Complexation between uranyl(Ⅵ)and CMPO in a hydroxyl-functionalized ionic liquid:An extraction,spectrophotography,and calorimetry study  

作　　者：Baihua Chen Jun Liu Hongyuan Wei Yuchuan Yang Xingliang Li Shuming Peng Yanqiu Yang 

机构地区：[1]Institute of Nuclear Physics and Chemistry,CAEP,Mianyang 621900,China

出　　处：《Chinese Chemical Letters》2022年第7期3451-3455,共5页中国化学快报（英文版）

基　　金：supported by the National Science Foundation of China(Nos.22076175,11675156,U1830202 and 21976165)。

摘　　要：The extraction complexes of uranyl(Ⅵ)in HNO_(3)to a hydroxyl-functionalized ionic liquid(IL)phase,HOEtmimNTf2bearing CMPO,were investigated.Three possibly successive extraction complexes,UO_(2)L^(2+)(L=CMPO),UO2L_(2)^(2+) and UO_(2)L_(3)^(2+),were detected based on variable U/L ratios.Uranyl(Ⅵ)prefers to be extracted as complex UO_(2)L_(3)^(2+),combining with the ions from HOEtmimNTf_(2) to construct a solid material through self-assembly.The thermodynamics of complexes,UO_(2)L_(j)^(2+)(j=1-3),were studied by spectrophotometry and microcalorimetry.All the formation reactions are principally driven by entropy,although a small part of the driving force of complexes UO_(2)L_(2)^(2+)and UO_(2)L_(3)^(2+) comes from enthalpy.Based on the thermodynamic properties for complex UO_(2)L_(3)^(2+),we provide a possible coordination mode in HOEtmim NTf_(2):the first CMPO molecule coordinates with UO_(2)^(2+) in a bidentate fashion while the others do in a monodentate fashion.The results offer a thermodynamic insight into the formation behaviors of the uranyl(Ⅵ)/CMPO complexes involving the special IL HOEtmimNTf_(2),which is of significance to advance the novel IL extraction strategy.

关 键 词：Uranyl(Ⅵ) CMPO Ionic liquid Solvent extraction COMPLEXATION Thermodynamics 

分 类 号：O641.4[理学—物理化学] O657.3[理学—化学]