Photo-fragmentation of atomic clusters with TOF mass spectrometer

使用laser-vaporization supersonic-expansion cluster beam source，generated cluster ions into the TOF mass spectrometer and FT-ICR mass spectrometer。Relatively large silicon clusters (Si D210 - D2 ？Si - D230 - D2) were generated and tested with both mass spectrometers. The photofragmentationexperiments and chemical反应experiments performed. The反应experiments with ethylene和nitric oxide showed an interesting contrast. Ethylene molecules简单attached to Si clusters，while nitric oxides extracted a silicon atom as SiO from silicon clusters In addition to theseexperimental studies,simple molecular dynamics simulations were performed to clarify the photo-dissociation mechanism ofsilicon cluster . metal -carbon binary clusters studied for the understandings of formationmechanism of single-walled carbon nanotubes and metal-including fullerenes. Through chemical反应实验与FT-ICR apparatus，La-carbon and Ni-carbon clusters some geometrical information of La-carbonclusters had the closed caged structure even for small size as La@C D244 D2.这些clusters weremuch 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 a Ni atom readily reacted with a Ni atom readily reactedNO. ong with these experimental worksclassical molecular dynamics simulations performed for the clustering process from carbon andmetal atoms. The classical potential functions between metal atoms （Ni, Sc, Sc）a) and a carbon atom were estimated from the DFT calculations of small clusters. the predictedLa-carbon clusters and Ni-carbon clusters could qualitatively explain the chemical structures of La-carbon clusters and Ni-carbon clusters could qualitatively explain the chemicalreaction experiments。

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.