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On-surface Synthesis

On surface covalent synthesis as a means to form stable molecular nanostructures PhD student: Federico Masini Supervisor: Trolle R. Linderoth. D. +. On-surface Synthesis. Organic chemistry with molecules bound to surfaces under UHV conditions.

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On-surface Synthesis

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  1. On surface covalent synthesis as a means to form stable molecular nanostructuresPhD student: Federico MasiniSupervisor: Trolle R. Linderoth

  2. D + On-surface Synthesis Organic chemistry with molecules bound to surfaces under UHV conditions Self-assembled structures formed by weak, reversible interactions, e.g. H-bonding, have limited thermal and chemical stability Stability problem: Large organic compounds diffucult to deposit thermally due to fragmentation Deposition problem: Reaction must proceed in absence of solvent Conducting substrate close to reactants Steric effects from confinement on surface (topochemistry) No bulk local-probe counterpart to STM Fundamental interest:

  3. Trioctylamine formation Reaction

  4. Dosing Octylamine on Au(111) Octylamines form a lammelar structure on Au(111) at RT a) 100x100 Å2 b) 100x100 Å2 S. Weigelt, Ch. Bombis, A.X. Tuxen, F. Masini, Ch. Isvoranu, E. Ataman, J. Schnadt, F. Besenbacher and T.R. Linderoth, paper in preparation

  5. Annealing Octylamine on Au(111) Amines deposited on Au(111) surface, phase transition upon 400K a)Backbone imaging mode 170Åx170Å b) honeycomb phase and c) zig zag structure both in nitrogen imaging mode 100Åx100Å D=27±2Å dz=15±2Å dH=15±2Å S. Weigelt, Ch. Bombis, A.X. Tuxen, F. Masini, Ch. Isvoranu, E. Ataman, J. Schnadt, F. Besenbacher and T.R. Linderoth, paper in preparation

  6. Spectroscopical evidences (XPS) S. Weigelt, Ch. Bombis, A.X. Tuxen, F. Masini, Ch. Isvoranu, E. Ataman, J. Schnadt, F. Besenbacher and T.R. Linderoth, paper in preparation

  7. Dosing Trioctylamine on Au(111) D=26.5±3 Å a) 250x250 Å2 b) 100x100 Å2 S. Weigelt, Ch. Bombis, A.X. Tuxen, F. Masini, Ch. Isvoranu, E. Ataman, J. Schnadt, F. Besenbacher and T.R. Linderoth, paper in preparation

  8. Basic Reactions: imine formation

  9. Preparation procedure

  10. Surface polymer Monomer Loose end Dimer Gauche defect Two amines Annealed to 450 K S.Weigelt, Ch.Bombis, C,Busse, M.M. Knudsen, K.V. Gothelf, E Lægsgård,F.Besenbacher and T.R. Linderoth, paper in preparation

  11. Enhanced connectivity S.Weigelt, Ch.Bombis, C,Busse, M.M. Knudsen, K.V. Gothelf, E Lægsgård,F.Besenbacher and T.R. Linderoth, paper in preparation

  12. Enhanced Connectivity/2 S.Weigelt, Ch.Bombis, C,Busse, M.M. Knudsen, K.V. Gothelf, E Lægsgård,F.Besenbacher and T.R. Linderoth, paper in preparation

  13. Targets To achieve higher order, using amines with shorter carbon chains

  14. Targets/2

  15. Targets/3

  16. Surface polymerization is a promising way to form stable and ordered networks Next targets: getting more ordered and stable networks reducing the length of the carbon chains in interlinking diamines On-surface reactions of octylamines with formation of trioctylamine and dioctylamine are possible and that is demonstrated both spectroscopically and by STM Conclusions

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