Tailoring the chemical reactivity and optical properties of clusters by size, structures and lasers
| Autor: | M. Hartmann, C. Bürgel, Vlasta Bonačić-Koutecký, H. Noack, Jiří Pittner, Roland Mitrić |
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| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | The European Physical Journal D. 34:113-118 |
| ISSN: | 1434-6079 1434-6060 |
| DOI: | 10.1140/epjd/e2005-00098-4 |
| Popis: | We present results of theoretical investigations in three areas. I. Reactivity of anionic noble metal oxide clusters (Ag, Au) relevant for catalyst design: It will be shown that the cooperative effects are needed to activate clusters in order to invoke strongly size selective reactions with O2 and CO. These results obtained with DFT method elucidated fully experimental findings. II. Stationary optical properties of silver clusters: ab initio results on absorption spectra of small silver clusters and on geometric relaxation of their excited states leading to the observed fluorescence are presented and compared with experimental data. III. Real-time investigation of ultrafast processes and their control by tailored laser fields: nonstoichiometric NanFn-1 clusters are suitable prototypes to study dynamics in excited electronic states. For this purpose we use our combination of the Wigner distribution method and MD “on the fly” allowing to treat all degrees of freedom. Analysis of simulated pump-probe signals will be shown for Na2F for which experimental data are available. Pump-dump control of the photoisomerization in Na3F2 avoiding conical intersection will be presented using our new strategy for obtaining tailored laser fields based on the intermediate target in excited state which (if available) guarantees the controllability in the complex systems. |
| Databáze: | OpenAIRE |
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