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

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

Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002 Work Package 4: Photochemical Devices... 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 Light stimulation...

Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002 Work Package 4: Photochemical Devices... 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 Moreover... M4-1 (m06): Planning and synthesis of a LFMC M4-2 (m12): Photophysical characterization of LFMC‘s in solution D4-1 (m12): Final design of a LFMC

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

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

Collaboration with Fraser Stoddart, Dept Chemistry & Biochemistry and California Nanosystems Institute, University of California, Los Angeles (design; synthesis; structural characterization) CIAM (design; photochemical and electrochemical characterization; validation of motor operation in solution) Partners Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002 Work Package 4: Photochemical Devices An artificial autonomous nanomotor driven by visible light Photosensitizer and stopper Rigid spacer Electron acceptor A 2 Electron acceptor A 1 Dumb stopper Electron donor macrocycle P S A2A2 A1A1 T R

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

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

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

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

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

Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002 Work Package 4: Photochemical Devices 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.

Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002 Work Package 4: Photochemical Devices 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 Computational study on the shuttling motion with ETH (theoretical and computational work); CIAM (experimental work) Partners D4-2 (m18): Computational treatment of light-induced rotary movements in LFMCs

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

Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002 Work Package 4: Photochemical Devices Computational study on the shuttling motion with metadynamics 1.Position of R along the thread 2.Number of hydrogen bonds between R and A 1 3.Number of hydrogen bonds between R and A 2 Collective variables

Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002 Work Package 4: Photochemical Devices Free energy surfaces A1–A1– Position of R along the thread N. H-bond between R and A 1 – N. H-bond between R and A 2 A2A2 Position of R along the thread N. H-bond between R and A 1 – N. H-bond between R and A 2

Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002 Work Package 4: Photochemical Devices The shuttling mechanism Experimental values determined by CIAM: A 1 –  Saddle : ~12 kcal/mol A 2  Saddle : ~14 kcal/mol A1–A1– A2A2 Saddle <14 kcal/mol<9 kcal/mol Estimated error : 1 kcal/mol A1–A1– A2A2

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

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

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

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

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

Midterm-Review Meeting Specific Targeted Research Project (STREP) in FP6-NMP-2002 Work Package 4: Photochemical Devices Objectives Integrate appropriate Light-Fueled Molecular Components into nanomotors as alternative fueling concept Milestones Deliverables 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 D4-1 (m12): Final design of a LFMC (report) D4-2 (m18): Computational treatment of light-induced rotary movements (report) 1)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.