Mn/Se,MnO2/Se和Mn/SeO2体系形成的团簇离子的质谱研究

用飞行时间质谱法研究了激光直接溅射Mn/Se混合样品产生的二元团簇、团簇的光解行为及溅射MnO₂/Se和Mn/SeO₂样品产生的团簇正负离子。在Mn-Se二元团簇中,(Muse)_n⁺是正离子的主要组分,[(Muse)nSe]^-是负离子的主要组分。当n<5时,(Muse)_n⁺的紫外光解有多种通道;n≥5时光解以剥落MuSe方式进行。激光直接溅射MnO₂/Se,Mn/SeO₂两种体系产生的正负离子极为相似,符合团簇的气相聚合生长机理。正离子中(Mno)_n⁺是主要组分,负离子中Se_n^-,(Se_nO)^-和(SéO₃)^-是主要组分。

A Study of Mn-Se and Mn-O-Se Cluster Ions Using Mass-spectrometry

Time-of-flight mass spectrometry was used to study Mn-Se and Mn-O-Se cluster ions produced by laser direct vaporization of solid samples. In Mn-Se binary cluster ions, (MuSe)n+ is the main composition of positive cluster ions, while [(MuSe)nSe]- is the main composition of negative cluster ions. When a mass-selected (MuSe)n+ was photolyzed, the photolysls produt ions have the same general composition (MuSe)m+. In Mn-O-Se ternary system, the main positive cluster ions produced are Mn-O binary clusters, in which [(MnO)n]+ has a high intensity, while the negative cluster ions include Sen-[SenO]-, [SenO3]- and [MnSen]-. It seems that the cluster ions were produced by the vaporization of solid sample and this conforms to a gas-phase aggregation mechanism.