Zhai Hua-Jin, Li Jun, Wang Lai-Sheng
Department of Physics, Washington State University, Richland, WA 99352, USA.
J Chem Phys. 2004 Nov 1;121(17):8369-74. doi: 10.1063/1.1799574.
We report the observation and characterization of a series of stable bimetallic 18-valence-electron clusters containing a highly symmetric 12-atom icosahedral Au cage with an encapsulated central heteroatom of Group VB transition metals, M@Au(12) (-) (M=V,Nb,Ta). Electronic and structural properties of these clusters were probed by anion photoelectron spectroscopy and theoretical calculations. Characteristics of the M@Au(12) (-) species include their remarkably high binding energies and relatively simple spectral features, which reflect their high symmetry and stability. The adiabatic electronic binding energies of M@Au(12) (-) were measured to be 3.70+/-0.03, 3.77+/-0.03, and 3.76+/-0.03 eV for M=V, Nb, and Ta, respectively. Comparison of density-functional calculations with experimental data established the highly symmetric icosahedral structures for the 18-electron cluster anions, which may be promising building blocks for cluster-assembled nanomaterials in the form of stoichiometric [M@Au(12) (-)]X(+) salts.
我们报告了一系列稳定的双金属18价电子簇合物的观测与表征，这些簇合物包含一个高度对称的由12个原子构成的二十面体金笼，笼内封装有VB族过渡金属的中心杂原子，即M@Au(12) (-)（M = V、Nb、Ta）。通过阴离子光电子能谱和理论计算对这些簇合物的电子和结构性质进行了探究。M@Au(12) (-)物种的特征包括其极高的结合能和相对简单的光谱特征，这反映了它们的高对称性和稳定性。对于M = V、Nb和Ta，M@Au(12) (-)的绝热电子结合能经测量分别为3.70±0.03、3.77±0.03和3.76±0.03 eV。密度泛函计算与实验数据的比较确定了18电子簇阴离子的高度对称二十面体结构，这些结构可能是以化学计量比的[M@Au(12) (-)]X(+)盐形式存在的簇组装纳米材料的有前景的构建单元。
