兰化物-EDTA协调复合体的水性结构通过联合DFT/EXAFS方法确定
Adam Smerigan1, Sayani Biswas2, Fernando D Vila3
1Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Inorganic chemistry
|August 25, 2023
概括
开发可持续的稀土元素 (REE) 分离技术需要了解水性联体结构. 这项研究确定了兰化物-乙烯基二胺三酸 (EDTA) 复合物的结构,揭示了更绿色的REE生产的见解.
科学领域:
- 无机化学 无机化学 有机化学
- 材料科学 材料科学 材料科学
- 环境科学 环境科学
背景情况:
- 对于电动汽车和风力轮机等绿色技术来说,稀土元素 (REEs) 的可持续生产至关重要.
- 目前的REE分离方法对环境产生了重大影响,推动了对可持续替代品的需求,例如基于亲和力的水分离.
- 了解水性联体结构和REE选择性之间的关系对于开发有效的分离策略至关重要.
研究的目的:
- 确定兰坦化物 (La,Ce,Pr,Nd) 复合物的水相结构与乙烯基二胺三酸 (EDTA).
- 提供结构洞察力,可以指导新型连接体的设计,以实现可持续的REE分离.
- 为了建立一个连接之间的连接结构和选择性对于水溶液中的单个REEs.
主要方法:
- 扩展的X射线吸收细结构 (EXAFS) 谱学被用来分析与EDTA复合的四种兰坦化物的协调环境.
- 密度函数理论 (DFT) 的计算被用来生成适合EXAFS光谱的参考结构.
- EXAFS数据分析的重点是确定Ln-EDTA复合体内的协调数,协调原子和平均第一个外距离.
主要成果:
- 所有四个兰他化物-EDTA复合体都表现出一个9坐标结构.
- 协调球由EDTA的6个原子 (4个碳氧氧,2个) 和3个水分子组成.
- 在兰坦化物系列 (La到Nd) 中观察到平均第一协调距离的下降,这与EXAFS和DFT结果一致.
- 高质量的EXAFS匹配 (R因子<0.02) 证实了结构的确定.
结论:
- 确定Ln-EDTA复合体的9坐标结构为在水溶液中的REE物种化提供了基本的见解.
- 这些发现对合理设计适用于选择性和可持续的稀土元素分离的配体有价值.
- 这项工作是朝着开发可再生能源生产的环保技术迈出的重要一步.
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