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Solubility in the liquid–solid metastable system Li2SO4 + MgSO4 + Na2SO4 + H2O at T = 263.15 K was studied using the isothermal evaporation method. Based on experimental data, dry-salt phase and water-phase diagrams of the system were plotted. The dry-salt phase diagram of the system includes one three-salt co-saturation point, three metastable solubility isotherm curves, and three crystallization regions corresponding to lithium sulphate monohydrate (Li2SO4·H2O), epsomite (MgSO4·7H2O), and mirabilite (Na2SO4·10H2O). Neither a solid solution nor double salts were found. Based on the extended Harvie–Weare (HW) model and its temperature-dependent equation, the values of the Pitzer parameters β(0), β(1), β(2), and CΦ for Li2SO4, MgSO4, and Na2SO4, the mixed ion-interaction parameters θLi,Na, θLi,Mg, θNa,Mg, ΨLi,Na,SO4, ΨLi,Mg,SO4, and ΨNa,Mg,SO4, and the Debye–Hückel parameter AΦ in the quaternary system at 263.15 K were obtained. The solubility of the quaternary system Li2SO4 + MgSO4 + Na2SO4 + H2O at T = 263.15 K was also calculated. A comparison between the calculated and experimental results shows that the predicted solubility agrees well with experimental data. 相似文献
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在298.15 K下利用等温环境溶解反应热量计测定了离子液体C3MIBF4(四氟硼酸1-甲基-3-丙基咪唑)和C5MIBF4(四氟硼酸1-甲基-3-戊基咪唑)不同浓度水溶液的摩尔溶解焓(ΔsHm). 借助Pitzer电解质溶液理论, 得到了它们的标准摩尔溶解焓 和Pitzer焓参数: 和 , 并计算了表观相对摩尔焓. 根据Glasser理论计算了离子液体晶格能, 进而估算了离子液体C5MIBF4和C3MIBF4中正离子的水化焓分别为-171 kJ•mol-1 (C5MI+)和-207 kJ•mol-1 (C3MI+). 相似文献
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The crystal structure of copper sulfate templated by 2-methylpiperazine, (C5H14N2)[Cu(SO4)2(H2O)4] · H2O, was investigated using single crystal X-ray diffraction data. At room temperature, it crystallises in the monoclinic P21/n space group with the following unit-cell parameters: a = 6.9153(1), b = 23.1295(3), c = 10.4472(1) Å, β = 104.227(1)°, V = 1619.75(4) Å3 and Z = 4. The CuII cation adopts a slightly distorted octahedral geometry, arising from four water molecules and two sulfate tetrahedra leading to the formation of [Cu(SO4)2(H2O)4] units. The structure consists of isolated [Cu(SO4)2(H2O)4]2− anions, 2-methylpiperazinediium cations (C5H14N2)2+ and water molecules connected by a three-dimensional hydrogen-bond network. The thermal decomposition of the precursor, studied by thermogravimetry and temperature-dependent X-ray powder diffraction, proceeds through four stages giving rise to the copper oxide. 相似文献
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在298.15 K下利用等温环境溶解反应热量计测定了离子液体C3MIBF4(四氟硼酸1-甲基-3-丙基咪唑)和C5MIBF4(四氟硼酸1-甲基-3-戊基咪唑)不同浓度水溶液的摩尔溶解焓(ΔsHm). 借助Pitzer电解质溶液理论, 得到了它们的标准摩尔溶解焓 和Pitzer焓参数: 和 , 并计算了表观相对摩尔焓. 根据Glasser理论计算了离子液体晶格能, 进而估算了离子液体C5MIBF4和C3MIBF4中正离子的水化焓分别为-171 kJ•mol-1 (C5MI+)和-207 kJ•mol-1 (C3MI+). 相似文献
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G. R. Dey B. N. Singh Sangita D. Kumar T. N. Das 《Plasma Chemistry and Plasma Processing》2007,27(6):669-678
Atmospheric Pressure Dielectric Barrier Discharge (APDBD) initiated decomposition of CO2 and C6–C9 alkanes (in Ar carrier) with uncoated and TiO2/ZnO coated glass surfaces, and under molecular sieve 10 X packing are presented in this study. Alkanes employed include 2-methylpentane,
cyclohexane, n-hexane, n-heptane, n-octane, n-nonane and their decomposition products studied include C1–C3 hydrocarbons viz. CH4, C2H4, C2H6 and C3H8. Generally the yields of all these C1–C3 products increased with discharge energy, however to a major extent the parent alkane structure controlled the relative concentration
profiles of the individual products. Typically the slopes of the increase in various products yield varied from 0.025 to 0.25 ppm
(v/v) mm V−1. However, in the case of cyclohexane the total yield of methane, ethane and propane were only ∼20% of ethylene yield. Use
of TiO2 as well as TiO2/ZnO coated central glass electrode in the APDBD apparatus showed ∼11% enhancement in degradation efficiency. However, while overall 2-methylpentane decomposition reduced significantly to ∼30%, in case of n-octane its decomposition to the C1–C3 products remained unaffected. On the other hand under molecular sieve 10X packing, yield of CH4 and C2H4 increased significantly in both cases. 相似文献
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Phase equilibria studies of the system K2SO4–MnSO4–H2O published revealed discrepancies between the data presented in the literature regarding the solid phases formed at ambient temperatures. The solubility in the system at 298 K and 313 K was determined. At 298 K, the existence of the double salt K2SO4·3MnSO4·5H2O and of MnSO4·H2O was confirmed. The examinations at 313 K showed the formation of the stable solid phases MnSO4·H2O, K2SO4·2MnSO4, K2SO4·MnSO4·1.5H2O, K2SO4 and the formation of a metastable phase K2SO4·MnSO4·2H2O. 相似文献
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Theoretical studies on the dynamics of the exchange reaction H′ + BrH (ν = 0, j = 0) → H′Br + H are performed on potential energy surface (PES) (Kurosaki et al., private communication) for the ground state using the quasi-classical trajectory method. The cross sections, computed at the collision energies (Ec) of 0.5-2.0 eV, are in good agreement with the earlier quantum wave packet results. The rotational, vibrational, and translational fractions in the total energy and the vibrational distribution for the product molecule are calculated at the same collision-energy range. The results support the repulsive character of the PES. In the considered Ec range, it has little chance to occur in an indirect reaction. The alignment and orientation of the product H′Br are investigated in detail with stereodynamics. The results show that Ec can effect on both the alignment and the orientation of product. 相似文献
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Merlín Rosales Beatriz Alvarado Federico Arrieta Carlos De La Cruz Ángel González Karely Molina Otto Soto Yslamar Salazar 《Polyhedron》2008
The synthesis and solid-state IR, 1H and 31P{1H} NMR spectroscopic characterization of complexes of the type MH(CO)(κ3-OCOR)(PPh3)2 [M = Ru, Os; R = CH3, CH2Cl, C6H5 and CH(CH3)2] are reported in this paper. These compounds were obtained by reaction of the respective cationic complex [MH(CO)(NCMe)2(PPh3)2]BF4 with the sodium salt of the corresponding carboxylic acid in a 1:1 v/v dichloromethane/methanol solution at room temperature. The spectroscopic data of these complexes and some DFT calculations reveal an octahedral geometry with a bidentated carboxylate, two equivalent triphenylphosphines in a mutually trans positions, a linear hydride and a linear carbonyl both in the cis-positions of the coordination sphere. The catalytic results indicate that these complexes are efficient and regioselective precatalysts for the quinoline hydrogenation and for the hydroformylation of 1-hexene, under mild reaction conditions (130 °C and 4 atm H2 and 120 °C and 15 atm H2/CO, respectively). For benzothiophene hydrogenation, the osmium complexes showed low activities whereas the analogous ruthenium complexes were catalytically inactive under somewhat more drastic reaction conditions to those of the quinoline hydrogenation (140 °C and 10 atm H2). 相似文献
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Prakash C. Srivastava Sangeeta Bajpai Roli Lath Rajesh Kumar Vikas Singh Shrinkhala Dwivedi Ray J. Butcher Satoko Hayashi Waro Nakanishi 《Polyhedron》2008
The reaction of organo(heterocyclic)tellurium(IV) derivative: C8H8TeI2(1,3-dihydro-2λ4-benzotellurole-2,2-diyl diiodide) with NH4S2CNC5H10 (ammonium piperidine dithiocarbamate) gives C8H8Te(S2CNC5H10)2 (1) and Te(S2CNC5H10)2 (2) or C8H8TeI(S2CNC5H10) (5) according to the reaction conditions. In such type of metathetical reactions, the formation of 2 is unprecedented and it corresponds to the first Te–C cleaved product. The reaction of 2 with CH3I, yields the oxidative addition product, CH3TeI(S2CNC5H10)2 (8). The formation of 2 is also supported through Quantum Chemical calculations. Another Te–C bond cleaved product TeI2[(C13H10N2S)2] · 4C4H8TeI2 (9) is obtained in the reaction of C4H8TeI2 (1,1,2,3,4,5-hexahydro-1,1-diiodotellurophene) with NH4S2CNHC6H5 (ammonium aniline dithiocarbamate). The reaction of 1,1,2,3,4,5,6-heptahydro-1-iodo-1-(morpholine dithiocarbamato) tellurane [C5H10TeI(S2CNC4H8O)] (10) with 1,10-phenanthroline gives an unusual product C12H8N2 · C4H10INO (11). The structures of the new complexes 2, 8, 9, 10 and 11 have been determined by the X-ray analysis. 相似文献
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Jamie L. Manson Tom Lancaster Stephen J. Blundell Yiming Qiu John Singleton Pinaki Sengupta Francis L. Pratt Jinhee Kang Changhoon Lee Myung-Hwan Whangbo 《Polyhedron》2010
The magnetic properties of α-Cu(dca)2(pyz) were examined by magnetic susceptibility, magnetization, inelastic neutron scattering (INS), muon-spin relaxation (μSR) measurements and by first-principles density functional theoretical (DFT) calculations and quantum Monte Carlo (QMC) simulations. The χ versus T curve shows a broad maximum at 3.5 K, and the data between 2 and 300 K is well described by an S = 1/2 Heisenberg uniform chain model with g = 2.152(1) and J/kB = −5.4(1) K. μSR measurements, conducted down to 0.02 K and as a function of longitudinal magnetic field, show no oscillations in the muon asymmetry function A(t). This evidence, together with the lack of spin wave formation as gleaned from INS data, suggests that no long-range magnetic order takes place in α-Cu(dca)2(pyz) down to the lowest measured temperatures. Electronic structure calculations further show that the spin exchange is significant only along the Cu–pyz–Cu chains, such that α-Cu(dca)2(pyz) can be described by a Heisenberg antiferromagnetic chain model. Further support for this comes from the M versus B curve, which is strongly concave owing to the reduced spin dimensionality. α-Cu(dca)2(pyz) is a molecular analogue of KCuF3 owing to dx2-y2 orbital ordering where nearest-neighbor magnetic orbital planes of the Cu2+ sites are orthogonal in the planes perpendicular to the Cu–pyz–Cu chains. 相似文献
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The new polynuclear heterometal alkoxide clusters Ln2Na8(OCH2CF3)14(THF)6 (Ln = Sm 1, Y 2, Yb 3) have been synthesized by the reaction of anhydrous LnCl3 with 7 equiv. of NaOCH2CF3 in 68–75% yields. Crystal structural analysis revealed clusters 1–3 are isomorphous composed of two cubanes and a double open cubane, with one face of an Ln1Na2O4 open cubane capped by an additional Ln1O2 layer. Clusters 1–3 show extremely high activity for the polymerization of ε-caprolactone (ε-CL) and trimethylene carbonate (TMC). The reactivity is much higher than those found for the monometallic alkoxides lanthanide complexes previously reported. The dependence of catalytic activity on lanthanide metals is observed: Yb ≈ Y < Sm for ε-CL and Yb < Y < Sm for TMC. The polymers obtained with these clusters all show a unimodal molecular weight distribution with moderate molecular weight distributions (Mw/Mn = 1.4–1.7), indicating that clusters 1–3 can really be used as single-component catalysts. The bimetallic cooperation and the coordination–insertion mechanism were proposed. 相似文献
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T. M. Polyanskaya E. A. Ilinchik V. V. Volkov M. K. Drozdova O. P. Yureva G. V. Romanenko 《Journal of Structural Chemistry》2008,49(3):494-503
A novel compound of {[(C6H5)NH]2C=NH(C6H5)}[B(C6H5)4]·C2H5OH is prepared and examined by single crystal X-ray diffraction. Crystal data: C45H44BN3O, M = 653.64, monoclinic, space group P21/c, unit cell parameters: a = 24.375(2) Å, b = 17.5829(15) Å, c = 18.090(1) Å, β = 105.277(2)°, V = 7479.0(11) Å3, Z = 8, d
calc = 1.161 g/cm3, T = 293 K, R
1 = 0.064. The structure contains two crystallographically independent cations, two anions, and two solvate ethanol molecules.
Three types of interactions occur between them: interionic N-H(N)⋯π and N(H)⋯π⋯H(C), π-delocalized system of Ph rings of the
anions, and interaction of ions with ethanol molecules N-H⋯O-H(O)⋯π. The compound is characterized by IR and luminescence
spectra. At room temperature, the emission intensity grows with time of exposure to UV irradiation.
Original Russian Text Copyright ? 2008 by T. M. Polyanskaya, E. A. Il’inchik, V. V. Volkov, M. K. Drozdova, O. P. Yur’eva,
and G. V. Romanenko
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Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 3, pp. 512–521, May–June, 2008. 相似文献
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In this work, the reaction O(1D) + H2 → OH + H has been theoretically studied using the quasiclassical trajectory (QCT) method developed by Han and co-workers. All the quasiclassical trajectory calculations are performed on the DK (Dobbyn and Knowles) potential energy surface (PES). The vector correlation information on the reaction O(1D) + H2 → OH + H has been obtained. It has been demonstrated that the product alignment is sensitive to the reactant vibrational quantum number (v) at collision energy of 19 kcal/mol. Moreover, with increasing the value of v, backward scattering becomes weaker and forward scattering becomes stronger. 相似文献