The knowledge on the ionic structure of YCl 3 -KCl molten system is of guiding significance for the practical production of yttrium metals and yttrium alloys via molten salt electrolysis using this system as electrolyte. In this paper, the theoretical Raman spectra of the ionic groups which may exist in YCl 3 -KCl molten system are simulated by quantum chemical calculation using Gaussian 09 and GaussView 5.0 programs based on density functional theory (DFT). Then the ionic structures of 20 mol%–60 mol% YCl 3 -KCl molten salt systems are studied by comparing the Raman shift values of the bands in the theoretical Raman spectra of different ionic groups with the experimental spectra of this system. YCl 6 3− , Y 2 Cl 7 − , Y 2 Cl 8 2− and Y 2 Cl 9 3− are thought to exist in the molten system. With the increase of temperature, the relative content of YCl 6 3− ionic groups increases while those of Y 2 Cl 7 − , Y 2 Cl 8 2− and Y 2 Cl 9 3− ionic groups decrease. Moreover, the "lifetime" of all ionic groups decreases within the temperature range of 692–730 °C. Meanwhile, the relative contents of Y 2 Cl 7 − , Y 2 Cl 8 2− and Y 2 Cl 9 3− increase with the increase of YCl 3 content, while that of YCl 6 3− decreases. The wave function analysis of the four ionic groups (YCl 6 3− , Y 2 Cl 7 − , Y 2 Cl 8 2− , and Y 2 Cl 9 3− ) is carried out by Multiwfn program. The net charge in each group, the direction of electron migration during the formation of each group, the sites where electrophilic and nucleophilic reactions are most likely to occur in each ionic group, and the order of bond breaking during chemical reactions for the four groups are obtained. Graphical abstract
A new C 5 H 9 NO·SnCl 2 coordinated ionic liquid (IL) was prepared by reacting N-methyl-pyrrolidone with anhydrous SnCl 2 . Desulfurization of dibenzothiophene (DBT) via extraction and oxidation with C 5 H 9 NO·SnCl 2 IL as extractant, H 2 O 2 and equal mol of CH 3 COOH as oxidants was investigated. The Nernst partition coefficients k N of C 5 H 9 NO·SnCl 2 IL for the DBT in n -octane was above 5.0, showing its excellent extraction ability. During the oxidative desulfurization process, the optimal molar ratio of H 2 O 2 /DBT was six. Sulfur removal of DBT in n -octane was 94.8% in 30 min at 30 °C under the conditions of H 2 O 2 /DBT molar ratio of six and V (IL):V (oil) = 1:3. Moreover, the sulfur removal increased with increasing temperature because of the high reaction rate constant, low viscosity, and high solubility of dibenzothiophene-sulfone in the IL. The kinetics of oxidative desulfurization of DBT was also investigated, and the apparent activation energy was found to be 32.5 kJ/mol. The IL could be recycled six times without a significant decrease in activity.
The separation of aromatic and aliphatic hydrocarbons is one of the most challenging and energy-consuming operations in the petrochemical industry. In this study, a number of N -methylpyrrolidone (NMP)-based coordinated ionic liquids (ILs) with various metal salts were prepared and their separation performances were investigated. Among these coordinated ILs, NMP-0.1Fe(NO 3 ) 3 ·9H 2 O showed high selectivity and was used to separate toluene from n -heptane or cyclohexane. Fourier-transform infrared spectroscopy was used to verify that the synthesis of NMP-0.1Fe(NO 3 ) 3 ·9H 2 O was achieved. The toluene distribution coefficient and selectivity were 0.20 and greater than 70, respectively, for a 10 mol% toluene/ n -heptane system, and 0.20 and 23.5, respectively, for a 20 mol% toluene/cyclohexane system. Changing the extraction temperature had little effect on the separation performance. The effects of the solvent dosage, initial concentrations of system components, and regeneration times were also investigated. Experimental liquid–liquid equilibrium data for the studied ternary systems were correlated with the non-random two-liquid model. The results show that NMP-0.1Fe(NO 3 ) 3 ·9H 2 O has potential industrial applications.
危险品化学品经营许可证（带存储）