锕系金属掺杂硼团簇AnB_(7)(An=Ac、Th、Am、Cm)的理论研究

Theoretical Study of Boron Clusters Doped With Actinides AnB_(7)(An=Ac,Th,Am,Cm)

通过金属掺杂,硼团簇可以表现出特殊的结构特征和化学性质。尽管主族金属、过渡金属和镧系金属掺杂的硼团簇已被相继报道,但目前锕系金属掺杂的硼团簇研究相对较少。本工作使用密度泛函理论(DFT)预测了一系列锕系金属掺杂硼团簇AnB_(7)(An=Ac、Th、Am、Cm)。理论计算表明,其能量最低的结构分别为C_(6)v AcB_(7)、C_(2)v ThB_(7)、C_(2)v AmB_(7)和C_(6)v CmB_(7),且均为半夹心构型。在每个AnB_(7)体系中,B_(3)-7具有六个离域的π电子和六个离域的σ电子,均为双重芳香性团簇。成键性质分析表明Am-B和Cm-B键的共价相互作用强于Ac-B和Th-B键。此外,这些硼团簇均非常稳定,且AmB_(7)和CmB_(7)稳定性更高,而共价相互作用是影响AnB_(7)稳定性的重要因素。本工作丰富了锕系金属掺杂的硼团簇的种类,并为设计锕系金属掺杂硼团簇材料提供了理论基础。

Through metal doping,boron clusters can exhibit special structural features and chemical properties.Although boron clusters doped with main group metals,transition metals and lanthanide metals have been reported previously,there are relatively few studies on boron clusters doped with actinide metals.In this work,a series of actinide metal-doped boron clusters AnB_(7)(An=Ac,Th,Am,Cm)were predicted.Density functional theoretical calculations show that the global minima are C_(6)v AcB_(7),C_(2)v ThB_(7),C_(2)v AmB_(7)and C_(6)v CmB_(7),and all are half-sandwich structures.In each AnB_(7)species,B_(3)-7 has six delocalizedπelectrons and six delocalizedσelectrons,all of which are double aromatic clusters.The analysis of bonding properties shows that the covalent interactions of Am-B and Cm-B bonds are stronger than those of Ac-B and Th-B bonds.In addition,these boron clusters are very stable,and AmB_(7)and CmB_(7)are more stable.Covalent interaction is an important factor affecting the stability of AnB_(7).This work enriches the types of boron clusters doped with actinide metal atoms,and provides a theoretical basis for the design of actinide metal doped boron cluster materials.