【作者】 张样盛；

【导师】 陶长元；

【作者基本信息】 重庆大学 ， 物理化学， 2008， 硕士

【摘要】 全硫碳酸钠在农业、选矿、废水处理、半导体纳米材料的制备等领域有良好的应用前景,但到目前为止,其合成条件还过于苛刻,且产率较低。本文以离子液体作为催化剂通过硫化物（一价金属离子）的水溶液和二硫化碳反应合成全硫碳酸盐,研究了离子液体以及离子液体-微波共同作用对合成反应的影响,探索性地展开了以下几个方面的工作并得到了较好的实验结果。①为了全面的了解全硫碳酸盐的基本物性,实验通过丙酮萃取、乙醇溶解、乙醚置换的方法制备出全硫碳酸钠和全硫碳酸钾晶体。通过对制得晶体的XRD、差热图谱的分析发现,全硫碳酸钠是以Na₂CS₃·3H₂O形式存在,其分解温度为150℃;而全硫碳酸钾是以K₂CS₃·H₂O形式存在。对全硫碳酸钠的红外吸收光谱和其溶液的紫外吸收光谱图分析发现,其水溶液在可见光范围的最大吸收波长为502nm,全硫碳酸根以Π64大共轭键的形式存在。②探讨了一种快速测定全硫碳酸钠溶液浓度的方法。实验利用可见光分光光度法检测Na₂CS₃溶液的浓度,发现其在0.008mol/L～0.03mol/L范围内服从朗伯-比尔定律,其线性方程为A=14.726C,相关系数为0.9998。③研究了时间、温度等因素对全硫碳酸钠产率的影响:1)通过在传统加热下合成全硫碳酸钠,初步探索了合成反应的条件。结果表明,温度为40℃时,反应40min后达到平衡,产率为76.0%。对反应进行动力学分析,发现符合1-1级对峙反应规律, Ea=42.7kJ·mol^-1,Ea’=93.2kJ·mol^-1,Q=-50.5kJ·mol^-1。2)在与传统加热相同的条件下用微波辐射（功率为600W）反应体系时,其产率只有60.5%;功率对产率也有影响,反应时间为15min时,功率为600W时产率相对最大,而反应时间为25min时,500W时产率相对最大。3)在传统加热下以离子液体作为相转移剂,能有效地促进合成反应的进行,当温度为40℃时,加入2mL离子液体（[BMIm]BF₄）,反应35min后达到平衡,产率高达96%,而在微波辐射-离子液体共同作用下产率只有89%。④发现微波对合成反应有抑制作用,而离子液体不仅能作为相转移剂促进反应的进行,而且还具有稳定全硫碳酸根的作用,得到制备全硫碳酸钠的最佳条件是:离子液体[BMIm]BF₄ 2mL、反应温度40℃、反应时间35min,合成产率达到96%。更多还原

【Abstract】 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%.更多还原