硅、锗、锡、铅/磷二元原子团簇的形成、光解和结构

利用激光溅射产生了第IV主族 (硅、锗、锡、铅 ) /磷二元团簇正负离子 ,用飞行时间质谱研究了团簇离子的组成规律和激光光解产物 .研究表明二元团簇稳定性受团簇电子结构和几何结构的影响 ,但随着第IV主族元素自上而下 ,几何结构对团簇稳定性的作用越来越大 .在二元团簇离子中存在两类幻数团簇 :一类可以用Wade规则解释 ,其中磷原子或者充当给电子配体结合在第IV主族原子构成的团簇骨架外 ,或者直接参与团簇骨架的构成 ;另一类则与稳定的第IV主族中性团簇 (或磷中性团簇 )是等电子体 .利用从头计算和Wade规则对幻数团簇的结构和价键进行了分析 .

Formation,Photodissociation and Structures of Si,Ge,Sn,Pb/P Binary Atomic Cluster Ions

The formation and photodissociation of group Ⅳ(Si,Ge,Sn,Pb)/P binary cluster ions ,produced by laser ablation, were studied with a tandem TOF mass spectrometer. The stability of these cluster ions is influenced by their electronic and geometric structures ,and the geometric stability becomes more important for heavier group Ⅳ/P cluster ions. Two types of binary clusters marked with the magic numbers were observed: one type of magic clusters may be explained by the Wade's rule, in which P atom either attaches as electron-donating ligand to the closo-skeleton of group Ⅳatoms, or joins the closo-skeleton directly; another type of magic clusters are isoelectronic with magic species of neutral group Ⅳclusters or P clusters. The possible structures of magic cluster ions were studied by ab initio calculation and the Wade's rule.