| Sodium trithiocarbonate has a perfect application prospect in the fields of agriculture, mineral processing, and wastewater treatment and so on, but so far, preparation condition for sodium trithiocarbonate was harsh and the yield was low. In this paper, trithiocarbonates were synthesized by sulphide solution and carbon disulfide with ionic liquid acted as phase-transfer catalyst. The effect on synthesis reaction of sodium trithiocarbonate of ionic liquid and ionic liquid interacted with microwave irradiation were studied. Some exploratory work was done as follows and satisfactory results were obtained.①To comprehensively understand the properties of sodium trithiocarbonate, crystals of sodium trithiocarbonate and potassium trithiocarbonate were prepared from extraction by acetone, dissolution by alcohol and replacement by ether. It was characterized by infrared absorption spectrum, ultraviolet-visible spectroscopy, XRD spectra and DTA picture. Sodium trithiocarbonate, the decomposition temperature of which was 150℃, existed in the form of Na2CS3·3H2O in crystal, while Potassium trithiocarbonate existed in the form of K2CS3·H2O. It was characterized by infrared absorption spectrum, ultraviolet-visible spectroscopy, the results indicated that trithiocarbonate ion was founded exist in the form of large conjugated bond (Π64) in solution and the maximum absorbance wavelength of Na2CS3 solution was 502nm.②A method of quick detecting concentration of Na2CS3 was discussed. UV-Vis spectrophotometry was used to detect the concentration of Na2CS3, the results showed that Beer's law is obeyed in the concentration range of 0.008 mol/L and 0.03mol/L. The relationship of absorbance A and aqueous Na2CS3 concentration C is A=14.726C, with correlation coefficient of 0.9996.③The effect of reaction time and temperature on yield of Na2CS3 were studied: 1) The suitable reaction conditions were gained under conventional heating method. The reaction reached its balance after 40min and the yield was up to 76.0% at 40℃, the reaction follows the rule of 1-1 order reversible reaction, Ea=42.7kJ·mol-1, Ea'=93.2kJ·mol-1,and Q=-50.5kJ·mol-1. 2) Compared with conventional heating method, the yield of Na2CS3 was only 60.5% at 600W (microwave power). The power also had effect on the yield of Na2CS3, when the reaction time was 15min, the optimum power was 600W, while the reaction time was 25min, the optimum power was 500W. 3) Ionic liquid, phase transfer catalyst, could efficiently enhance the yield of Na2CS3. With ionic liquid([BMIm]BF4)2ml, at 40℃for 35min, the yield of Na2CS3 was up to 96.0%, while the yield was only 89% in microwave-ionic liquid system.④Microwave inhibited the synthesis of Na2CS3 because of its non-thermal effect, but ionic liquid not only enhanced the reaction but also could keep trithiocarbonate ion stable. Optimum conditions were obtained as follows: the volume of ionic liquid([BMIm]BF4) 2mL at 40℃for 35min, the yield of Na2CS3 was up to 96%.
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