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《Polyhedron》2007,26(9-11):1997-2007
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A series of novel calix[4]arene-based Mannich (5 and 6) and Schiff base (9–11) receptors have been synthesized and characterized by various analytical techniques. Competitive two-phase extraction experiments of these novel calix[4]arene amine- and imine-containing derivatives revealed a strong affinity for dichromate anions . The protonated alkylinium form of 5, 6 and 9–11 proved to be effective extractants for transferring the dichromate anions from an aqueous into an organic phase. Moreover, the extraction of dichromate anions by 5 and 9 in the presence of competitive anions such as F?, Cl?, Br?, , , and showed that 5 and 9 could be selective anion receptors for dichromate anions in the presence of those anions. 相似文献
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Dioxygen affinities and catalytic oxidation performance of cobalt(Ⅱ) hydroxamates with benzo-15-crown-5 pendants 总被引:1,自引:0,他引:1
Hong Bo Li Chuan Qin Wen Bing Yang Xiao Ping Hu Sheng Ying Qin 《中国化学快报》2007,18(1):103-106
The oxygenation constants(Ko_2)of cobalt(Ⅱ)hydroxamates(CoL_2~1-CoL_2~3)with benzo-15-crown-5(B15C5)pendants were measured over the range of-5 to 20℃,and the values of thermodynamic parameters(ΔH~0 andΔS~0)were calculated based on these(No_2)values.Meanwhile,these crowned complexes were employed to the oxidation for p-xylene to p-toluic acid with air at 110Δunder normal atmospheric pressure.The effects of B15C5 pendant and the length of chain bonded to B15C5 in these complexes on the O_2-binding capabilities and oxidation for p-xylene were investigated with the comparison of crown-free analogues CoL_2~4. 相似文献
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《Polyhedron》2007,26(9-11):1830-1834
The use of 2-pyridyloximate(-1) ligands, (py)C(R)NO− [R = H, Ph, 2-pyridyl (py)] in cobalt and nickel(II) chemistry has been investigated and led to four families of clusters. A representative member of each family, namely (1), (2), [Ni9(OH)4{(py)CHNO}10(H2O)8]{N(CN)2}3(ClO4) [3{N(CN)2}3(ClO4)] and [Ni4(O2CMe)4{(py)C(ph)NO}4(MeOH)2] (4) is briefly structurally and magnetically described. 相似文献
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《The Journal of chemical thermodynamics》2007,39(6):888-892
Calcium titanofluoride CaTiF5(s) was prepared by solid-state reaction of CaF2(s) with TiF3(s) and characterized by X-ray diffraction method. The standard molar isobaric heat capacity of CaTiF5(s) was determined by a power compensated differential scanning calorimeter in the temperature from 230 K to 710 K. A solid-state galvanic cell with CaF2 as electrolyte was used to determine the standard molar Gibbs energy of formation of CaTiF5 in the temperature range from 803 K to 1005 K. The galvanic cell can be depicted as:The second law analysis of present data were carried out to derive the standard entropy and the enthalpy of formation and the values derived are 68.7 J · K−1 · mol−1 and −2848.4 kJ · mol−1, respectively. 相似文献
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Sulata Kumari Sahu Rajesh Ganesan T. Gnanasekaran 《The Journal of chemical thermodynamics》2010,42(1):1-7
Standard molar Gibbs free energy of formation of ternary oxides Pb5CrO8(s), Pb2CrO5(s), and PbCrO4(s) were determined by measuring equilibrium oxygen partial pressures over relevant phase fields using manometry and solid oxide electrolyte based emf methods and are given by: 相似文献
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《Fluid Phase Equilibria》2006,244(2):117-127
The electrolyte–NRTL model used in a previous work (B. Messnaoui, T. Bounahmidi, Fluid Phase Equilibr. 237(1–2) (2005) 77–85), was extended for modeling of α-hemihydrate and gypsum solubilities in the complex system Ca2+–H+–SO42−–HSO4−–H2PO4−–H3PO4–H2O, at wide range of temperature and P2O5 concentration. The chemical equilibrium constant was evaluated as function of temperature according to the Gibbs–Helmholtz equation. The temperature dependence was taken into account in the expression of the standard state heat capacity of ionic, molecular and cristalline salts species. The standard-state heat capacity of Ca2+at 298.15 K is calculated to be 27.30 J mol−1 K−1. It is also shown that the experimental data agree with the predicted values of gypsum and anhydrite solubilities in water, at high temperature, by using only the values of parameters , which were calculated, at 298.15 K from data of gypsum solubilities in phosphoric acid solutions. 相似文献
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