and hydroperoxide ions toward ethyl 4-nitrophenyl ethylphosphonate, diethyl 4-nitrophenyl phosphate, 4-nitrophenyl 4-toluenesulfonate, and 4-nitrophenyl dimethylcarbamate in the system H2O2-KOH was studied in aqueous-alcoholic solutions at 25°C. The rate of reactions of both anions with ethyl 4-nitrophenyl ethylphosphonate, diethyl 4-nitrophenyl phosphate, and 4-nitrophenyl dimethylcarbamate and of hydroxide ion with 4-nitrophenyl 4-toluenesulfonate increases with rise in the fraction of the alcohol in mixtures of water with isopropyl and tert-butyl alcohols, while the reaction rate of hydroperoxide ion with 4-nitrophenyl 4-toluenesulfonate decreases. The rate of reactions of both anions with all the above substrates in mixtures of water with ethylene glycol decreases as the fraction of the latter rises. The apparent rate of the reaction of ethyl 4-nitrophenyl ethylphosphonate with anionic nucleophiles in the system H2O2-HO?-HCO 3 ? in water at pH 8.5 almost does not depend on the concentration of ammonium hydrogen carbonate up to a value of 1 M, and it increases when the NH4HCO3 concentration exceeds 1 M. Mixtures of water with the lower monohydric alcohols were recommended for use as components of H2O2-HO?-HCO 3 ? systems for oxidative decomposition of ecotoxicants. 相似文献
15.
F. Bousmina L. Zayani D. Ben Hassen-Chehimi N. Kbir-Ariguib M. Trabelsi-Ayedi 《Monatshefte für Chemie / Chemical Monthly》2003,134(5):763-768
Summary. The diagram of the ternary system Mg2+/Cl−, SO4
2−–H2O was established at 15°C by means of analytical and conductimetric measurements. Three compounds were found in this diagram,
which are MgSO4·6H2O, MgSO4·7H2O, and MgCl2·6H2O. The solubility field of MgSO4·7H2O is important whereas those of MgSO4·6H2O and MgCl2·6H2O are small. The compositions (mass-%) of the two invariant points determined by the two methods are: MgSO4:MgCl2=2.73:33.80 and MgSO4: MgCl2=3.38:28.91. Both the measured and the calculated isotherm at 15°C have been used for modelling of the diagram Mg2+/Cl−, SO4
2−–H2O between 0 and 35°C. The polythermal invariant point was approximately located between 15 and 10°C.
Corresponding author. E-mail: ariguib@planet.tn
Received October 16, 2002; accepted (revised) December 3, 2002
Published online April 24, 2003
RID="a"
ID="a" Dedicated to Prof. Dr. Heinz Gamsj?ger on the occasion of his 70th birthday 相似文献
16.
17.
Chrisman PA Pitteri SJ Hogan JM McLuckey SA 《Journal of the American Society for Mass Spectrometry》2005,16(7):1020-1030
Multiply-charged peptide cations comprised of two polypeptide chains (designated A and B) bound via a disulfide linkage have been reacted with SO2-* in an electrodynamic ion trap mass spectrometer. These reactions proceed through both proton transfer (without dissociation) and electron transfer (with and without dissociation). Electron transfer reactions are shown to give rise to cleavage along the peptide backbone, loss of neutral molecules, and cleavage of the cystine bond. Disulfide bond cleavage is the preferred dissociation channel and both Chain A (or B)-S* and Chain A (or B)-SH fragment ions are observed, similar to those observed with electron capture dissociation (ECD) of disulfide-bound peptides. Electron transfer without dissociation produces [M + 2H]+* ions, which appear to be less kinetically stable than the proton transfer [M + H]+ product. When subjected to collision-induced dissociation (CID), the [M + 2H]+* ions fragment to give products that were also observed as dissociation products during the electron transfer reaction. However, not all dissociation channels noted in the electron transfer reaction were observed in the CID of the [M + 2H]+* ions. The charge state of the peptide has a significant effect on both the extent of electron transfer dissociation observed and the variety of dissociation products, with higher charge states giving more of each. 相似文献
18.
It has been found that halide ions (Cl–, Br–, and I–) in aqueous solution initiate structural transformation of silver trigonal prisms (20?50 nm in size) in the sequence prism ? disc ? sphere. It has been demonstrated that the change in structure is caused by the formation of poorly soluble silver salts on nanoprisms and occurs by the electrochemical mechanism. The efficiency of the process is dictated by the nature of the halide ion. 相似文献
19.
I. V. Mironov V. Yu. Kharlamova V. V. Kokovkin 《Russian Journal of Inorganic Chemistry》2018,63(1):134-139
Substitution of chloride ions in AuCl 4 ? with ethylenediamine (en) and propylenediamine (tn) is studied by capillary zone electrophoresis at I = 0.05 M and T = 25°C. The substitution constants are determined: AuenCl 2 + + en = Auen 2 3+ + 2Cl–, logK2 = 10.4; AuCl 4 ? + tn = AutnCl 2 + + 2Cl–, logK1 = 16.1; AutnCl 2 + + tn = Autn3+2 + 2Cl–, logK2 = 12.0. 相似文献
20.
The rate constant of CF 3 · recombination (\(k_{(CF_3 )_2 }^M \)) in the isochoric isothermal pyrolysis of trifluoroiodomethane at T = 625–732 K and P = 29–300 Torr was derived from molecular iodine accumulation curves. Using literature data for the high-pressure limit and the results of our measurements, an analytical expression for \(k_{(CF_3 )_2 }^M \) was set up for T = 300–1300 K and any pressure of the buffer gas CF3I. 相似文献