1,7-二氮杂15冠5醚对镧(Ⅲ)的配位识别机理研究  

Selective Recognition Mechanism of Lanthanum(Ⅲ)by 1,7-diaza 15 Crown 5 Ether

作　　者：吴江华 肖松文[2] 杨天足[1] 张杜超 夏大厦 万洪强 WU Jiang-hua;XIAO Song-wen;YANG Tian-zu;ZHANG Du-chao;XIA Da-sha;WAN Hong-qiang(School of Metallurgy and Environment,Central South University,Changsha 410083,Hunan,China;Changsha Research Institute of Mining&Metallurgy Co Ltd,Changsha 410012,Hunan,China;Hangzhou Yanqu Information Technology Co Ltd,Hangzhou 310012,Zhejiang,China)

机构地区：[1]中南大学冶金与环境学院,湖南长沙410083 [2]长沙矿冶研究院有限责任公司,湖南长沙410012 [3]杭州研趣信息技术有限公司,浙江杭州310012

出　　处：《矿冶工程》2021年第3期79-83,共5页Mining and Metallurgical Engineering

基　　金：国家自然科学基金(51704039);湖南省自然科学基金(2017JJ3320)。

摘　　要：研究了硫酸体系中氮杂冠醚萃取分离La^(3+)的过程,考察了氮杂冠醚浓度、平衡阴离子浓度对La^(3+)分配比的影响,并结合DFT计算和红外光谱表征探索了氮杂冠醚对硫酸体系中La^(3+)的配位结合机理。结果表明,La^(3+)与1,7-二氮杂15冠5醚形成8配位、La∶2N-15C5∶H_(2)O=1∶1∶3构型的配合物,配位反应的实质在于冠醚环上N原、O原子和水分子中的O原子与La^(3+)之间的离子偶极相互作用;在硫酸体系下,氮杂冠醚萃取La^(3+)所生成的萃合物结构式为La(2N-15C5)(H_(2)O)_(3)(SO_(4))_(0.5)^(2+),对应的萃取平衡常数K=2.88×10^(5)。In order to investigate the extraction process of La^(3+) by aza-crown ether in surfuric acid system,the impact on the distribution ratio of La^(3+) brought by the concentrations of aza-crown ether and equilibrium anion was studied.Furthermore,with the help of DFT calculation and infrared spectroscopy characterization,the extraction mechanism of La^(3+) in sulfuric acid system by aza-crown ether was also explored.It is found that La^(3+) and 1,7-diaza 15 crown 5 ether form a complex with 8 configuration,and the structure is La∶2 N-15 C5∶H_(2)O=1∶1∶3.And the essence of the extraction recognition lies in the dipole interaction among La^(3+) ion,N atom and O atom on the crown ether ring,as well as O atom in the water molecule;the formed complex after the La^(3+) is extracted by aza-crown ether in sulfuric acid system has the structure of La(2N-15C5)(H_(2)O)_(3)(SO_(4))_(0.5)^(2+),with the corresponding extraction equilibrium constant K=2.88×10^(5).

关 键 词：镧 氮杂冠醚 萃取平衡常数 分子识别 稀土萃取 

分 类 号：TF845[冶金工程—有色金属冶金]