Photo-fragmentation of atomic clusters with TOF mass spectrometer

通过改进激光-蒸发超声波扩展簇光束源，生成的簇被引入TOF质量光谱仪和FT-ICR质量光谱仪。Relatively large silicon clusters （Si-D210-D2 ？SiイイD230エD2） were generated and tested with both mass spectrometers。光片段实验和化学反应实验都是有效的。反应实验与乙烯和硝酸氧化物展示了一个有趣的对比。Ethylene molecules simply attached to Si clusters， while nitric oxides extracted a silicon atom as SiOs from silicon clusters。In Addition to these experimental studies， simple molecular dynamics simulations were performed to clarify the photo-dissociation mechanism of silicon clusters.金属-carbon binary clusters were studied for the understanding of formation Mechanism of single-walled carbon nanotubes and metal-including fullerenes。通过FT-ICR装置的化学反应实验，获得了一些碳和镍碳簇的几何信息。The La-car？clusters had the closed caged structure even for small size as La@C_D244_D2.这些簇的反应性非常低，无法与裸露的碳簇相比较。在另一只手上，Niatom似乎要附着在碳簇上。该簇似乎与镍原子反应不明显，与这些实验性工作一起，经典的分子动力学模拟是为碳和金属原子的簇形成过程而进行的。金属原子（Ni、Sc、La）之间的经典潜在函数和小簇的DFT计算中估计的碳原子。“La-碳簇和Ni-碳簇的预测结构可以很好地解释化学反应实验。”

By improving the laser-vaporization supersonic-expansion cluster beam source, generated cluster ions were introduced into the TOF mass spectrometer and FT-ICR mass spectrometer. Relatively large silicon clusters (SiィイD210ィエD2 ? SiィイD230ィエD2) were generated and tested with both mass spectrometers. The photo-fragmentation experiments and chemical reaction experiments were performed. The reaction experiments with ethylene and nitric oxide showed an interesting contrast. Ethylene molecules simply attached to Si clusters, while nitric oxides extracted a silicon atom as SiO from silicon clusters. In addition to these experimental studies, simple molecular dynamics simulations were performed to clarify the photo-dissociation mechanism of silicon clusters.Metal-carbon binary clusters were studied for the understandings of formation mechanism of single-walled carbon nanotubes and metal-including fullerenes. Through chemical reaction experiments with FT-ICR apparatus, some geometrical information of La-carbon and Ni-carbon clusters were obtained. The La-carbon clusters had the closed caged structure even for small size as La@CィイD244ィエD2. These clusters were much less reactive to NO compared with bare carbon clusters. On the other hand, Ni atom seemed to attach to the carbon clusters. The clusters with a Ni atom readily reacted with NO. Along with these experimental works, classical molecular dynamics simulations were performed for the clustering process from carbon and metal atoms. The classical potential functions between metal atoms (Ni, Sc, La) and a carbon atom were estimated from the DFT calculations of small clusters. The predicted structures of La-carbon clusters and Ni-carbon clusters could qualitatively explain the chemical reaction experiments.