Hu Shu-Xian, Zhang Peng, Lu Erli, Zhang Ping
School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.
Beijing Computational Science Research Center, Beijing 100193, China.
Inorg Chem. 2020 Dec 21;59(24):18068-18077. doi: 10.1021/acs.inorgchem.0c02539. Epub 2020 Dec 8.
Actinide metal oxo clusters are of vital importance in actinide chemistry, as well as in environmental and materials sciences. They are ubiquitous in both aqueous and nonaqueous phases and play key roles in nuclear materials (e.g., nuclear fuel) and nuclear waste management. Despite their importance, our structural understanding of the actinide metal oxo clusters, particularly the transuranic ones, is very limited because of experimental challenges such as high radioactivity. Herein we report a systematic theoretical study on the structures and stabilities of seven actinide metal oxo-hydroxo clusters [AnO(OH)L] (-An; An = Th-Cm; L = OCH) along with their group 4 (Ti, Zr, Hf, Rf) and lanthanide (Ce) counterparts [MO(OH)L] (-M). The work shows the -symmetric structures of all of the -An/M clusters and suggests the positions of the -OH functional groups, which are experimentally challenging to determine. Furthermore, by removing six electrons from -An, we found that oxidation could happen on the An metal ions, producing [AnO(OH)L] (-An; An = Pa, U, Np), or on the O and OH ligands, producing [An(O)(OH)(OH)L] (-An; An = Pu, Am, Cm). On the basis of -An, we constructed a series of tetravalent and pentavalent actinide metal oxo clusters [AnO] (-An) and [AnO] (-An), which proves the feasibility of the highly important pentavalent actinyl clusters, demonstrates the f orbital's structure-directing role in the formation of linear [O≡An═O] actinyl ions, and expands the concept of actinyl-actinyl interaction into pentavalent transuranic actinyl clusters.
锕系金属氧簇在锕系化学以及环境科学和材料科学中都至关重要。它们在水相和非水相中都普遍存在，并且在核材料（例如核燃料）和核废料管理中发挥着关键作用。尽管它们很重要，但由于诸如高放射性等实验挑战，我们对锕系金属氧簇，特别是超铀元素的氧簇的结构了解非常有限。在此，我们报告了对七个锕系金属羟基氧簇[AnO(OH)L]⁻（An；An = Th - Cm；L = OCH）及其第4族（Ti、Zr、Hf、Rf）和镧系（Ce）对应物[MO(OH)L]⁻（M）的结构和稳定性的系统理论研究。这项工作展示了所有An/M簇的对称结构，并表明了 - OH官能团的位置，而这些位置在实验上很难确定。此外，通过从An中移除六个电子，我们发现氧化可能发生在An金属离子上，生成[AnO(OH)L]⁻（An；An = Pa、U、Np），或者发生在O和OH配体上，生成[An(O)(OH)(OH)L]⁻（An；An = Pu、Am、Cm）。基于An，我们构建了一系列四价和五价锕系金属氧簇[AnO₂]²⁻（An）和[AnO₃]⁻（An），这证明了非常重要的五价锕酰簇的可行性，展示了f轨道在形成线性[O≡An═O]锕酰离子中的结构导向作用，并将锕酰 - 锕酰相互作用的概念扩展到五价超铀锕酰簇。
