B2Au20/-/2-: 硼金团簇中的硼-硼多重键

采用密度泛函和波函数理论方法对B₂Au^20/-/2-的几何结构和电子结构进行研究. 计算结果表明阴离子B₂Au^2- (Au-B B-Au]^-) (C_2h, ²A_u)和B₂Au^22- (Au-B≡B-Au]^2-) (C_2h, ¹A_g)的基态结构均为线性结构, 即以含有多重键的BB单元(B B或B≡B)为中心, 两端各连接一个Au原子, 但两端的B－Au键不在同一直线上, 结构稍有变形; 而中性分子B₂Au₂ (Au-B＝B-Au]) (D_∞h, ³Σ_g^-)的基态结构是以B＝B为中心, 两端各与一个Au原子相连的完美的线性结构. C_2h B₂Au^2-的单电子垂直剥离能和对称性伸缩振动频率的计算结果为实验表征提供依据.另外, 计算发现无机盐B₂Au₂Li₂结构中仍包含B≡B, 此结果一方面为其实验合成提供了可能性, 另一方面表明含有B≡B的B₂Au₂^2-结构极为稳定, 可作为结构单元存在于凝聚相中.

B2Au20/-/2-: Multiple Boron-Boron Bonds in Diboron Aurides

A density functional theory (DFT) and wave function theory investigation on the structures and electronic properties of B₂Au₂^0/-/2- clusters has been performed. Both the doublet B₂Au^2- (Au-B B-Au]^-) (C_2h, ²A_u) and the singlet B₂Au₂^2- (Au-B≡B-Au]^2-) (C_2h, ¹A_g) have distorted linear ground-state structures containing a multiply bonded BB core (B B or B≡B) terminated by two Au atoms, while neutral B₂Au₂ (Au-B＝B-Au]) (D_∞h, ³Σ_g^-) has a perfect linear geometry. One-electron detachment energies and symmetrical stretching vibrational frequencies were calculated for C_2h B₂Au^2- facilitate their future characterizations. A neutral salt of B₂Au₂Li₂ with an elusive B≡B triple bond is predicted, which is a possible target for experiments. The high stability of B₂Au₂^2- suggests that it may exist as a viable building block in the condensed phase.