Switchable ionic compounds have wide applications in chemical processes.A switchable ionic compound based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene(DBU),CH_3OH and CO_2 was synthesized and characterized.DBU/CH_3OH/CO_2 ...Switchable ionic compounds have wide applications in chemical processes.A switchable ionic compound based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene(DBU),CH_3OH and CO_2 was synthesized and characterized.DBU/CH_3OH/CO_2 ionic compound was prepared in the presence of excess methanol,and then the excess methanol was removed by reduced pressure distillation in CO_2 atmosphere.The product yield(100%) reached the theoretical maximum for the first time.Its structure was identified by NMR,FT-IR,and XRD.The crystal product shows 8strong peaks in XRD at 2θ values of 16.0547°,16.4308°,16.7651°,18.8714°,19.2140°,21.9471°,22.0780°,and25.5661°.Its decomposition onset temperature(53 ℃) was affirmed by TGA,which is lower than its melting point.And its ionic switch point was measured by conductivity.展开更多
基金Supported by the Doctoral Fund of Ministry of Education of China(20130181130006)the Key Program of National Natural Science Foundation of China(21336008)the National Natural Science Foundation of China(21476150)
文摘Switchable ionic compounds have wide applications in chemical processes.A switchable ionic compound based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene(DBU),CH_3OH and CO_2 was synthesized and characterized.DBU/CH_3OH/CO_2 ionic compound was prepared in the presence of excess methanol,and then the excess methanol was removed by reduced pressure distillation in CO_2 atmosphere.The product yield(100%) reached the theoretical maximum for the first time.Its structure was identified by NMR,FT-IR,and XRD.The crystal product shows 8strong peaks in XRD at 2θ values of 16.0547°,16.4308°,16.7651°,18.8714°,19.2140°,21.9471°,22.0780°,and25.5661°.Its decomposition onset temperature(53 ℃) was affirmed by TGA,which is lower than its melting point.And its ionic switch point was measured by conductivity.