酸根离子及其水溶液对镎酰离子结构性质的影响

利用B3LYP杂化密度泛函方法，在相对论有效芯势模型下，优化得到了NpO22+离子及其配合物在气相和水溶液中的几何结构和电子结构, 研究了NO3-、SO42-和CO32-离子及其水溶液对NpO22+离子的结构和性质的影响.结果表明，NpO22+离子结合各种酸根离子后其Np=O键的键长都有明显增长、Np和O原子的价电子轨道能均有升高，而考虑溶剂化效应后酸根离子的影响将减小.电荷分析发现，结合酸根离子后，NpO22+中Np和O原子间形成的共价键的强度减弱、键长增长.对NpO22+离子与三种酸根离子的理论结合能的比较显示，NpO2CO3分子最为稳定.

The influence of Ligands on the structural properties of neptunyl ion in gaseous and aqueous phases

he geometries and electronic structure of NpO22+ ions and Neptunyl Complexes were obtained by using the relative effective core potential (RECP) at density functional theory (DFT). The influence of ligands on the structural properties of NpO22+ ions in gaseous and aqueous phases has been discussed. After NpO22+ ions binding ligands, Np=O bond length is longer, O=Np=O axial bond is bent, the bond energies from the valance orbitals of Np and O are increased. The influence of ligands on the structural properties of NpO22+ ions was reduced after considering solvation effects. Electron density analysis indicates that the coverlap between neptunium and the axial two oxygen atoms is diminished with NpO22+ ions binding ligands, as a result, the Np=O axial bond distance is elongated. Finally, according to the calculated binding energies between the three ligands and NpO22+ ions, NpO2CO3 is found to be the most stable molecule among the three Neptunyl Complexes.