新型锕系元素硼酸盐结构研究综述  

An Overview on Crystal Chemistry of Actinide Borates

作　　者：高阳[1] 赵岩岩[1,2] 第五娟 王殳凹 

机构地区：[1]苏州大学放射医学及交叉学科研究院,江苏苏州215123 [2]陕西师范大学化学化工学院,陕西西安710062

出　　处：《核化学与放射化学》2014年第1期1-16,共16页Journal of Nuclear and Radiochemistry

基　　金：基于聚合硼酸根晶格鉴别能力的新型镧锕分离方案基础研究(91326112)

摘　　要：近几年来,一系列新的锕系元素(钍、铀、镎、钚、镅、锔)硼酸盐化合物由硼酸熔融反应制备得到。这些化合物具有异常复杂的晶体结构以及非常优越的物理性质。硼酸钍具有纯无机多孔阳离子框架结构而拥有显著的阴离子交换性能,并能够选择性地将放射性核废液中的放射性核素99 Tc几乎完全提取出来,且保持高度的稳定性;硼酸铀化合物具有非常复杂的拓扑结构,且大部分结晶于非中心对称空间群;硼酸镎化合物经常显示出镎的混合价态,其中包含一个三重价态共存于同个化合物中的罕见例子,从而提供了一个崭新的轻锕系元素废料储放形式;硼酸钚提供了新奇的三价锕系元素配位环境;硼酸镅与硼酸锔同时显示出与硼酸钚与硼酸镧的显著差异,从而衍生出新的镧锕分离及锕系内部分离方略。迄今为止,关于超钚元素化合物的晶体结构与化学键的研究屈指可数,该系统研究具有非常显著的意义并且具有十足的挑战性。对此类化合物的进一步认识极有可能促进新一代核废料储放形式的探究及核燃料循环工艺的发展,进而阻止锕系放射性废物在环境中的扩散。In recent five years, a series of new actinide （including thorium, uranium, neptu- nium, plutonium, americium, and curium） borate compounds have been synthesized using molten boric acid flux reactions. These compounds possess both unusual structures and unprecedented properties. Thorium borate provides the first example of a cationic supertetra- hedral framework structure and displays remarkable anion exchange properties with high selectivity for TcO/. Uranium borates contain extraordinarily rich topological relationships with the majority crystallized in noncentrosymmetric space groups. Neptunium borates areoften mixed-valent with the first example of compound containing three oxidation states of actinides, which provides a new advanced waste form to stabilize most early actinides with all possible oxidation states. Plutonium borates display new coordination chemistry for trivalent actinides. Americium and curium Borate both show a dramatic departure from trivalent plutonium and lanthanide borates, which could potentially lead to new An（ Ⅲ ）/Ln（ Ⅲ ） and An（Ⅲ）/An（Ⅲ） separation strategies. There are still scant studies on the bonding of transplutonium element compounds up to now. Therefore, there are several grand challenges and importance that this work addresses. A deep understanding of material chemistry of these actinide borate compounds will likely lead to the development of waste disposal and radionuclide partitioning technologies.

关 键 词：锕系元素 硼酸盐 晶体结构 核废料处置 

分 类 号：O614.35[理学—无机化学] O641[理学—化学]