A new molybdophosphate, (NH3CH2CH2NH3)2Mo5O15(HPO4)2 has been synthesized under hydrothermal conditions and structurally characterized by single crystal X ray diffractions. The compound crystallizes in the monoclinic,...A new molybdophosphate, (NH3CH2CH2NH3)2Mo5O15(HPO4)2 has been synthesized under hydrothermal conditions and structurally characterized by single crystal X ray diffractions. The compound crystallizes in the monoclinic, space group C2/c, a=1.7633(2)nm, b=1.00122(11) nm, c=1.37624(13)nm, β=96.974(5)°, V=2.4117(5)nm3, Z=4, Dc=2.853g·cm-3, μ(MoKα)=2.766mm-1, F(000)=1992. The structure contains the isolated polyanions of [Mo5O15(HPO4)2]4- units around which the portonated ethylenediamine ions are pos itioned. By hydrogen bond interactions the polyanions are interconnected to form a three dimensional network. Other characterizations by powder XRD, IR and thermal analysis are also described. CCDC: 206321.展开更多
In this paper we have systematically studied V-L equilibrium in ternary aqueous solutions containingvolatile electrolytes by introducing a ternary interaction term into Edwards generalized molecular thermody-namic mod...In this paper we have systematically studied V-L equilibrium in ternary aqueous solutions containingvolatile electrolytes by introducing a ternary interaction term into Edwards generalized molecular thermody-namic model and optimizing several adjustable parameters.The program PARA9 with flexible functions ofdoing a series of calculations has been developed and carried out on a TQ-16 computer.It can be usedeither for directly calculating the V-L equilibrium or for optimizing the adjustable parameters.For the sys-toms（NH3-CO3-H2O3,NH3-H2S-H2O and NH3-SO2-H2O）satisfactory results have been obtained withrelative mean deviation of 5-10%.Besides,several sets of adjustable parameters and valuable information ofactivity coefficients,equilibrium concentrations of ions and molecules in solutions are obtained.展开更多
Density functional theory was used at the B3LYP/6-311＋＋G（d,p） level of theory to study the hydrates of 2NH3：H2SO4：nH2O for n = 0～4. Neutrals of the most stable clusters, when n = 0 and 1, spontaneously formed a...Density functional theory was used at the B3LYP/6-311＋＋G（d,p） level of theory to study the hydrates of 2NH3：H2SO4：nH2O for n = 0～4. Neutrals of the most stable clusters, when n = 0 and 1, spontaneously formed and were determined to be hydrogen-bonded molecular complexes of monomeric species. Double ions （clusters containing a NH4＋ cation and a HSO4- anion） or even ternary ions （clusters with two NH4＋ cations and one SO42- anion） spontaneously formed in the most stable clusters of 2NH3：H2SO4：nH2O （n = 2, 3, 4）. The energetics of binding and incremental association was also calculated. Double ions are not energetically favorable until 2NH3：H2SO4：2H2O because of the about equal free energies for forming the neutral （the most stable） and double ion （the second stable） isomers. The free energy of incremental association from free H2O and 2NH3：H2SO4：nH2O has a maximum at n = 2 at room temperature with ΔG ≈ –2 kcal/mol. The comparison of incremental association energies between 2NH3：H2SO4：nH2O, NH3：H2SO4：nH2O and H2SO4：nH2O clusters revealed that NH3 plays an important role in the atmospheric particle nucleation.展开更多
文摘A new molybdophosphate, (NH3CH2CH2NH3)2Mo5O15(HPO4)2 has been synthesized under hydrothermal conditions and structurally characterized by single crystal X ray diffractions. The compound crystallizes in the monoclinic, space group C2/c, a=1.7633(2)nm, b=1.00122(11) nm, c=1.37624(13)nm, β=96.974(5)°, V=2.4117(5)nm3, Z=4, Dc=2.853g·cm-3, μ(MoKα)=2.766mm-1, F(000)=1992. The structure contains the isolated polyanions of [Mo5O15(HPO4)2]4- units around which the portonated ethylenediamine ions are pos itioned. By hydrogen bond interactions the polyanions are interconnected to form a three dimensional network. Other characterizations by powder XRD, IR and thermal analysis are also described. CCDC: 206321.
文摘In this paper we have systematically studied V-L equilibrium in ternary aqueous solutions containingvolatile electrolytes by introducing a ternary interaction term into Edwards generalized molecular thermody-namic model and optimizing several adjustable parameters.The program PARA9 with flexible functions ofdoing a series of calculations has been developed and carried out on a TQ-16 computer.It can be usedeither for directly calculating the V-L equilibrium or for optimizing the adjustable parameters.For the sys-toms（NH3-CO3-H2O3,NH3-H2S-H2O and NH3-SO2-H2O）satisfactory results have been obtained withrelative mean deviation of 5-10%.Besides,several sets of adjustable parameters and valuable information ofactivity coefficients,equilibrium concentrations of ions and molecules in solutions are obtained.
基金supported by the National Natural Science Foundation of China (20528706)the China Postdoctoral Science Foundation (20090450385)
文摘Density functional theory was used at the B3LYP/6-311＋＋G（d,p） level of theory to study the hydrates of 2NH3：H2SO4：nH2O for n = 0～4. Neutrals of the most stable clusters, when n = 0 and 1, spontaneously formed and were determined to be hydrogen-bonded molecular complexes of monomeric species. Double ions （clusters containing a NH4＋ cation and a HSO4- anion） or even ternary ions （clusters with two NH4＋ cations and one SO42- anion） spontaneously formed in the most stable clusters of 2NH3：H2SO4：nH2O （n = 2, 3, 4）. The energetics of binding and incremental association was also calculated. Double ions are not energetically favorable until 2NH3：H2SO4：2H2O because of the about equal free energies for forming the neutral （the most stable） and double ion （the second stable） isomers. The free energy of incremental association from free H2O and 2NH3：H2SO4：nH2O has a maximum at n = 2 at room temperature with ΔG ≈ –2 kcal/mol. The comparison of incremental association energies between 2NH3：H2SO4：nH2O, NH3：H2SO4：nH2O and H2SO4：nH2O clusters revealed that NH3 plays an important role in the atmospheric particle nucleation.
