Work Package 4: Photochemical Devices

1. Work Package 4: Photochemical Devices Midterm-Review Meeting Molecular Machines- Design and Nano-Scale Handling of Biological Antetypes and Artificial Mimics Integrate appropriate Light-Fueled Molecular Components into nanomotors as alternative fueling concept Objectives CIAM, ETH, FZK-INT, ULP (additional contribution of MPI-FKF) Partners CIAM: 15 PM ETH: 21 PM FZK-INT 3 PM ULP: 3 PM PM Specific Targeted Research Project (STREP) in FP6-NMP-2002

2. Work Package 4: Photochemical Devices triggering molecular machine ENERGY molecular motor WORK FUNCTION monitoring Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002

3. Work Package 4: Photochemical Devices Midterm-Review Meeting Light stimulation ... ... can cause the occurrence of endergonic and reversible reactions ... is very easy to achieve (by means of lamps or lasers, or from the sun) ... allows a precise control of the amount of energy conferred to the chemical systems by adjusting the radiation’s intensity and wavelength ... can be switched on and off easily and rapidly ... can be performed with high spatial (down to nm level with near-field techniques) and temporal control (down to fs time domain) ... does not need to “touch” or “wire” the molecules to the energy source Specific Targeted Research Project (STREP) in FP6-NMP-2002

4. Work Package 4: Photochemical Devices M4-1 (m06): Planning and synthesis of a LFMC Midterm-Review Meeting Moreover ... ... photons can also be used to read the state of the system: by means of luminescence spectroscopy, for instance, detection can be made at the single molecule level ... the formation of waste products can be prevented by using “clean” photochemical reactions ... light stimulation allows the design of autonomous molecular motors M4-2 (m12): Photophysical characterization of LFMC‘s in solution D4-1 (m12): Final design of a LFMC Specific Targeted Research Project (STREP) in FP6-NMP-2002

5. Work Package 4: Photochemical Devices 1) Photoinduced electron transfer processes in multicomponent systems e– state A state B light-fueled component mechanical switching device isomer B isomer A 2) Photoisomerization reactions hn hn geometrical changes Midterm-Review Meeting Design strategies of light-driven molecular machines Specific Targeted Research Project (STREP) in FP6-NMP-2002

6. Work Package 4: Photochemical Devices State-of-the-art Photoinduced reversible shuttling in rotaxanes Murakami et al., J. Am. Chem. Soc.1997, 119, 7605 Ashton et al., Chem. Eur. J.2000, 6, 3558 Brouwer et al., Science 2001, 291, 2124 Anderson et al., Angew. Chem. Int. Ed.2002, 41, 1769 Light-driven rotary motors Feringa et al., Nature 1999, 401, 152 Org. Biomol. Chem.2003, 1, 33 Midterm-Review Meeting An artificial autonomous nanomotor driven by visible light Specific Targeted Research Project (STREP) in FP6-NMP-2002

7. Photosensitizer and stopper Rigid spacer Electron acceptor A2 Electron acceptor A1 Dumb stopper Work Package 4: Photochemical Devices Electron donor macrocycle A2 S P A1 T R CIAM (design; photochemical and electrochemical characterization; validation of motor operation in solution) Partners Collaboration with Fraser Stoddart, Dept Chemistry & Biochemistry and California Nanosystems Institute, University of California, Los Angeles (design; synthesis; structural characterization) Midterm-Review Meeting An artificial autonomous nanomotor driven by visible light Specific Targeted Research Project (STREP) in FP6-NMP-2002

8. Work Package 4: Photochemical Devices Midterm-Review Meeting An artificial autonomous nanomotor driven by visible light Conditions: Acetonitrile solution, room temperature Specific Targeted Research Project (STREP) in FP6-NMP-2002

9. Work Package 4: Photochemical Devices Midterm-Review Meeting An artificial autonomous nanomotor driven by visible light Conditions: Acetonitrile solution, room temperature Specific Targeted Research Project (STREP) in FP6-NMP-2002

10. Work Package 4: Photochemical Devices Midterm-Review Meeting An artificial autonomous nanomotor driven by visible light Conditions: Acetonitrile solution, room temperature Specific Targeted Research Project (STREP) in FP6-NMP-2002

11. Work Package 4: Photochemical Devices Midterm-Review Meeting An artificial autonomous nanomotor driven by visible light  = 2% Conditions: Acetonitrile solution, room temperature Specific Targeted Research Project (STREP) in FP6-NMP-2002

12. Work Package 4: Photochemical Devices Midterm-Review Meeting An artificial autonomous nanomotor driven by visible light NANOMOTOR MOVIE Specific Targeted Research Project (STREP) in FP6-NMP-2002

13. Work Package 4: Photochemical Devices Midterm-Review Meeting An artificial autonomous nanomotor driven by visible light • The present nanomotor constitutes a breakthrough compared to previous systems because it gathers together the following features: • it is powered by visible light, i.e., sunlight • it exhibits autonomous behaviour (like motor proteins) • it does not generate waste products since only photons are consumed • its operation relies only on intramolecular processes (no limitations of principle to single-molecule operation) • it is fast (it can be driven at a frequency exceeding 1 kHz) • it works in mild environmental conditions (ambient temperature, fluid solution) and is remarkably stable. Specific Targeted Research Project (STREP) in FP6-NMP-2002

14. Work Package 4: Photochemical Devices Computational study on the shuttling motion with Metadynamics • Metadynamics allows a fast escape from the energy basins and the identification of other stable and metastable configurations • The Free Energy Surface (FES) can be reconstructed with controlled accuracy ETH (theoretical and computational work); CIAM (experimental work) Partners Midterm-Review Meeting D4-2 (m18): Computational treatment of light-induced rotary movements in LFMCs Specific Targeted Research Project (STREP) in FP6-NMP-2002

15. Work Package 4: Photochemical Devices Midterm-Review Meeting Computational study on the shuttling motion with Metadynamics METADYNAMICS MOVIE Specific Targeted Research Project (STREP) in FP6-NMP-2002

16. Work Package 4: Photochemical Devices • Position of R along the thread • Number of hydrogen bonds between R and A1 • 3. Number of hydrogen bonds between R and A2 Collective variables Midterm-Review Meeting Computational study on the shuttling motion with metadynamics Specific Targeted Research Project (STREP) in FP6-NMP-2002

17. Work Package 4: Photochemical Devices A1– N. H-bond between R and A1– N. H-bond between R and A2 Position of R along the thread Position of R along the thread A2 N. H-bond between R and A2 N. H-bond between R and A1– Position of R along the thread Position of R along the thread Midterm-Review Meeting Free energy surfaces Specific Targeted Research Project (STREP) in FP6-NMP-2002

18. Work Package 4: Photochemical Devices Saddle A2 A2 <14 kcal/mol <9 kcal/mol A1– A1– Estimated error : 1 kcal/mol Midterm-Review Meeting The shuttling mechanism Experimental values determined by CIAM: A1– Saddle : ~12 kcal/mol A2 Saddle : ~14 kcal/mol Specific Targeted Research Project (STREP) in FP6-NMP-2002

19. Work Package 4: Photochemical Devices Midterm-Review Meeting The shuttling mechanism SHUTTLING MOVIE Specific Targeted Research Project (STREP) in FP6-NMP-2002

20. Work Package 4: Photochemical Devices State-of-the-art bulk: azodibenzoic acid bulk: azobenzene Midterm-Review Meeting M4-3 (m16): Self-assembly of LFMCs on surfaces Molecular motions on surfaces with a photoisomerization reaction Specific Targeted Research Project (STREP) in FP6-NMP-2002

21. Work Package 4: Photochemical Devices azodibenzoic acid F. Rakotondradany et al., Chem. Eur. J.2003, 9, 4771 self-assembly on surfaces ? effect of UV light on structures ? M4-3 (m16): Self-assembly of LFMCs on surfaces from linear chains... ...to cyclic tetramers ( 2.3 nm) Midterm-Review Meeting State-of-the-art:bulk self-assembly and UV light-induced isomerization FZK-INT (synthesis); MPI-FKF(STM experiment) Partners Specific Targeted Research Project (STREP) in FP6-NMP-2002

22. Work Package 4: Photochemical Devices ...through hydrogen bonding trans domains formation ...through metal-ligand interactions cavities Midterm-Review Meeting Self-assembly of azodibenzoic acid on Cu(100)… FZK-INT (synthesis); MPI-FKF(STM experiment) Partners Specific Targeted Research Project (STREP) in FP6-NMP-2002

23. Work Package 4: Photochemical Devices STM In collaboration with WP1 “Nanohandling„ UV Vis ? trans domains formation cis domains formation sublimation on Cu(100) surface Midterm-Review Meeting Ongoing Experiment: Light-induced Surface-Switching FZK-INT (synthesis); MPI-FKF(STM experiment) Partners Specific Targeted Research Project (STREP) in FP6-NMP-2002

24. Work Package 4: Photochemical Devices Integrate appropriate Light-Fueled Molecular Components into nanomotors as alternative fueling concept Objectives M4-1 (m06): Planning and synthesis of a LFMC M4-2 (m12): Photophysical characterization of LFMC‘s in solution M4-3 (m16): Self-assembly of LFMC‘s on surfaces Milestones D4-1 (m12): Final design of a LFMC (report) D4-2 (m18): Computational treatment of light-induced rotary movements (report) Deliverables • A light-powered nanomotor based on a rotaxane was successfully designed (CIAM, collaboration with UCLA), synthesized (UCLA) and operated (CIAM). Computational simulations on this system (ETH) have started to unravel the mechanism of the shuttling process, and are expected to be crucial for the design of novel prototypes with improved performance. 2) The trans-cis photoisomerization of an azobenzene derivative is being studied on a metal surface. The experiments performed by FZK-INT in connection with MPI-FKF (WP1) have shown that the azobenzene species can indeed be deposited as a monolayer onto a Cu(100) surface by sublimation under UHV, and that domains of the trans-isomer are formed. Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002