本文研究了Cr^(3+)在1-丁基-3-甲基咪唑硫酸氢盐([BMIM]HSO_4)电解液中的电沉积反应以及添加剂NaOAc对电镀铬的影响.含Cr^(3+)电解液的循环伏安结果表明,Cr(Ⅲ)还原为Cr(Ⅱ)的峰电位是-1.5 V (vs. Pt),峰电位和峰电流均满足Rendle-Sevci...本文研究了Cr^(3+)在1-丁基-3-甲基咪唑硫酸氢盐([BMIM]HSO_4)电解液中的电沉积反应以及添加剂NaOAc对电镀铬的影响.含Cr^(3+)电解液的循环伏安结果表明,Cr(Ⅲ)还原为Cr(Ⅱ)的峰电位是-1.5 V (vs. Pt),峰电位和峰电流均满足Rendle-Sevcik扩散方程,由该方程计算得到Cr^(3+)的扩散系数为1.6×10^(-8)cm^2·s^(-1).铬镀层的X射线衍射和扫描电子显微镜表征结果表明镀层由纳米球状的单质铬颗粒聚集而成,其平均粒径为0.87μm.在电解液中添加NaOAc后,Cr^(3+)的还原峰电位正移了约0.25 V.同时EDS结果表明,在NaOAc的作用下镀层中Cr/O摩尔比由4.48增加至6.28,这说明OAc-有利于单质铬的电沉积.当电解液中NaOAc-[BMIM]HSO_4-CrCl_3-H_2O的摩尔比为0.075:1:0.5:6时,所得的镀层最厚(63μm)与电流效率最高(33.5%).展开更多
在101.32 k Pa下,用改进的Othmer釜测定了含离子液体1-乙基-3-甲基咪唑三氟甲磺酸盐([emim]OTf)的乙酸乙酯-乙腈物系的等压汽液平衡数据;采用NRTL方程对实验数据进行关联,关联效果良好。实验结果表明,加入[emim]OTf后,乙酸乙酯-乙腈二...在101.32 k Pa下,用改进的Othmer釜测定了含离子液体1-乙基-3-甲基咪唑三氟甲磺酸盐([emim]OTf)的乙酸乙酯-乙腈物系的等压汽液平衡数据;采用NRTL方程对实验数据进行关联,关联效果良好。实验结果表明,加入[emim]OTf后,乙酸乙酯-乙腈二组分物系汽液平衡线发生偏离,[emim]OTf含量越高,偏离程度越大;[emim]OTf具有明显的盐析效应,当[emim]·OTf的含量达到5%(x)时,就可消除乙酸乙酯-乙腈物系的共沸点;[emim]OTf可作为乙酸乙酯-乙腈萃取精馏的萃取剂。展开更多
3,4-Dihydropyrimidin-2-(1H)-ones were synthesized in high yields by a one-pot cyclocondensation of aldehyde,1,3-dicarbonyl compound,and urea or thiourea using copper o-toluenesulfonate as a catalyst under solvent-free...3,4-Dihydropyrimidin-2-(1H)-ones were synthesized in high yields by a one-pot cyclocondensation of aldehyde,1,3-dicarbonyl compound,and urea or thiourea using copper o-toluenesulfonate as a catalyst under solvent-free conditions at 90℃.Effects of molar ratio of reactants,amount of catalyst,and reaction temperature on the yields of 3,4-dihydropyrimidin-2-(1H)-ones were investigated.The results showed that at the condition of naldehyde∶n1,3-dicarbonyl compounds∶nurea(or thiourea)=1∶1.2∶1.5,1 mol% catalyst(molar percent of aldehyde),2.0 h at 90℃,the yields of products were 51-96%.After reaction,the catalyst could be reused for four times without distinct loss of catalytic activity.展开更多
文摘本文研究了Cr^(3+)在1-丁基-3-甲基咪唑硫酸氢盐([BMIM]HSO_4)电解液中的电沉积反应以及添加剂NaOAc对电镀铬的影响.含Cr^(3+)电解液的循环伏安结果表明,Cr(Ⅲ)还原为Cr(Ⅱ)的峰电位是-1.5 V (vs. Pt),峰电位和峰电流均满足Rendle-Sevcik扩散方程,由该方程计算得到Cr^(3+)的扩散系数为1.6×10^(-8)cm^2·s^(-1).铬镀层的X射线衍射和扫描电子显微镜表征结果表明镀层由纳米球状的单质铬颗粒聚集而成,其平均粒径为0.87μm.在电解液中添加NaOAc后,Cr^(3+)的还原峰电位正移了约0.25 V.同时EDS结果表明,在NaOAc的作用下镀层中Cr/O摩尔比由4.48增加至6.28,这说明OAc-有利于单质铬的电沉积.当电解液中NaOAc-[BMIM]HSO_4-CrCl_3-H_2O的摩尔比为0.075:1:0.5:6时,所得的镀层最厚(63μm)与电流效率最高(33.5%).
文摘在101.32 k Pa下,用改进的Othmer釜测定了含离子液体1-乙基-3-甲基咪唑三氟甲磺酸盐([emim]OTf)的乙酸乙酯-乙腈物系的等压汽液平衡数据;采用NRTL方程对实验数据进行关联,关联效果良好。实验结果表明,加入[emim]OTf后,乙酸乙酯-乙腈二组分物系汽液平衡线发生偏离,[emim]OTf含量越高,偏离程度越大;[emim]OTf具有明显的盐析效应,当[emim]·OTf的含量达到5%(x)时,就可消除乙酸乙酯-乙腈物系的共沸点;[emim]OTf可作为乙酸乙酯-乙腈萃取精馏的萃取剂。
文摘3,4-Dihydropyrimidin-2-(1H)-ones were synthesized in high yields by a one-pot cyclocondensation of aldehyde,1,3-dicarbonyl compound,and urea or thiourea using copper o-toluenesulfonate as a catalyst under solvent-free conditions at 90℃.Effects of molar ratio of reactants,amount of catalyst,and reaction temperature on the yields of 3,4-dihydropyrimidin-2-(1H)-ones were investigated.The results showed that at the condition of naldehyde∶n1,3-dicarbonyl compounds∶nurea(or thiourea)=1∶1.2∶1.5,1 mol% catalyst(molar percent of aldehyde),2.0 h at 90℃,the yields of products were 51-96%.After reaction,the catalyst could be reused for four times without distinct loss of catalytic activity.
