Liu Kang, Chi Xiao-Wang, Guo Yan, Wu Qun-Yan, Hu Kong-Qiu, Mei Lei, Chai Zhi-Fang, Yu Ji-Pan, Shi Wei-Qun
Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing100049, China.
Inorg Chem. 2022 Nov 14;61(45):17993-18001. doi: 10.1021/acs.inorgchem.2c02263. Epub 2022 Nov 4.
The involvement of the 2-phosphaethynolate anion species with ambident nucleophilic properties serves as an essential protocol for synthesizing oxygen-bound or phosphorus-bound complexes. This work mainly describes the synthesis and characterization of U, Th, and Ti phosphaethynolate complexes featuring a preferential O-coordination fashion. Among these complexes, the first examples of a Ti(IV)-OCP complex 3A, Th(IV)-OCP complex 3B, and U(IV)-OCP complex 3C were assembled by a salt metathesis reaction between M(Trapen)(Cl) (M = Ti, Th, U) and NaOCP(dioxane) and were all crystallographically characterized. The structural similarity of this series of phosphaethynolate complexes allows us to compare the bonding properties of d- and f-block elements in the corresponding compounds. The well-established density functional theory (DFT) computational method was employed to explore the electronic structures and covalency in M-O bonding, and the results showed a consistent pattern. The calculation result showed that 2-phosphaethynolate complexes exhibited the covalency trend of U-O > Th-O > Ti-O due to the involvement of 5f orbitals.
具有双齿亲核性质的2-磷乙炔酸根阴离子物种的参与是合成氧配位或磷配位配合物的重要方法。这项工作主要描述了具有优先O配位方式的U、Th和Ti磷乙炔酸酯配合物的合成与表征。在这些配合物中，通过M(Trapen)(Cl)（M = Ti、Th、U）与NaOCP(二氧六环)之间的盐复分解反应组装了首例Ti(IV)-OCP配合物3A、Th(IV)-OCP配合物3B和U(IV)-OCP配合物3C，并对它们进行了晶体学表征。这一系列磷乙炔酸酯配合物的结构相似性使我们能够比较相应化合物中d族和f族元素的键合性质。采用成熟的密度泛函理论（DFT）计算方法来探究M-O键中的电子结构和共价性，结果呈现出一致的规律。计算结果表明，由于5f轨道的参与，2-磷乙炔酸酯配合物呈现出U-O > Th-O > Ti-O的共价性趋势。
