钽硫原子簇的形成及激光裂解的初步研究

报导用激光直接溅射的方法产生了大量的钽硫原子团簇离子Ta_nS_m~+(n≤9, m≤30),并用串级飞行时间质谱仪研究了所产生团簇离子的组成及紫外激光裂解规律。实验发现, 最稳定的团簇正离子往往具有Ta_nS_(2n+7)~+(n=1,2,…9)的组成, 相应的负离子具有, Ta_nS_(2n+3)~-(n=1,2,…9)的组成。各种团簇正离子的激光裂解的主要通道是连续的S_2消除过程, 且对于n=3,4,5的团簇, 主要光解产物还有Ta_3S_4~+或Ta_4S_6~+离子。据此推测出Ta_nS_m~+团簇离子的可能结构为在Ta原子周围有6个左右的S原子配位。Ta原子之间不存在直接的化学键,而较大团簇可能是以Ta_3S_4或Ta_4S_6为核心的结构。

A Primary Study of the Formation and Photolysis of Tantalum Sulfide Cluster Ions

Tantalum sulfide cluster ions (Ta_nS_m~+, n≤9, m≤30) were produced by direct laser ablation of a mixture of tantalum and sulfur powders and studied by a tandem timeof-flight mass spectrometer. It was found that the most stable tantalum sulfide cluster ions were Ta_mS_(2n+7)~+, (n=1-9). The main dissociation channel of the UV-photolysis (248 nm) of tantalum sulfide cluster ions is sequent S_2 loss. For cluster ions with n≥3, besides the S_2 loss channel, the photolysis yields Ta_3S_4~+, or Ta_4S_6~+, as nucleus was suggested for large tantalum sulfide cluster ions.