U(Ⅵ)与二烷基二硫代膦酸配位化学研究  

Complexation of U(Ⅵ)with Dialkyldithiophosphinic Acid

作　　者：隋俏蕊 夏田田 邓琴 兰友世 杨素亮[1] 田国新[1,2] SUI Qiaorui;XIA Tiantian;DENG Qin;LAN Youshi;YANG Suliang;TIAN Guoxin(Department of Radiochemistry,China Institute of Atomic Energy,Beijing 102413,China;Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China)

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413 [2]清华大学核能与新能源技术研究院,北京100084

出　　处：《原子能科学技术》2024年第2期279-288,共10页Atomic Energy Science and Technology

摘　　要：二烷基二硫代膦酸类萃取剂有优良的三价锕系离子选择性,研究其与锕系离子的配位能够加深对该类萃取剂配位特性的理解。本文通过配合物单晶培养及结构分析、斜率法、拉曼光谱等手段研究了二(2,4,4-三甲基戊基)二硫代膦酸(纯化Cyanex_(3)01,HA)及二(2-甲基丙基)二硫代膦酸(HL)与U(Ⅵ)的配位化学。采用缓慢挥发法,成功获得了UO_(2)L_(2)·H_(2)O和UO_(2)L_(3)·(CH_(3))_(2)NH_(2)·H_(2)O两种新的配合物单晶,并测定了其结构及拉曼光谱。在以HA-二甲苯溶液为有机相、1.0 mol/L NaNO_(3)溶液为水相的萃取体系中,萃取U(Ⅵ)分配比与平衡有机相萃取剂浓度及水相酸度的关系表明,尽管萃取过程为阳离子交换,但可能生成两种不同比例的U(Ⅵ)与萃取剂萃合物;负载U(Ⅵ)有机相的拉曼光谱分析结果显示,在U(Ⅵ)浓度相对较低且自由萃取剂浓度较高的平衡有机相中,不含水萃合物占比较高,反之则容易生成水分子与U(Ⅵ)比例为1∶1的萃合物。关联负载U(Ⅵ)有机相、配合物晶体的拉曼光谱以及两种晶体的结构,推测两种萃合物分别为UO_(2)A_(2)·HA和UO_(2)A_(2)·H_(2)O。The complexation of U(Ⅵ)with two dialkyldithiophosphinic acids,bis(2,4,4-trimethylpentyl)dithiophosphinic acid(HA)and bis(2-methylpropyl)-dithiphosphinic acid(HL)was investigated by slope analysis method and X-ray diffraction method in solid compound along with Raman spectroscopy.In the solvent extraction system using HA in xylene as organic phase and U(Ⅵ)in 1.0 mol/L NaNO_(3)as aqueous phase,two extracted complexes of U(Ⅵ)are recognized in the organic phase by the slope analysis of the dependence of the distribution ratio on the concentration of HA in the organic phase and the pH in the aqueous phase,by Raman spectroscopy it is found that in one extracted complex formed in the organic phase with relatively low U(Ⅵ)loading but excessive free HA there is no water molecule coordinated with U(Ⅵ),while in the other one formed with relatively high U(Ⅵ)loading but less free HA in the organic phase there is one water molecule bonding to U(Ⅵ).By comparing the similarity and difference between the Raman spectra of the extracted complexes in the organic phase and the two solid U(Ⅵ)complexes with HL,UO_(2)L_(2)·H_(2)O and UO_(2)L_(3)·(CH_(3))_(2)NH_(2)·H_(2)O,along with analyzing their structures the extracted complexes are speculated to be UO_(2)A_(2)·HA and UO_(2)A_(2)·H_(2)O,respectively.Solid compound UO_(2)L_(2)·H_(2)O was prepared by slow evaporation method from kerosene solution equilibrated with an aqueous solution of same volume containing 1∶2 of U(Ⅵ)to L-.It is crystalized in I2/a space group with unit cell:a=8.6066(2),b=20.9166(3),c=15.1847(3);α=90°,β=105.337(2)°,γ=90°;Z=4.In UO_(2)L_(2)·H_(2)O complex,two bidentate L-providing totally four sulfur atoms along with one oxygen from the water molecule coordinate with U(Ⅵ)in the equatorial plane to form a typical pentagonal bipyramid structure.The other solid compound UO_(2)L_(3)·(CH_(3))_(2)NH_(2)·H_(2)O was obtained directly from aqueous solution containing 1∶3 of U(Ⅵ)to(CH_(3))_(2)NH_(2)L by slow evaporation.It is crystaliz

关 键 词：U(Ⅵ) 配位化学 二(2 4 4-三甲基戊基)二硫代膦酸 二(2-甲基丙基)二硫代膦酸 晶体结构 

分 类 号：TL24[核科学技术—核燃料循环与材料] O641.4[理学—物理化学]