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1.
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
2.
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
3.
V. V. Sharutin V. S. Senchurin O. K. Sharutina 《Russian Journal of Inorganic Chemistry》2012,57(3):398-401
The complex [(HOCH2)3CNH3] 2 + [HgI4]2? (I) was synthesized by reacting (trioxymethyl)methylammonium iodide with mercury dioide (2: 1 mol/mol) in acetone. X-ray crystallography shows that the complex consists of two types of crystallographically independent [(HOCH2)3CNH3]+ cations and tetrahedral anions [HgI4]2? (IHgI, 106.49(2)°–113.99(4)°; Hg-I, 2.7849(8)-2.8105(8) Å. [(HOCH2)3CNH3]+ cations are linked via hydrogen bonds O…H-N and O-H…N (O…N, 2.84–2.92 Å) to form polymer chains, which are cross-linked with one another via anions (I…H, 2.81, 2.82 Å). 相似文献
4.
The optimal structures and the vibrational frequencies of H-bonded complexes formed from one-two CBr3COOH molecules or the CBr3CO 2 – anion with water molecules are calculated by density functional theory (B3LYP/6-31++G(d,p)). The comparison of the obtained results with the known Raman spectra of the CBr3COOH–H2O and NaCBr3CO 2 – ·H2O solutions (with component molar ratios of ≤1:16) shows that they include stable hydrates: CBr3COOH·H2O and CBr3CO 2 – ·(H2O)6. The first one has a cyclic form, and the second has a cubic globular form. The vibrational band frequencies of the CBr3COOH molecule and the CBr3CO 2 – anion in the spectra of both solutions are almost completely determined by the mutual arrangement of units in these hydrates. 相似文献
5.
V. V. Sharutin I. V. Egorova N. N. Klepikov O. K. Sharutina 《Russian Journal of Inorganic Chemistry》2010,55(7):1103-1106
The complex [Ph3P] 4 + [Bi4I16]4? · 2 Me2C=O (I) was synthesized by the reaction of triphenyl(propyl)phosphonium iodide with bismuth iodide in acetone. The crystal structure of complex I was determined by X-ray crystallography. It contains, in addition to solvent molecules, two types of crystallographically independent tetrahedral tetraphenyl(propyl)phosphonium cations and tetranuclear anions [Bi4I16]4? in a chair conformation with the bismuth atoms being in an octahedral coordination. The Bi-I distances in the anion vary within 2.8768(4)–3.2524(4) Å. 相似文献
6.
T. E. Svinarenko A. B. Vishnikin M. N. Timofeeva 《Russian Journal of Inorganic Chemistry》2008,53(9):1359-1365
Procedures were developed for the synthesis of the guanidinium (Gua) and tetrabutylammonium (TBA) salts of 11-molybdotitano(IV)phosphate heteropolyanion (MTPH) from solutions with the stoichiometric ratio P: Mo = 1: 11 and in excess of titanium(IV) ions, Ti: P ≥ 1.5, at pH 1.85–1.90. MTPH was isolated as the (Gua)5PMo11(TiO)O39 and (TBA)5PMo11(TiO)O39 salts. The composition and formula of MTPH were established by chemical analysis, electronic absorption spectroscopy in the visible region of the oxidized and reduced MTPH forms, IR spectroscopy, and 31P NMR. H5PMo11(TiO)O39, obtained by ion exchange of the Gua salt in an aqueous-organic medium, is a strong pentabasic acid. MTPH reacts with H2O2 to form a peroxo complex with limited stability in an aqueous solution. In aqueous-organic media, the peroxo complex is more stable. In acetonitrile, MTPH persists for several days. 相似文献
7.
van der Rest G Jensen LB Abdel-Azeim S Mourgues P Audier HE 《Journal of the American Society for Mass Spectrometry》2004,15(7):966-971
The reactions of the water solvated ammonia radical cation [NH(3)(+*), H(2)O] with a variety of aldehydes and ketones were investigated. The reactions observed differ from those of low energy aldehydes and ketones radical cations, although electron transfer from the keto compound to ionized ammonia is thermodynamically allowed within the terbody complexes initially formed. The main process yields an ammonia solvated enol with loss of water and an alkene. This process corresponds formally to a McLafferty fragmentation within a complex. With aldehydes, another reaction can take place, namely the transfer of the hydrogen from the CHO group to ammonia, leading to the proton bound dimer of ammonia and water, and to the NH(4)(+) cation. Comparison between the available experimental results leads to the conclusion that the McLafferty fragmentation occurs within the terbody complex initially formed, with no prior ligand exchange, the water molecule acting as a spectator partner. 相似文献
8.
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
9.
B. L. Tumanskii I. V. Stankevich A. V. Nikulin V. V. Bashilov V. I. Sokolov 《Russian Chemical Bulletin》2008,57(8):1627-1629
A paramagnetic compound was detected in the synthesis of a hydride (Me)5C60H with an isolated cyclopentadienyl ring. The EPR spectrum of this compound corresponds to free radical (Me)5C60• with nonequivalent Me-group protons. The structure of the radical was confirmed by quantum chemical calculations.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1597–1599, August, 2008. 相似文献
10.
As part of a mass spectrometric investigation of the binding properties of sulfonamide anion receptors, an atmospheric pressure
chemical ionization mass spectrometric (APCI-MS) method involving direct infusion followed by thermal desorption was employed
for identification of anionic supramolecular complexes in dichloromethane (CH2Cl2). Specifically, the dansylamide derivative of tris(2-aminoethyl)amine (tren) (1), the chiral 1,3-benzenesulfonamide derivatives of (1R,2S)-(+)-cis-1-amino-2-indanol (2), and (R)-(+)-bornylamine, (3), were shown to bind halide and nitrate ions in the presence of (n−Bu)4N+X− (X− = Cl−, NO3−, Br−, I−). Solutions of receptors and anions in CH2Cl2 were combined to form the anionic supramolecular complexes, which were subsequently introduced into the mass spectrometer
via direct infusion followed by thermal desorption. The anionic supramolecular complexes [M+X]−, (M=1–3, X−=Cl−, NO3−, Br−, I−) were observed in negative mode APCI-MS along with the deprotonated receptors [M−H]−. Full ionization energy of the APCI corona pin (4.5 kV) was necessary for obtaining mass spectra with the best signal-to-noise
ratios. 相似文献
11.
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
12.
Huaqiao Tan Zhiming Zhang Ding Liu Yanfei Qi Enbo Wang Yangguang Li 《Journal of Cluster Science》2008,19(3):543-550
A new sandwich polyoxometalate Na4Zn2[Zn2(H2O)10(ZnCl)6(B-α- BiW9O33)2] · 40.5H2O (1) has been obtained in aqueous solution and characterized by IR, UV, element analysis, TG and single-crystal X-ray analysis. Polyoxoanion 1 is composed of a Zn 6 12+ hexagon sandwiched by two [BiW9O33]9? units, which is firstly observed in tungstobismutate. The crystal data for compound 1: Triclinic, space group P–1, a = 15.426(3) Å, b = 15.467(3) Å, c = 15.526(3) Å, α = 74.24(3)°, β = 64.37(3)°, γ = 60.73(3)°, V = 2905.3(1) Å3, Z = 1. 相似文献
13.
Jos Oomens Jeffrey D. Steill 《Journal of the American Society for Mass Spectrometry》2010,21(5):698-706
We present the first infrared spectra of a mass-selected deprotonated peptide anion (AlaAlaAla) and its decarboxylated fragment
anion formed by collision induced dissociation. Spectra are obtained by IRMPD spectroscopy using an FTICR mass spectrometer
in combination with the free electron laser FELIX. Spectra have been recorded over the 800–1800 cm−1 spectral range and compared with density functional theory calculated spectra at the B3LYP/6-31++G(d,p) level for different
isomeric structures. These experiments suggest a carboxylate anion for [M-H]− and an amide deprotonated (amidate) structure for the a
3 fragment anion [M-H-CO2]−. The frequency for the amidate carbonyl stretch occurring around 1555±5 cm−1 has been confirmed by additional spectroscopic studies of the conjugated base of N-methylacetamide, which serves as a simple
model system for the deprotonated amide linkage in a peptide anion. 相似文献
14.
V. N. Belyaev N. L. Lebedeva 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(11):1841-1850
Using the third law of thermodynamics, we found the enthalpy Δr
H
o(0) = 71 ± 7 of the reaction Eu+ + H2O ↔ EuOH+ + H and the binding energies D
0(Eu+-OH) = 423 ± 7 and D
0(Eu-OH) = 389 ± 11 (kJ/mol). To determine the latter, we additionally used the ionization potential I
0(EuOH) = 5.32 ± 0.08 eV found using the Stark intramolecular effect. 相似文献
15.
The resonance parameters σ R + of substituents Y in radical cations YD+· [where D is a π- or n-type center, and Y = MMe3, CH2MMe3 (M = Si, Ge, Sn), C(SiMe3)3] depend on the nature of both Y and D. Using radical cations YD+· (Y = CH2SiMe3, SnMe3) as examples, it was found that the two conjugation parameters, constants σ R + of substituents Y and perturbation energy calculated by the modified molecular orbital perturbation method, are linearly related to each other. The energies of donor and acceptor components of the overall resonance effect of CH2SiMe3 and SnMe3 with respect to radical cation centers D+· were estimated for the first time. The donor energy constituent in YD+· is considerably greater than in neutral DY molecules. 相似文献
16.
V. K. Kochnev O. P. Charkin N. M. Klimenko 《Russian Journal of Inorganic Chemistry》2009,54(7):1114-1126
The transition states and activation barriers h of elementary reactions of addition of the H2 molecule to aluminide clusters Al13, Al 13 ? , Al13H 2 ? , Al13H 4 ? , Si@Al12, Ge@Al12, and LiAl13 were calculated within the B3LYP approximation of the density functional theory using 6–31G* and 6–311+G* basis sets. The barriers h for all diamagnetic clusters were found to be high (~30–40 kcal/mol). The outer-sphere cation Li+ decreases while the endohedral electronegative dopants Si and Ge increase the barrier by a few kcal/mol. The hydrogenation barrier of the neural paramagnetic cluster Al13, which has free valence, decreases to ~20 kcal/mol. The addition of a hydrogen atom or a Cl2 molecule to both paramagnetic and diamagnetic aluminum clusters occurs without a barrier. The first stage of the reaction (addition of H2 to an Al-Al edge) is in all cases the critical stage of aluminide hydrogenation. The barrier h of this reaction is several times higher than the barriers to migration of hydrogen atoms over the metal cage. The migration of H atoms occurs simultaneously with considerable distortions of the Al13 cage even to the extent that it changes its structural motif. The addition of the H2 molecule to the Al@TiAl11 cluster containing the peripheral titanium atom occurs with a small barrier, whereas the barrier to elimination of H2 from the dihydride Al@TiAl11H2 is reduced to ~15 kcal/mol. Based on the calculations, the conclusion was drawn that the elementary reactions of hydrogenation and dehydrogenation for Ti-doped aluminide clusters should occur considerably faster and under milder conditions than for homonuclear aluminides. 相似文献
17.
The high-field 19F and 91Zr NMR method is used to study the hydrolysis and polycondensation of hexafluorozirconate ZrF62− in aqueous and water-peroxide solutions. During hydrolysis in aqueous solutions only ZrF62− and F− ions were observed by NMR, however, in the water-peroxide medium, an intermediate product of hydrolysis ([F5Zr-OO-ZrF5]4− dimer) was detected. The dimer structure is confirmed by 19F and 91Zr NMR. In high fields (19F NMR frequency > 200 MHz), the fluorine exchange between ZrF62− and F− is slow in the 19F NMR scale and has a multisite character. 相似文献
18.
She YM Krokhin O Spicer V Loboda A Garland G Ens W Standing KG Westmore JB 《Journal of the American Society for Mass Spectrometry》2007,18(6):1024-1037
Collisional activation of [M + H](+) parent ions from peptides of n amino acid residues may yield a rearrangement that involves loss of the C-terminal amino acid residue to produce (b(n-1) + H(2)O) daughters. We have studied this reaction by a retrospective examination of the m/z spectra of two collections of data. The first set comprised 398 peptides from coat protein digests of a number of plant viruses by various enzymes, where conditions in the tryptic digests were chosen so as to produce many missed cleavages. In this case, a large effect was observed-323 (b(n-1) + H(2)O) daughter ions (approximately 81%), including 185 (approximately 46%) "strong" decays with ratios (b(n-1) + H(2)O)/(b(n-1)) > 1. The second set comprised 1200 peptides, all from tryptic digests, which were carried out under more stringent conditions, resulting in relatively few missed cleavages. Even here, 190 (b(n-1) + H(2)O) ions (approximately 16%) were observed, including 87 (> 7%) "strong" decays, so the effect is still appreciable. The results suggest that the tendency for (b(n-1) + H(2)O) ion formation is promoted by the protonated side chain of a non-C-terminal basic amino acid residue, in the order arginine > lysine > or = histidine, and that its (non-C-terminal) position is not critical. The results can be interpreted by a mechanism in which hydrogen bonding between the protonated side chain and the (n - 1) carbonyl oxygen facilitates loss of the C-terminal amino acid residue to give a product ion having a carboxyl group at the new C-terminus. 相似文献
19.
Wang CZ Su Y Wang HY Guo YL 《Journal of the American Society for Mass Spectrometry》2011,22(10):1839-1850
When using tetrachloromethane as the reagent gas in gas chromatography-ion trap mass spectrometry equipped with hybrid ionization
source, the cation CCl3+ was generated in high abundance and further gas-phase experiments showed that such an electron-deficient reagent ion CCl3+ could undergo interesting ion–molecule reactions with various volatile organic compounds, which not only present some informative
gas-phase reactions, but also facilitate qualitative analysis of diverse volatile compounds by providing unique mass spectral
data that are characteristic of particular chemical structures. The ion–molecule reactions of the reagent ion CCl3+ with different types of compounds were studied, and results showed that such reactions could give rise to structurally diagnostic
ions, such as [M + CCl3 – HCl]+ for aromatic hydrocarbons, [M – OH]+ for saturated cyclic ether, ketone, and alcoholic compounds, [M – H]+ ion for monoterpenes, M·+ for sesquiterpenes, [M – CH3CO]+ for esters, as well as the further fragment ions. The mechanisms of ion–molecule reactions of aromatic hydrocarbons, aliphatic
ketones and alcoholic compounds with the reagent ion CCl3+ were investigated and proposed according to the information provided by MS/MS experiments and theoretical calculations. Then,
this method was applied to study volatile organic compounds in Dendranthema indicum var. aromaticum and 20 compounds, including monoterpenes and their oxygen-containing derivatives, aromatic hydrocarbon and sesquiterpenes
were identified using such ion–molecule reactions. This study offers a perspective and an alternative tool for the analysis
and identification of various volatile compounds. 相似文献
20.
Yan Li Hui-ling Liu Yan-bo Sun Zhuo Li Xu-ri Huang Chia-chung Sun 《Theoretical chemistry accounts》2009,124(5-6):409
A detailed theoretical study is carried out at the B3LYP/6-311G(d,p) and CCSD(T)/6-311++G(3df,2pd) (single-point) levels as an attempt to investigate the mechanism of the little understand ion–molecule reaction between HCN+ and NH3. Various possible reaction pathways are considered. It is shown that six dissociation products P 1 (NH3 + + HCN), P 2 (NH4 + + CN), P 3 (NH3 + + HNC), P 9 (HCNH+ + NH2) P 10 (NCNH3 + + H), and P 12 (HNCNH2 + + H) are both thermodynamically and kinetically feasible. Among these products, P 1 is the most competitive product with predominant abundance. P 3 and P 9 may be the second feasible products with comparable yields. P 12 may be the least possible product followed by the almost negligible P 2 and P 10 . Because the isomers and transition states involved in the HCN+ + NH3 reaction all lie below the reactant, the title reaction is expected to be rapid, which is consistent with the measured large rate constant in experiment. The title reaction may have a potential relevance in Titan’s atmosphere, where the temperature is very low. Furthermore, our calculated results are compared with the previous experimental findings. 相似文献