1. 1 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Structures of Small Gold Cluster Ions Detlef Schooss Forschungszentrum Karlsruhe Institut für Nanotechnologie Physikalische Chemie by Trapped Ion Electron Diffraction (TIED)

2. 2 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy A.Sanchez, S.Abbet, U.Heiz, W.-D.Schneider H.Haekkinen, R.N.Barnett, U. Landman J. Phys. Chem. A 103, 9573 (1999) ½ O 2 + COCO 2 Au n / MgO Motivation - Nanoscale Catalysis

3. 3 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Experimental Setup TIED/KA :Nano Lett. 5, 1972 (2005) J. Chem. Phys 124, 244308 (2006) TIED: J. H. Parks et al., Phys. Rev. A 59, R3162 (1998)

4. 4 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy TIED - Cycles load 1-2 s mass selection cooling (100 K) He 1-2s TIED ~30 s detection read out CCD ion reference 500 ref -= ion

5. 5 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy TIED Data Reduction Fitting of theoretical scattering intensities sM theo of model structures to the experimental scattering intensities sM exp. with fitting parameters : R w = 5.1% Ag 55 +

6. 6 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Model Structures * D.J. Wales et al. http://www-wales.ch.cam.ac.uk /CCD.html  Density Functional Theory – Calculations TURBOMOLE, RIDFT (R. Ahlrichs et al.) Functional: TPSS Basis set: 7s5p3d1f Au: 19 e/atom explicitly, RECP Full geometry optimization, vibrational analysis, genetic algorithm  Initial structures from Construction of different structural motives Aufbau-principle Cambridge Cluster Database * Monte Carlo, genetic algorithm (empirical potential) Phys. Rev. A 77, 053202 (2008)

7. 7 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Structures of Au n -, n=11-20 Ionen Mobility / DFT, MP2 F. Furche, R. Ahlrichs, P. Weis, C. Jacob, S. Gilb, T. Bierweiler, and M. M. Kappes, J. Chem. Phys. 117 (15), 6982 (2002) Photo Electron Spektroscopy / DFT J. Li, X. Li, H.-J. Zhai, and L.-S. Wang, Science 299 (5608), 864 (2003), H. Häkkinen, B. Yoon, U. Landman, X. Li, H.-J. Zhai, and L.-S. Wang, J. Phys. Chem. A 107 (32), 6168 (2003) S. Bulusu, X. Li, L.-S. Wang, and X. C. Zeng, Proc. Natl. Acad. Sci. U. S. A. 103 (22), 8326 (2006) B. Yoon, P. Koskinen, B. Huber, O. Kostko, B. v. Issendorff, H. Häkkinen, M. Moseler, and U. Landman, ChemPhysChem 8 (1), 157 (2007) TIED / DFT X. Xing, B. Yoon, U. Landman, and J. H. Parks, Phys. Rev. B 74 (16), 165423 (2006) planar flat 3D cage tetrahedral

8. 8 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Structures of Au n -, n=11-20 planar flat 3D cage tetrahedral

9. 9 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy The 2D-3D Transition: Au 11 - 0.0 eV 0.32 eV 0.26 eV 0.19 eV* *Phys. Rev. A 77, 053202 (2008) 0.27 eV R w = 3.9 % R w = 12 % R w = 9.9 %

10. 10 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy The 2D-3D Transition: Au 12 - R w = 11 % R w = 4.3 % 0.0 eV 0.36 eV 0.17 eV* *Phys. Rev. A 77, 053202 (2008) Mixture: 2D/3D 0.15/0.85: R w = 3.4 %

11. 11 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Au 14 - R w = 3.7 % R w = 4.3 % R w = 18 % 0.0 eV 0.36 eV 0.11 eV saddle point !

12. 12 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Au 18 - R w = 6.3 % R w = 1.8 % R w = 5.6 %

13. 13 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Structures of Au n -, n=11-20 planar flat 3D cage tetrahedral

14. 14 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Structures of Au n +, n=11-20 trig. prism flat 3D cage mixture

15. 15 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Au 20 + R w = 8.5 % R w = 6.2 % R w = 5.5 %

16. 16 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Au 20 + : Isomer Mixture 60%40% R w = 2.6 R w = 8.7 % R w = 5.5 % 0.0 eV 0.26 eV

17. 17 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Summary TIED - structure assignment by comparison with model structures from DFT-calculations - size und charge state selective - cluster have a well defined temperature - sensitive to structural motif, bond lengths (~1%) cations trig. prisms n=11-13 flat 3D structures n=14-16 cage n=18 isomer mixture n=20 anions 2D-3D transition at n=12 flat 3D structures n=12-15 cages n=16-18 tetrahedral n=19,20 - good agreement with DFT predictions - exceptions: DFT prefers structures with extended (111) surfaces Structures of gold cluster ions: Au n +/-, n=11-20 - strong charge state dependence

18. 18 06/17/2008 - 63rd International Symposium on Molecular Spectroscopy Anne Lechtken Dr. Martine Blom Dr. Jason Stairs Lars Walter Prof. Dr. Manfred M. Kappes €€€: FZK und DFG (CFN) Acknowledgements Uni KA/FZK Dr. Christian Neiss Prof. Dr. Filipp Furche Prof. Dr. Reinhart Ahlrichs Dr. Mikael Johansson – Aarhus/Helsinki TIED DFT