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1.
I. Lapides N. Lahav K. H. Michaelian S. Yariv 《Journal of Thermal Analysis and Calorimetry》1997,49(3):1423-1432
Intercalation complexes of kaolinite with a series of alkali halides (NaCl (trace amounts), KCl, RbCl, CsCl, NaBr, KBr, CsBr, Kl, Rbl and Csl) were obtained by a thermal solid state reaction between the kaolinite-dimethylsulfoxide intercalation complex and the appropriate alkali halide. The ground mixtures (11 weight ratio) were pressed into disks that were gradually heated up to 250 °C for different times. X-ray diffractograms of the disks were recorded after each thermal treatment. At the end of the thermal treatment the disks were ground and basal spacings of the powders obtained. As a result of thermal treatment, alkali halide ions diffuse into the interlayers, replacing the intercalated dimethylsulfoxide molecules. Such a replacement may take place only if the thermal diffusion of the penetrating species is faster than the evolution of the intercalated organic molecule. With increasing temperature the intercalated salt diffused outside the interlayer space or underwent a thermal hydrolysis which resulted in the evolution of hydrogen halides from the interlayer space. Consequently, the amounts of intercalation complexes decreased at elevated temperatures. 相似文献
2.
Theoretical study on the complexation of bambus[6]uril with the chloride, bromide, and iodide anions
Petr Toman Emanuel Makrlík Petr Vaňura 《Monatshefte für Chemie / Chemical Monthly》2011,286(1):881-884
Abstract
By using quantum mechanical DFT calculations, the most probable structures of the bambus[6]uril·Cl−, bambus[6]uril·Br−, and bambus[6]uril·I− anionic complex species were derived. In these three complexes, each of the considered univalent halide anions, included in the center of the macrocyclic cavity, is bound by 12 weak C–H⋯X− (X− = Cl−, Br−, I−) hydrogen bonds between methine hydrogen atoms on the convex face of the glycoluril units and the respective anion. The lengths of the C–H⋯X− hydrogen bonds increase in the order Cl− < Br− < I−. 相似文献3.
Akahoshi N Ishizaki I Naya M Maekawa T Yamazoe S Horiuchi T Kajimura M Ohashi Y Suematsu M Ishii I 《Analytical and bioanalytical chemistry》2012,402(5):1859-1864
In vivo imaging of reactive small molecule metabolites with high spatial resolution and specificity could give clues to understanding
pathophysiology of various diseases. We herein applied time of flight-secondary ion mass spectrometry (TOF-SIMS) to newly
developed silver-deposited plates that were stamped on mouse tissues, and succeeded in visualization of halide (Cl−, Br−, and I−) and pseudohalide thiocyanate (SCN−) anions, a class of substrates for neutrophils/eosinophil peroxidases to produce hypohalous acids (HOX/OX− mixture; X: (pseudo)halides), as well as hydrogen sulfide (H2S). Forty-micrometer frozen mouse kidney sections on cover glasses were attached to 37 °C preheated silver-deposited plates
and incubated at −10 °C for 1 h. After sputter cleaning to remove surface contaminants, the plates were analyzed by TOF-SIMS
to identify distribution of Br−, AgBr2−, I−, AgI2−, SCN−, as well as S2− and AgS− as products of tissue-derived H2S. Br−, AgBr2−, I−, and SCN− anions were mainly distributed in core regions including the inner medulla and inner stripe of the outer medulla (except
for I−), rather than outer regions such as the cortex and outer stripe of the outer medulla. AgI2− anion was spread over the whole kidney, although its levels were relatively low. In contrast, S2− and AgS− anions were mainly present in the outer regions. To our knowledge, this is the first imaging study to reveal the distribution
of (pseudo)halides and H2S in animal tissue sections. 相似文献
4.
A. N. Sidorov 《Chemistry of Heterocyclic Compounds》1981,17(1):81-83
It was observed that the reaction of acridine with hydrogen halides under heterogeneous conditions proceeds in two steps: An acridinium salt is formed in the first step, while a complex of the salt with hydrogen halide molecules is formed in the second step. The formation of a complex leads to substantial changes in the region of the stretching vibrations of NH+ bonds, and this makes it possible to propose the direct participation of these bonds in complexing. The band of the stretching vibrations of NH+ bonds of the acridinium ion has a complex structure that changes markedly as a function of the sort of halogen ion and replacement of hydrogen by deuterium and in the case of complexing with the hydrogen halide. It is proposed that the structure of this band is due to Fermi resonance.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 99–101, January, 1981. 相似文献
5.
Tin halide perovskites are potential alternatives of lead halide perovskites. However, the easy oxidation of Sn2+ to Sn4+ brings in a challenge. Recently, layered two-dimensional hybrid tin halide perovskites have been shown to partially resist the oxidation process because of the presence of hydrophobic organic molecules. Consequently, such layered hybrid perovskites are being explored for optoelectronic applications. The optical properties of layered tin halide perovskites depend on the interlayer separation and the dielectric mismatch between the organic and inorganic layers. Intercalation (insertion) of a molecular species between the layers modifies the interlayer interactions affecting the optical properties of layered hybrid perovskites. We investigated the effect of hexafluorobenzene (HFB) intercalation in phenethylammonium tin iodide [(PEA)2SnI4] using temperature-dependent (6 K to 300 K) photoluminescence (PL). HFB intercalation increases the bandgap. A strong PL quenching is observed in pristine (PEA)2SnI4 below 150 K, probably because of the presence of non-emissive states. HFB intercalation suppresses the influence of such non-emissive states resulting in an increase in PL intensity at the cryogenic temperatures. Our results highlight that a simple molecular intercalation (non-covalent interaction) into layered hybrid perovskites can significantly tailor the electronic and optical properties. 相似文献
6.
Yan-Hong Qiao Hai Lin Hua-Kuan Lin 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(3-4):211-215
Hydrazone-based receptor containing electron-withdrawing chromogenic substituents 1,10-phenanthroline-2,9-di-carboxaldehydic-(2,4-dinitrophenyl)-hydrazone
(1) has been synthesized. The interaction with different anions via hydrogen bonding was demonstrated by UV-Vis absorption spectroscopy
to give a purple 1:1 complexes in DMSO, whose association constant decreases in line with the following order of the studied
anions (AcO− > F− > H2PO4
− > OH− >>Cl−∼Br−∼I−). As a naked-eyes colorimetric sensor for anions, the study has a latent application importance.
相似文献
7.
Yunsheng Ding Xiaomin Zhang Renyan Xiong Shuyin Wu Min Zha Haiou Tang 《European Polymer Journal》2008,44(1):24-31
1-Octadecyl-3-methylimidazolium chloride ([C18 mim]Cl) is a kind of imidazolium ionic liquid with high thermal stability. [C18 mim]Cl was used to modify pristine Na-montmorillonite and a series of organo-montmorillonite (OMMT) with different loading levels of 1-octadecyl-3-methylimidazolium cation ([C18 mim]+) were obtained. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) results show that there are different loading levels and aggregative state of [C18 mim]+ in the interlayer of OMMT. The effects of OMMT interlayer micro-circumstances on the PP melting intercalation were studied by XRD and transmission electron microscopy (TEM). Results indicate that the melting intercalation of PP into the interlayer of OMMT is not only related with d-spaces but also has something to do with the interlayer micro-circumstance of OMMT. Based on these facts, three types of interlayer absorption models of [C18 mim]+ in the interlayer of OMMT were conceived. In addition, the aggregative state of [C18 min]+ in the interlayer of OMMT, interlayer polarity and d-spaces of OMMT were discussed. According to these models, we try to illustrate the effect of interlayer micro-circumstance of OMMT on the PP melting intercalation. 相似文献
8.
Annia Galano J. Raúl Alvarez-Idaboy Annik Vivier-Bunge 《Theoretical chemistry accounts》2007,118(3):597-606
Eight cyclopropane derivatives (Δ − R) have been modeled, with R = −H, −CH3, −NH2, −C ≡ CH, −C ≡ CCH3, −OH, −F and −C ≡ N. All geometries have been fully optimized at the MP2/ AUG-cc-pVTZ level of calculations. Natural bond
orbital analyses reveal extra p character (spλ, λ > 3) in the C-C bonds of the cyclopropyl rings. The banana-like σ
CC
bonds in the rings are described in detail. Alkene-like complexes between Δ − R molecules and hydrogen fluoride are identified. These weakly bonded complexes are formed through unconventional hydrogen
bond interactions between the hydrogen atom in the HF molecule and the carbon–carbon bonds in the cyclopropane ring. A topological
analysis of the electronic charge density and its Laplacian has been used to characterize the interactions. The possible relevance
of such complexes in the modeling of substrate–receptor interactions in some anti-AIDS drugs is discussed.
Contribution to the Serafin Fraga Memorial Issue. 相似文献
9.
The corrosion and corrosion inhibition effect of carboxymethyl cellulose (CMC) for mild steel in sulphuric acid medium was
investigated using chemical (weight loss and hydrogen evolution) techniques at 30–60 °C. The effect of addition of halide
ions (Cl−, Br−, and I−) was also studied. It was found that CMC functions as an inhibitor for acid induced corrosion for mild steel. Inhibition
efficiency increases with increase in immersion time but decreases with increase in temperature. Addition of halide ions reveals
that chloride ions (Cl−) antagonize the inhibition process whereas iodide ions (I−) exert synergistic effect on the corrosion inhibition by CMC. Corrosion inhibitive effect was afforded by adsorption of CMC
molecules onto the mild steel surface both in the absence and presence of halide ions which was found to follow Langmuir adsorption
isotherm model. The phenomenon of physical adsorption is proposed from decrease in inhibition efficiency with increase in
temperature. The inhibition mechanism was further corroborated by the values of thermodynamic and kinetic parameters obtained
from the experimental data. 相似文献
10.
G. Duplatre L. M. Al-Shukri A. G. Maddock 《Journal of Radioanalytical and Nuclear Chemistry》1980,60(1):159-172
The rate constants for the reactions of positronium with I
3
−
, Br−, and I− in dimethylsulphoxide (DMSO) and for I
3
−
in water have been determined, and the orthopositronium lifetime variations have been used for studying polyhalide formation
in the (I2+Br−)/DMSO system. It is found that the formation of more than one polyhalide is needed to account for the data. On basis of this
new evidence, previous results in methanol and in DMSO are re-examined. Besides the primary I2X− (X−: halide), I2X
2
2−
complexes have to be invoked. Trial absorption measurements confirm the presence of solvolysis equilibria for I2 in DMSO. Taking these facts into account, much higher, albeit poorly defined, values than previously reported are found for
the I2X− formation constants. The reliable Kc values deduced are 28M−1, 0.57M−1 and 2.5M−1 respectively for I2Cl−, I2Cl
2
2
and I2Br
2
2−
in methanol, and 1.4M−1 and 0.8M−1, respectively for I2Cl
2
2−
and I2Br
2
2−
in DMSO. 相似文献
11.
A. Yu. Timoshkin 《Russian Journal of Inorganic Chemistry》2009,54(1):86-99
The structural and thermodynamic properties of oligomeric anions [M
n
X3n+ 1]− (M = Al, Ga, In; X = F, Cl, Br, I; n = 2, 3, 4) have been obtained by the density functional theory B3LYP method with the LAN2DZ(d) and LAN2DZ(d)+ basis sets.
A wide diversity of structural isomers was found for trimeric fluoride anions M3F10−. Among the trimers, except In3F10−, the most stable is a linear isomer composed of two MX3 molecules coordinated to the MX4− anion. The formation of tetrameric anions M4X13− was demonstrated to be thermodynamically allowed at low temperatures at MX3: X− > 4: 1. The existence of higher oligomers is less probable. The affinity of oligomer halides (MX3)
n
for halide ions increases with an increase in n. The propensity to form oligomeric anions decreases in the series F > Cl ≥ Br > I. The fluoride systems show a tendency to
form structures with CN = 5 and 6, these structures for In being the most stable.
Original Russian Text ? A.Yu. Timoshkin, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 1, pp. 87–100. 相似文献
12.
L. Sánchez J. L. Tirado C. Pérez Vicente J. C. Jumas 《Journal of Solid State Electrochemistry》1998,2(5):328-333
Lithium and sodium have been topotactically inserted in the lattice of TaFe1.25Te3 by electrochemical procedures. The existence of electronically unequivalent sites occupied by tellurium atoms conditions
a two-step insertion process. In each step, the alkali metal ions occupy empty sites in the structure which are coordinated
by tellurium atoms of a different set of sites. The␣thermodynamic and kinetic parameters of Li
x
TaFe1.25Te3 and Na
x
TaFe1.25Te3 have been determined and compared with other inserted binary and ternary chalcogenides. The values of the free energy of
intercalation are less negative than those previously reported for TaTe2 and close to those found for the misfit layer compound (PbS)1.13TaS2. The values of alkali metal ion diffusivity are closer to those reported for the binary telluride, due to the similarities
in the atoms exposed to the interlayer space.
Received: 14 October 1997 / Accepted: 14 November 1997 相似文献
13.
采用一种简便的电化学方法制备了有机阳离子(1-丁基-3-甲基咪唑阳离子,BMIM~+)插层的微米尺寸MoS_2层间化合物,并将其用作镁离子电池正极材料。所制备的MoS_2层间化合物(MoS_2-BMIM~+)具有扩大的层间距(0.98 nm),能有效降低Mg~(2+)的嵌入/脱出势垒,为存储Mg~(2+)提供了更多的活性位点,从而表现出显著提高的充电比容量和良好的倍率性能。MoS_2-BMIM~+在20 mA·g~(-1)电流密度下的充电比容量可达101.93 mAh·g~(-1)(约4倍于初始体相MoS_2)。我们进一步证明了这一方法同样适用于插层1-丁基-1-甲基吡咯烷双阳离子(Pyr~+_(14)),所得化合物的层间距为1.04 nm。 相似文献
14.
The effects of temperature on lithium intercalation into non-graphitized carbonized cloth from various electrolytes have
been studied. The open-circuit potential (o.c.p.) of the intercalates shifts in the negative direction as the temperature
is raised. The average temperature coefficient of the o.c.p. is equal to −0.04 mV·K−1 in the range from −35 to +45 °C. Intercalation-deintercalation kinetics was studied by the galvanostatic technique. It was
shown that this process is quasi-ohmic at room and higher temperatures and has activation-ohmic control at lower temperatures.
The effective activation energy of intercalation-deintercalation is about 20kJ·mol−1. Intercalates are corroded in all electrolytes, the corrosion rate being drastically increased as the temperature is raised.
The apparent activation energy of corrosion is 120–150 kJ·mol−1. The corrosion rate is suggested to be controlled by cathodic reduction of electrolyte components.
Received: 11 April 1997 / Accepted: 8 September 1997 相似文献
15.
This work deals with the interaction between urea and DNA bases (adenine, thymine, guanine, and cytosine). The optimized geometries,
binding energies, and harmonic vibrational frequencies are calculated using the DFT/B3LYP functional combined with the 6–31+G(d,p) basis set. Their interactions are studied aiming to understand more about the nature of the intercalation binding forces
between urea and DNA. Fourteen stable complexes are found on the potential energy surface. The structures are cyclic; they
are stabilized by NH...O/N and CH...O interactions. The binding energies range from −19.9 kJ·mol−1 to −74.0 kJ·mol−1. The obtained formation energies indicate that Urea:G and Urea:C are more favorable than Urea:T and Urea:A. In addition,
the Atoms in Molecules theory is performed to study the hydrogen bonds in the complexes. 相似文献
16.
T. A. Sidorov 《Russian Journal of Inorganic Chemistry》2011,56(12):1957-1966
Considering the structural unit of the rhombohedral BaTiO3 phase in the form of Ti(-O...Ti)6 which was constructed by neutron diffraction data, we revealed an atomic group in the form of a pyramidal complex anion TiO32−. Inspection of the Raman spectra of this phase showed symmetry group C
s
for this complex anion. From the similarity of the Raman spectra of all ferroelectric BaTiO3 phases, we inferred that the orthorhombic phase and tetragonal phase are also built of TiO32− complex anions. In the paraelectric cubic phase, TiO32− complex anions decompose to oxygen ions O2− and Ti2+(O−)2 molecules, which are randomly oriented over 12 possible positions. Average Ti-O distances derived from neutron diffraction
data were used to calculate Ti-O− and Ti=O bond lengths in TiO32− complex anions of the ferroelectric BaTiO3 phases. Two types of Ti-O...Ti bridges were found to exist; they belong to weak and strong intermolecular bonds, which are
similar to weak and strong hydrogen bonds (H-bonds) in ferroelectrics. Weak bonds exist in all of the three ferroelectric
phases; strong bonds are only in the orthorhombic phase and the tetragonal phase. As a result of a low potential barrier height
in strong bonds, an oxygen atom persistently hops from one potential well to an adjacent one, which is responsible for bands
appearing below 100 cm−1 in the Raman spectra of the tetragonal phase and orthorhombic phase. The data obtained on the structure of the ferroelectric
BaTiO3 phases were used to interpret their spontaneous polarization, repolarization, and permittivity. 相似文献
17.
E. T. Denisov 《Russian Chemical Bulletin》1998,47(11):2110-2116
A parabolic model of bimolecular radical reactions was used for analysis of the hydrogen transfer reactions of ketyl radicals:
>C·OH+R1COR2→>C=O+R1R2C·OH. The parameters describing the reactivity of the reagents were calculated from the experimental data. The parameters
that characterize the reactions of ketyl and alkyl radicals as hydrogen donors with olefins and with carbonyl compounds were
obtained: >C·OH+R1CH=CH2→>C=O+R1C·HCH3; >R1CH=CH2+R2C·HCH2R3→R2C·HCH3+R2CH=CHR3. These parameters were used to calculate the activation energies of these transformations. The kinetic parameters of reactions
of hydrogen abstraction by free radicals and molecules (adelhydes, ketones, and quinones) from the C−H and O−H bonds were
compared.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2178–2184, November, 1998. 相似文献
18.
The iron(III) dimeric complex [Fe2(CN)10]4− is reduced to the iron(III)iron(II) species [Fe2(CN)10]5− by iodide ion, the equilibrium constant being strongly dependent upon the nature of the alkali metal cation, reduction being
favoured in the sequence: Cs+>NH
4
+
≥K+>Na+>Li+. The reaction kinetics are autocatalytic in character, the catalytic species being the mixed valence dimer. The rates of
reactions are also strongly catalysed by alkali metal cations, in the same sequence as for the equilibrium constants. The
reaction mechanism involves the formation of I
2
−
as a reactive intermediate which can be oxidised by both [Fe2(CN)10]4− and [Fe2(CN)10]5−. 相似文献
19.
IC Determination of Halide Impurities in Ionic Liquids 总被引:1,自引:0,他引:1
An ion chromatographic (IC) method has been developed for determination of trace levels of halide impurities in various types
of ionic liquids (ILs). The advantage of this method is that all relevant halide species can be measured in a single chromatographic
analysis. Separation of halides was performed on a Dionex AS9-HC column using an eluent consisting of 20 mM NaOH and 10% (v/v) acetonitrile, delivered at 1.5 mL min−1. Using this eluent, fluoride, chloride and bromide were well resolved from each other, but iodide was co-eluted with tetrafluoroborate
(BF4−) present as a counter-anion in tetrafluoroborate-based ILs. The same eluent was also used successfully for the determination
of halides in highly hydrophobic ILs, such as those based on bis-(trifluoromethanesulfonyl)imide (TFSI−) and bis-perfluoroethylsulfonylimide (BETI−). In this case, 50% (v/v) acetonitrile aqueous was needed to dissolve the sample before injection, and this did not adversely affect the separation.
Detection limits in the measured solution were 0.1, 0.2 and 1.0 ppm for chloride, bromide and iodide, respectively, by conductivity
detection, and 0.02 ppm for iodide by UV detection. 相似文献
20.
By ene-reaction of 4-phenyl-1,2,4-triazoline-3,5-dione with double bonds, polar 4-phenyl-1,2,4-triazolidine-3,5-dione (phenyl
urazole) groups are introduced into unpolar matrices. Hydrogen-bond complexes are formed between two amide-like units. The
temperature dependence of complex formation in dilute hydrocarbon medium is obtained from remperature-dependent IR spectra
in the region of the C=O stretching vibration. Results obtained for a low molecular-weight model system are compared with
modified polybutadienes, where the groups are attached statistically along the polymer backbone. The enthalpy and the entropy
of complex formation (ΔH
f
=−28.6 kJ/mol; ΔS
f
=−52 J/mol K−1) obtained for the low molecular-weight model prove a dimeric chelate like complex involving two hydrogen bonds. The lower
equilibrium constants observed for the groups attached to the polymer are related to additional topological constraints emerging
from the polymer backbone. 相似文献