Transcript WP4 - BIOMACH

Midterm-Review Meeting
Molecular MachinesDesign and Nano-Scale Handling of Biological Antetypes and Artificial Mimics
Work Package 4: Photochemical Devices
Objectives
Partners
PM
Integrate appropriate Light-Fueled Molecular Components
into nanomotors as alternative fueling concept
CIAM, ETH, FZK-INT, ULP
(additional contribution of MPI-FKF)
CIAM: 15 PM
FZK-INT 3 PM
ETH: 21 PM
ULP: 3 PM
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
triggering
molecular
machine
ENERGY
molecular
motor
WORK
FUNCTION
monitoring
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
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
Midterm-Review Meeting
Work Package 4: Photochemical Devices
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
M4-1 (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
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
Design strategies of light-driven molecular machines
1) Photoinduced electron transfer processes in multicomponent systems
hn
e–
state
A
light-fueled
component
state
B
mechanical
switching device
2) Photoisomerization
reactions
hn
isomer A
geometrical
changes
Specific Targeted Research Project (STREP) in FP6-NMP-2002
isomer B
Midterm-Review Meeting
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
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
An artificial autonomous nanomotor driven by visible light
A2
O
+
N
+
N
O
+
N
Electron
acceptor A1
N
N
Electron donor
macrocycle
O
N
O
T
O
O
N
+
N
O
RuII
A1
O
N
Dumb
stopper
O
Electron
acceptor A2
O
S
P
N
Rigid
spacer
O
Photosensitizer
and stopper
R
Partners
CIAM (design; photochemical and electrochemical characterization;
validation of motor operation in solution)
Collaboration with Fraser Stoddart, Dept Chemistry & Biochemistry and California Nanosystems
Institute, University of California, Los Angeles (design; synthesis; structural characterization)
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
An artificial autonomous nanomotor driven by visible light
Conditions: Acetonitrile solution, room temperature
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
An artificial autonomous nanomotor driven by visible light
Conditions: Acetonitrile solution, room temperature
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
An artificial autonomous nanomotor driven by visible light
Conditions: Acetonitrile solution, room temperature
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
An artificial autonomous nanomotor driven by visible light
 = 2%
Conditions: Acetonitrile solution, room temperature
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
An artificial autonomous nanomotor driven by visible light
NANOMOTOR MOVIE
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
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.
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
D4-2 (m18): Computational treatment of light-induced rotary movements in LFMCs
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
Partners
ETH (theoretical and computational work); CIAM (experimental work)
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
Computational study on the shuttling motion with
Metadynamics
METADYNAMICS MOVIE
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
Computational study on the shuttling motion with metadynamics
Collective variables
1.
2.
3.
Position of R along the thread
Number of hydrogen bonds between R and A1
Number of hydrogen bonds between R and A2
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
A1 –
N. H-bond between R and A2
N. H-bond between R and A1–
Free energy surfaces
Position of R along the thread
N. H-bond between R and A2
A2
N. H-bond between R and A1–
Position of R along the thread
Position of R along the thread
Position of R along the thread
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
The shuttling mechanism
Saddle
A2
<14 kcal/mol
A2
<9 kcal/mol
A1–
Estimated error : 1 kcal/mol
Experimental values determined by CIAM:
A1–  Saddle : ~12 kcal/mol
A2  Saddle : ~14 kcal/mol
Specific Targeted Research Project (STREP) in FP6-NMP-2002
A1–
Midterm-Review Meeting
Work Package 4: Photochemical Devices
The shuttling mechanism
SHUTTLING MOVIE
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
M4-3 (m16): Self-assembly of LFMCs on surfaces
Molecular motions on surfaces with a photoisomerization reaction
State-of-the-art
bulk: azobenzene
bulk: azodibenzoic acid
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
State-of-the-art: bulk self-assembly and UV light-induced isomerization
azodibenzoic acid
F. Rakotondradany et al., Chem. Eur. J. 2003, 9, 4771
from linear chains...
M4-3 (m16): Self-assembly
of LFMCs on surfaces
Partners
...to cyclic tetramers
( 2.3 nm)
self-assembly on surfaces ?
effect of UV light on structures ?
FZK-INT (synthesis); MPI-FKF (STM experiment)
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
Self-assembly of azodibenzoic acid on Cu(100)…
...through hydrogen bonding
trans
domains
formation
...through metal-ligand interactions
cavities
Partners
FZK-INT (synthesis); MPI-FKF (STM experiment)
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
Ongoing Experiment: Light-induced Surface-Switching
OH
O
N
N
O
HO
STM
In collaboration with
WP1 “Nanohandling„
UV
Vis
?
sublimation
on Cu(100) surface
Partners
trans
domains formation
cis
domains formation
FZK-INT (synthesis); MPI-FKF (STM experiment)
Specific Targeted Research Project (STREP) in FP6-NMP-2002
Midterm-Review Meeting
Work Package 4: Photochemical Devices
Objectives
Milestones
Deliverables
Integrate appropriate Light-Fueled Molecular Components
into nanomotors as alternative fueling concept
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.
Specific Targeted Research Project (STREP) in FP6-NMP-2002