From ambient to extreme conditions: a systematic investigation of actinides chemistry in fission products based oxo-salt systems

锕系元素（An）和相关材料的化学性质的知识是正确的乏核燃料和废物形式安全评估的关键，是基础科学的高度兴趣。锕系元素是5 f元素，具有许多独特的化学（多价，极其多样化的配位化学）和物理（磁有序，超导性）特性。到目前为止，锕系元素科学的一些化学方面还不清楚，特别是它们的反应性对可变合成条件的依赖性，特别是与乏核燃料和储存库条件有关的条件，以及5 f-电子在An中心和氧代盐配体之间的键合中的进一步作用。在研究过程中，我们将联合收割机结合德国和中国合作伙伴的独特专业知识，对早期锕系元素Th、U、Np和Pu及其与基于关键裂变产物的含氧盐基团（例如Se、I、Mo）的相互作用进行系统研究。我们将在从环境压力和室温到2500 °C和25 GPa的各种合成条件下进行这项研究。我们将研究所得材料的化学和结构性质，特别强调电子结构，以及5 f电子参与成键的进一步关系。Alekseev教授（德国于利希）的小组将重点关注固态反应，特别强调压力和温度的极端条件。王教授（中国苏州）的小组将负责研究水溶液中的反应，包括涉及超临界水的反应。由于这一中德联合项目，我们预计将在以下方面取得相当大的科学进步：1。早期锕系元素的合成化学，从环境到极端压力和温度的各种合成条件下的反应性和相形成;2。早期锕系元素基含氧材料的结构化学; 3.对An中心与不同类型的氧代配体之间的成键性质的理解。我们相信，DFG-NSFC联合项目将把我们的合作带到一个新的、高效的性能水平，并将在德中放射化学领域的科学合作中发挥重要作用。

The knowledge of the chemical properties of actinide elements (An) and associated materials are crucial for correct spent nuclear fuel and waste form safety assessments and are of high interest for fundamental science. The actinides are 5f-elements, which possess a plethora of unique chemical (multi-valence, extremely diverse coordination chemistry) and physical (magnetic ordering, superconductivity) properties. Until now several chemical aspects of actinide science are unclear, particularly the dependence of their reactivity to variable synthetic conditions, particularly those relevant to spent nuclear fuel and repository conditions, and the further role of 5f-electrons in bonding between An centers and oxo-salt ligands. Within the research we will combine the unique expertise of German and Chinese partners to perform a systematic investigation of the early actinides, Th, U, Np, and Pu, their interaction with oxo-salt groups that are based on key fission products, for instance Se, I, Mo. We will perform this study in a wide range of synthetic conditions ranging from ambient pressure and room temperature up to 2500 °C and 25 GPa. We will study chemical and structural properties of the obtained materials with a particular emphasis on electronic structure the further relation of 5f-electrons involvement in bonding. The group of Prof. Alekseev (Jülich, Germany) will focus on solid state reactions with particular emphasis on extreme conditions of pressure and temperature. The group of Prof. Wang (Suzhou, China) will be responsible for the investigation of reactions in aqueous solutions including those involving supercritical water. As a result of this joint Sino-German project we expect considerable scientific advancement in: 1. Synthetic chemistry of the early actinides in respect to their reactivity and phase formation at various synthetic conditions from ambient to extreme pressures and temperatures;2. Structural chemistry of early actinide based oxo-materials; 3. The understanding of the bonding nature between An centers and different type of oxo-ligands.We believe that this DFG-NSFC joint project will bring our cooperation onto a new, highly effective performance level and will play a significant role in German-Chinese scientific cooperation in the field of radiochemistry.