Synthesis And Characteristics Of Coordinated Ionic Liquids And The Application Of Desulfurization In Model Oil

Ionic liquids, a sort of green organic solvent and catalyzer, are made from organic cations and inorganic anions, they are liquid below 100℃, so they are called ambient temperature ionic liquids, room temperature melting salts and so on. They are outstanding good solvents for a variety of compounds, and their lack of a measurable vapour pressure makes them a desirable substitute for VOCs. Ionic liquids are attractive solvents as they are non-flammable, have a high thermally stable and charactedstc of low melting point, wide electrochemical window, adjustable acidity, strong solubility, high viscosity and so on.Coordinated ionic liquids are new conpounds on the basis of traditional ionic liquids. They have the same general nature with ionic liquids, but have different preparation methods. A range of novel ionic liquids, named coordinated ionic liquids, has been prepared in this paper.[3(CH₃CH₂)₄NCl·(NH₂)₂CO] was synthesized from urea and tetraethyl ammonium chloride. Its structure was characterized by IR, ¹HNMR, and XRD. The results showed that the IR absorption peak of carbonyl was at 1619.10cm^-1 compared with that of urea was at 1690.72cm^-1, which was due to reaction of urea and tetraethyl ammonium chloride. There was a new peak at 2θ=30.37°in the XRD pattern, and it was found that the range of thermal stability is from room temperature to about 250℃, which is higher than other common organic solvents. [(CH₃CH₂)₄NCl·3C₆H₁₁NO] is one another coordinated ionic liquid synthesized from caprolactam and tetraethyl ammonium chloride and the phase diagram of (CH₃CH₂)₄NCl-C₆H₁₁NO was obtained through measurement of the temperature of liquid line. Its structure was characterized by IR and XRD. The results showed that the IR absorption peak of carbonyl was at 1 619.16cm^-1 compared with that of caprolactam being at 1 658.68cm^-1. A new peak was found at 2θ=14～16°in the XRD pattern and the strongest diffraction peaks was at 2θ=18.45°. The characteristic peaks was at 2θ= 20°corresponding caprolactam disappeared. From the TGA-DTA pattern and phase diagram of the coordinated ionic liquid-[(CH₃CH₂)₄NCl·3C₆H₁₁NO], it is found that the range of thermal stability is from room temperature to about 250℃.The other two coordinated ionic liquids were prepared by mixing appropriate molar ratios of urea and zinc chloride or lithium chloride. The properties of the coordinated ionic liquids were investigated and the phase diagrams of them were obtained. When the molar ratio of urea and zinc chloride is 3:1, the melting point is 17℃and conductivity at 100℃is 7.52×10³Î¼S/cm. When the molar radio of LiCl to urea is 1:3, the melting point is 41℃and conductivity at 100℃is 8.63×10³Î¼S/cm.When the coordinated ionic liquids were uesd in desulfurization of model oil, the effectiveness were higher than tetraethyl ammonium chloride.