Multitasking with Chemical Fuel: Dissipative Formation of a Pseudorotaxane Rotor from Five Distinct Components

Article abstract of DOI:10.1021/jacs.1c01948

A 3-fold completive self-sorted library of dynamic motifs was integrated into the design of the pseudorotaxane-based rotor [Zn(2·H+)(3)(4)]2+ operating at k298 = 15.4 kHz. The rotational motion in the five-component device is based on association/dissocia

Full text of DOI:10.1021/jacs.1c01948

pubs.acs.org/JACS
Communication
Multitasking with Chemical Fuel: Dissipative Formation of a
Pseudorotaxane Rotor from Five Distinct Components
Amit Ghosh, Indrajit Paul, and Michael Schmittel*
Cite This: J. Am. Chem. Soc. 2021, 143, 5319−5323
Read Online
sı
*
Metrics & More
Article Recommendations
Supporting Information
ACCESS
ABSTRACT: A 3-fold completive self-sorted library of dynamic motifs was integrated into the design of the pseudorotaxane-based
rotor [Zn(2·H+)(3)(4)]2+ operating at k298 = 15.4 kHz. The rotational motion in the five-component device is based on association/
dissociation of the pyridyl head of the pseudorotaxane rotator arm between two zinc(II) porphyrin stations. Addition of TFA or 2-
cyano-2-phenylpropanoic acid as a chemical fuel to a zinc release system and the loose rotor components 2−4 enabled the liberated
zinc(II) ions and protons to act in unison, setting up the rotor through the formation of a heteroleptic zinc complex and a
pseudorotaxane linkage. With chemical fuel, the dissipative system was reproducibly pulsed three times without a problem. Due to
the double role of the fuel acid, two kinetically distinct processes played a role in both the out-of-equilibrium assembly and
disassembly of the rotor, highlighting the complex issues in multitasking of chemical fuels.
hemical fuels play a central role in setting up dissipative
systems on the molecular level, e.g., in host−guest
C
systems,1−3 transient switching,4−6 ratcheted directional
motion,7,8 catalysis using molecular machines,9 and the
generation of supramolecular materials10−14 and self-replica-
tors.15 However, to achieve feedback control as in living
organisms, it would be desirable to have man-made functional
multicomponent devices be dissipatively generated to perform
vital tasks and to disappear after completion of their work.16−19
Here, we demonstrate the out-of-equilibrium self-assembly and
operation of a five-component rotor by a single chemical fuel. In
contrast to fueled homo-oligomeric aggregation,10 multitasking
of the fuel is required, as distinct binding events need to be set up
for the assembly of five components.
While the potential of synthetic molecular machines has been
widely recognized,20−24 most of them are covalently assembled,
whereas biological machines are typically composed of different
components.25,26 Except for a limited amount of cases,27−34
artificial multicomponent machinery remains rare, due to a lack
of tools for controlling their dynamics parallel in space and
time.35 Capitalizing on a small number of dynamic orthogonal
metal−ligand interactions, our group has started to prepare
diverse multicomponent stand-alone devices36 and functional
multicomponent networks.37,38 Thus, fueling metal ion release
would open a multitude of opportunities due to the broad
availability of metal-ion dependent devices.20
To date, the only artificial multicomponent system
commanded by chemical metal-ion pulses is a lithium(I)-
based AND gate39 designed as a communicating network. For
the present project we envisaged that acid 6, developed by Di
Stefano et al.,40 as chemical fuel should initiate two out of three
binding events in the dissipative formation of the five-
component pseudorotaxane-based rotor 5 = [Zn(2·H+)(3)-
(4)]2+ from its constituents by (i) protonating ligand 2 (for
pseudorotaxane formation) and (ii) liberating zinc(II) ions from
[Zn(1)]2+ (Figure 1).
Figure 1. Chemical communication generates a transient rotor.
Self-sorting41,42 as a key technology to assemble multi-
component devices27−34 is based on the use of multiple
orthogonal dynamic interactions. Lately, we have shown that
the HETTAP43 (Heteroleptic Terpyridine and Phenanthroline)
Received: February 19, 2021
Published: March 31, 2021
https://doi.org/10.1021/jacs.1c01948
J. Am. Chem. Soc. 2021, 143, 5319−5323
© 2021 American Chemical Society
5319

Journal of the American Chemical Society
pubs.acs.org/JACS
Communication
linkage is fully orthogonal to the pyridine→zinc(II) porphyrin
(Npy→ZnPor) binding but never in combination with a
pseudorotaxane-type complexation motif.44 Whereas the
pseudorotaxane unit has been the basis of many intricate
assemblies45 and interlocked molecular machines,46−48 its utility
in multicomponent molecular devices is still unexplored. Here,
the pseudorotaxane motif serves not only as a dynamic corner of
the five-component rotor along with the HETTAP and Npy→
ZnPor complexation but also as an anchor point for its out-of-
equilibrium formation.
Prior to designing detailed components of the rotor, three
fully orthogonal binding motifs were required with at least one
being responsive to an acid fuel. In this regard, we identified
complexes C1, C2, and C3 as promising candidates (Figure 2)
the ammonium moiety, shifted downfield from 4.95 and 4.00 to
5.51 and 5.27 ppm, respectively. The threading was also
confirmed by the emergence of multiple sets of cyclic ether
protons in the aliphatic region. UV−vis, fluorescence, and ESI-
MS (Supporting Information, Figures S67, S72, and S63)
further proved the formation of pseudorotaxane [(2·H+)(3)]
(log K = 5.58 0.03, Supporting Information, Figure S69).
The bent geometry of [(2·H+)(3)] with its terpyridyl and
pyridyl terminals allowed two connections to ligand 4 after
addition of Zn(OTf)2, one via a HETTAP linkage and the other
via Npy→ZnPor binding. The zinc(II) ion set up a strong
HETTAP43 complex between the central phenanthroline of 4
and the terpyridyl unit of the pseudorotaxane, whereas the
pyridine terminal of rotator [(2·H+)(3)] formed an Npy→ZnPor
coordination. The pyridine was expected to move quickly
between the two identical ZnPor binding sites, giving rise to
rotor 5 (Figure 3a). As expected from the clean self-sorting of
Figure 3. (a) Synthesis of rotor 5. (b) Comparison of partial 1H NMR
spectra (CD2Cl2, 400 MHz) of pseudorotaxane [(2·H+)(3)], 4, and
rotor 5.
Figure 2. Complexation motifs used in the five-component
pseudorotaxane rotor.
the basic building blocks, rotor 5 was furnished quantitatively, as
evident from 1H NMR, 1H−1H COSY, DOSY, and electrospray
mass spectroscopy (ESI-MS). For instance, ESI-MS peaks at m/
z = 1908.4 (doubly charged) and 1222.7 (triply charged)
attested the formation of [Zn(2·H+)(3)(4)]2+ (Supporting
Information, Figure S65). 1H NMR analysis showed the
characteristic upfield shifts of proton signals 10-H from 10.34
to 10.21 ppm and 15-H from 6.38 to 5.78 ppm, proving the
existence of both Npy→ZnPor and HETTAP complexation
(Figure 3b). Similarly, the pyridyl protons a′/b′-H were
characteristically shifted upfield from 8.54/7.25 ppm to 2.21/
5.36 ppm due to coordination at the ZnPor. The pseudorotax-
ane linkage was indicated by the signals of protons 21-H and 20-
H, adjacent to the ammonium moiety, that appeared at 5.43 and
5.15 ppm. Finally, a single set of 1H-DOSY signals (D = 4.5 ×
10−10 m2 s−1, r = 11.8 Å, in CD2Cl2) supported the formation of
the assembly (Supporting Information, Figure S47).
To measure the exchange frequency in rotor 5, we analyzed
the signal (Figure 4a) of proton 10-H, which showed up as a
sharp singlet (10.21 ppm) at 25 °C in the variable temperature
1H NMR. The single set of protons for both porphyrin units
attested fast rotation on the 1H NMR time scale. Diagnostically,
at −50 °C, it separated into two singlets (1:1) at 10.30 and 10.19
ppm. The signal at 10.19 ppm was assigned to the pyridine-
coordinated ZnPor station, whereas the upfield signal at 10.30
ppm referred to the freely rotating ZnPor. The kinetic analysis
provided the exchange frequency k at different temperatures,
with k298 = 15.4 kHz. From the Eyring equation, the activation
due to their interference-free self-sorting. As shown in Figure 2,
mixing of stoichiometric amounts of (7·H+)PF6 , 8−12, and
−
Zn(OTf)2 (1:1:1:1:1:1:1) generated the pseudorotaxane C1 =
[(7·H+)(11)]PF6 (log K = 4.74 0.20, Supporting Informa-
−
tion, Figure S68) and the strong HETTAP complex C2 =
[Zn(8)(10)]2+ (log β ≈ 15.0, Supporting Information, Figure
S70) together with the well-established Npy→ZnPor complex-
ation motif C3 = [(9)(12)] (log K = 4.31 0.12).49
On the basis of this insight, we designed the five components
of the rotor: protons, ligands 2, 3, and 4, and zinc(II) ions
(Figure 1). First, ligand 4 that contains two zinc(II) porphyrin
stations at both terminals and a phenanthroline station in the
middle was synthesized according to a known procedure.50 The
dibenzo-24-crown-8 and terpyridyl motifs were combined in
ligand 3, which acts as an axis of rotor 5. The rotator arm 2 was
conceived as a secondary amine with an anthracene stopper
carrying additionally a pyridine terminal. For the full synthesis of
2 and 3, see Schemes S1 and S2 in the Supporting Information.
When ligands 2, 3, and TFA were mixed (1:1:1) in DCM, the
ammonium moiety of the linear component 2·H+ (referred to as
thread) slid into the macrocycle of ligand 3. As expected, the 1H
NMR spectrum showed the typical upfield shifts of the crown’s
aromatic proton signals m-H, l-H, and n-H, while the peak at
6.89 ppm corresponding to o-H and p-H split in two sets
(Supporting Information, Figure S51). The signals of
anthracenyl and benzyl protons 21-H and 20-H, adjacent to
5320
https://doi.org/10.1021/jacs.1c01948
J. Am. Chem. Soc. 2021, 143, 5319−5323

Journal of the American Chemical Society
pubs.acs.org/JACS
Communication
Figure 4. (a) Experimental (right) and simulated (left) variable
temperature 1H NMR spectra of rotor 5 (signal of proton 10-H) and
the exchange frequency k. (b) Eyring plot.
parameters were calculated as ΔH⧧ = 53.1 1.8 kJ mol−1, ΔS⧧ =
14.6 7.4 J mol−1 K−1, and ΔG⧧ = 48.7 0.4 kJ mol−1
298
Figure 5. Transformation of NetState-I → NetState-II with TFA. (a)
The proton 10-H signal (1H NMR) shows formation of rotor via the
intermediate prerotor assembly. (b) The prerotor/rotor is shown at
different amounts of TFA.
(Figure 4b).
After setting up a five-component rotor, our next vision was to
generate and operate it in an out-of-equilibrium fashion. On the
basis of the rotor components, we combined ligands 2−4 and
zinc(II) (Figure 1) with hexacyclen (1), expecting that, in a
clean self-sorting reaction, Zn2+ would coordinate exclusively to
hexacyclen (NetState I). Now the consequential idea was to add
an acid (2 equiv) to protonate the complex [Zn(1)]2+, thus
liberating Zn2+ to join ligands 3 and 4 in a HETTAP43 complex
and simultaneously to protonate the amine of ligand 2 to create a
pseudorotaxane linkage with ligand 3. Eventually, the combina-
tion of both these complexes was expected to furnish NetState-II
composed of [H(1)]+ and rotor [Zn(2·H+)(3)(4)]2+.
As planned, self-sorting of zinc(II) in the presence of 1−4 in a
1:1:1:1:1 ratio cleanly delivered [Zn(1)]2+ with all other ligands
in NetState-I left unassociated, as indicated by 1H NMR
spectroscopy (in dichloromethane-d2). Upon addition of 2
equiv of TFA, the 1H NMR spectrum (Supporting Information,
Figure S55) showed complete translocation of Zn2+ from
hexacyclen to ligand 3 and 4 and simultaneous formation of the
pseudorotaxane, which eventually generated the rotor (Net-
State-II). The ESI-MS showed the presence of both complexes
[Zn(2·H+)(3)(4)]2+ and [H(1)]+ by peaks at m/z = 1908.0
(doubly charged) and a signal at m/z = 259.7 (singly charged)
(Supporting Information, Figure S66). Reverse translocation of
zinc(II) from rotor 5 back to hexacyclen was readily achieved
after addition of 2 equiv of DBU.
When NetState-I was titrated with TFA, from the beginning it
showed formation of prerotor [Zn(2)(3)(4)]2+ and only
thereafter rotor 5 (Figure 5a). Formation of the assemblies
was followed by the distinct 1H NMR signals of protons 10-H in
ligand 4, prerotor, and rotor. Upon addition of 0.3 equiv of acid,
21% of prerotor and 9% of rotor were generated, which
furthermore turned into 57% of prerotor and 39% of rotor upon
addition of 1.2 equiv of acid and eventually the rotor was fully
afforded upon addition of overall 2 equiv of TFA (Figure 5b).
This finding suggested that TFA first liberated zinc(II), whereas
formation of the pseudorotaxane rotator was rate-limiting.
Eventually, rotor formation was fueled by acid 6, which is
expected to initially provide the required protons for the self-
assembly of rotor 5. However, after decarboxylation, the strong
base 6A reclaimed the protons, enforcing disassembly of 5
(equation 1).
Figure 6. (a) Fluorescence spectra of prerotor, rotor, NetState-I and -II
(c = 1.1 × 10−5 M, CH2Cl2, λexc = 350 nm). (b) Off-equilibrium
transformation of prerotor [Zn(2)(3)(4)]2+ → rotor followed by
fluorescence changes at 579 nm vs time upon addition (red arrow) of
fuel 6. (c) Out-of-equilibrium transformation of NetState-I →
NetState-II documented by fluorescence changes at 579 nm vs time
upon addition (red arrow) of fuel 6. (d) Two fueled cycles of NetState-I
→ NetState-II → NetState-I monitored by 1H NMR.
ously for the first 14 min, suggesting a slow threading of 2·H+
into the prerotor (Figure 6b). Over the course of ca. 70 min, the
fluorescence intensity then decreased constantly (rotor →
prerotor), a process that was reproduced over five fuel cycles.
The full transformation NetState-I ⇆ NetState-II was first
followed by fluorescence spectrometry. After 2 equiv of acid 6
had been added to NetState-I (λem = 582 nm), the emission
intensity decreased drastically within the first minute (Figure
6c) suggesting rapid prerotor formation. Thereafter the
The fueled process was conveniently traceable by fluores-
cence spectroscopy (Figure 6a). Upon addition of one equiv of
fuel 6 to prerotor [Zn(2)(3)(4)]2+ (showing a weak emission at
λem = 579 nm), the fluorescence intensity increased continu-
5321
https://doi.org/10.1021/jacs.1c01948
J. Am. Chem. Soc. 2021, 143, 5319−5323

Journal of the American Chemical Society
pubs.acs.org/JACS
Communication
fluorescence intensity increased (1−20 min). In the beginning,
the increase may be explained by formation of the more
fluorescent rotor from the less fluorescent prerotor, whereas the
intermediate drop in the fluorescence intensity (20−75 min)
suggests decomposition of the rotor to prerotor. The ensuing
slow enhancement of the fluorescence intensity (75−342 min)
reflects the decomposition of the prerotor to NetState-I. Three
fuel cycles showed the high reproducibility (Figure 6c).
ACKNOWLEDGMENTS
■
We are highly indebted to the DFG (Schm 647/20-2) and to Dr.
T. Paululat of the University of Siegen. Dedicated to the memory
of Professor Siegfried Hu
̈
nig.
REFERENCES
■
(1) Kariyawasam, L. S.; Hartley, C. S. Dissipative Assembly of
Aqueous Carboxylic Acid Anhydrides Fueled by Carbodiimides. J. Am.
Chem. Soc. 2017, 139, 11949−11955.
(2) Wood, C. S.; Browne, C.; Wood, D. M.; Nitschke, J. R. Fuel-
Controlled Reassembly of Metal-Organic Architectures. ACS Cent. Sci.
2015, 1, 504−509.
(3) Fanlo-Virgós, H.; Alba, A.-N. R.; Hamieh, S.; Colomb-Delsuc, M.;
Otto, S. Transient Substrate-Induced Catalyst Formation in a Dynamic
Molecular Network. Angew. Chem., Int. Ed. 2014, 53, 11346−11350.
(4) Biagini, C.; Di Stefano, S. Abiotic Chemical Fuels for the
Operation of Molecular Machines. Angew. Chem., Int. Ed. 2020, 59,
8344−8354.
(5) Shi, Q.; Chen, C.-F. Step-by-step reaction-powered mechanical
motion triggered by a chemical fuel pulse. Chem. Sci. 2019, 10, 2529−
2533.
To get direct structural information about the fueled
NetState-I ⇆ NetState-II transformation, the process was
1
followed by H NMR using the signal of proton 10-H. The
spectra revealed rapid formation of the rotor with a maximum
(31%) reached after 6 min (Figure 6d); then the rotor amount
decreased. After 60 min, the rotor had fully decomposed into the
prerotor that over 300 min converted to free ligand 4 in
NetState-I. Clearly, the reverse Zn2+ translocation is much
slower than the initial zinc liberation after deprotonation of
ligand 2. Thus, in the forward direction, pseudorotaxane
formation was the slow step whereas in the reverse direction
the Zn2+ transport was slowest.
In conclusion, we demonstrate that the pseudorotaxane motif
is orthogonal to the HETTAP and Npy→ZnPor linkages,
allowing the integrative use of all these binding motifs to
generate a five-component rotor with an exchange frequency of
15.4 kHz (at room temperature). In contrast to fueled homo-
oligomeric assembly,10 the chemical fueling was instructed for
multitasking, instigating two kinetically distinct assembly and
disassembly steps in the dissipative rotor formation. Further
synchronization of fueled steps constitutes a vital challenge so
that complex molecular networks and machinery are efficiently
operated in an out-of-equilibrium manner using a single fuel.
(6) Ghosh, A.; Paul, I.; Adlung, M.; Wickleder, C.; Schmittel, M.
Oscillating Emission of [2]Rotaxane Driven by Chemical Fuel. Org.
Lett. 2018, 20, 1046−1049.
(7) Erbas-Cakmak, S.; Fielden, S. D. P.; Karaca, U.; Leigh, D. A.;
McTernan, C. T.; Tetlow, D. J.; Wilson, M. R. Rotary and linear
molecular motors driven by pulses of a chemical fuel. Science 2017, 358,
340−343.
̀
(8) Wilson, M. R.; Sola, J.; Carlone, A.; Goldup, S. M.; Lebrasseur, N.;
Leigh, D. A. An autonomous chemically fuelled small-molecule motor.
Nature 2016, 534, 235−240.
(9) Biagini, C.; Fielden, S. D. P.; Leigh, D. A.; Schaufelberger, F.; Di
Stefano, S.; Thomas, D. Dissipative Catalysis with a Molecular
Machine. Angew. Chem., Int. Ed. 2019, 58, 9876−9880.
(10) Singh, N.; Lainer, B.; Formon, G. J. M.; De Piccoli, S.; Hermans,
T. M. Re-programming Hydrogel Properties Using a Fuel-Driven
Reaction Cycle. J. Am. Chem. Soc. 2020, 142, 4083−4087.
(11) Rieß, B.; Grötsch, R. K.; Boekhoven, J. The Design of Dissipative
Molecular Assemblies Driven by Chemical Reaction Cycles. Chem.
2020, 6, 552−578.
ASSOCIATED CONTENT
■
sı
* Supporting Information
The Supporting Information is available free of charge at
https://pubs.acs.org/doi/10.1021/jacs.1c01948.
Synthetic procedures and full spectral characterization of
all new compounds, binding constants, and kinetic data
(PDF)
(12) Tena-Solsona, M.; Rieß, B.; Grötsch, R.; Löhrer, F.; Wanzke, C.;
Käsdorf, B.; Bausch, A.; Muller-Buschbaum, P.; Lieleg, O.; Boekhoven,
̈
J. Non-equilibrium dissipative supramolecular materials with a tunable
lifetime. Nat. Commun. 2017, 8, 15895.
(13) Dhiman, S.; Jain, A.; George, S. J. Transient Helicity: Fuel-Driven
Temporal Control over Conformational Switching in a Supramolecular
Polymer. Angew. Chem., Int. Ed. 2017, 56, 1329−1333.
AUTHOR INFORMATION
■
Corresponding Author
(14) Boekhoven, J.; Hendriksen, W. E.; Koper, G. J. M.; Eelkema, R.;
van Esch, J. H. Transient assembly of active materials fueled by a
chemical reaction. Science 2015, 349, 1075−1079.
Michael Schmittel − Center of Micro- and Nanochemistry and
Engineering, Organische Chemie I, Universität Siegen, D-
57068 Siegen, Germany; orcid.org/0000-0001-8622-
2883; Email: schmittel@chemie.uni-siegen.de
(15) Morrow, S. M.; Colomer, I.; Fletcher, S. P. A chemically fuelled
self-replicator. Nat. Commun. 2019, 10, 1011.
(16) Ragazzon, G.; Prins, L. J. Energy consumption in chemical fuel-
driven self-assembly. Nat. Nanotechnol. 2018, 13, 882−889.
(17) Mishra, A.; Korlepara, D. B.; Kumar, M.; Jain, A.; Jonnalagadda,
N.; Bejagam, K. K.; Balasubramanian, S.; George, S. J. Biomimetic
temporal self-assembly via fuel-driven controlled supramolecular
polymerization. Nat. Commun. 2018, 9, 1295.
Authors
Amit Ghosh − Center of Micro- and Nanochemistry and
Engineering, Organische Chemie I, Universität Siegen, D-
57068 Siegen, Germany
Indrajit Paul − Center of Micro- and Nanochemistry and
Engineering, Organische Chemie I, Universität Siegen, D-
57068 Siegen, Germany
(18) Ashkenasy, G.; Hermans, T. M.; Otto, S.; Taylor, A. F. Systems
chemistry. Chem. Soc. Rev. 2017, 46, 2543−2554.
(19) Maiti, S.; Fortunati, I.; Ferrante, C.; Scrimin, P.; Prins, L. J.
Biomimetic temporal self-assembly via fuel-driven controlled supra-
molecular polymerization. Nat. Chem. 2016, 8, 725−731.
(20) Goswami, A.; Saha, S.; Biswas, P. K.; Schmittel, M. (Nano)-
mechanical Motion Triggered by Metal Coordination: from Functional
Devices to Networked Multicomponent Catalytic Machinery. Chem.
Rev. 2020, 120, 125−199.
Complete contact information is available at:
https://pubs.acs.org/10.1021/jacs.1c01948
Notes
The authors declare no competing financial interest.
5322
https://doi.org/10.1021/jacs.1c01948
J. Am. Chem. Soc. 2021, 143, 5319−5323

Journal of the American Chemical Society
pubs.acs.org/JACS
Communication
(21) Sluysmans, D.; Stoddart, J. F. Growing community of artificial
molecular machinists. Proc. Natl. Acad. Sci. U. S. A. 2018, 115, 9359−
9361.
(22) Watson, M. A.; Cockroft, S. L. Man-made molecular machines:
membrane bound. Chem. Soc. Rev. 2016, 45, 6118−6129.
(23) Erbas-Cakmak, S.; Leigh, D. A.; McTernan, C. T.; Nussbaumer,
A. L. Artificial Molecular Machines. Chem. Rev. 2015, 115, 10081−
10206.
(41) He, Z.; Jiang, W.; Schalley, C. A. Integrative self-sorting: a
versatile strategy for the construction of complex supramolecular
architecture. Chem. Soc. Rev. 2015, 44, 779−789.
(42) Safont-Sempere, M. M.; Fernández, G.; Wurthner, F. Self-Sorting
̈
Phenomena in Complex Supramolecular Systems. Chem. Rev. 2011,
111, 5784−5814.
(43) Schmittel, M.; Kalsani, V.; Kishore, R. S. K.; Cölfen, H.; Bats, J.
W. Dynamic and Fluorescent Nanoscale Phenanthroline/Terpyridine
Zinc(II) Ladders. Self-Recognition in Unlike Ligand/Like Metal
Coordination Scenarios. J. Am. Chem. Soc. 2005, 127, 11544−11545.
(44) Saha, M. L.; De, S.; Pramanik, S.; Schmittel, M. Orthogonality in
discrete self-assembly - survey of current concepts. Chem. Soc. Rev.
2013, 42, 6860−6909.
(24) McConnell, A. J.; Wood, C. S.; Neelakandan, P. P.; Nitschke, J. R.
Stimuli-Responsive Metal-Ligand Assemblies. Chem. Rev. 2015, 115,
7729−7793.
(25) Schliwa, M.; Woehlke, G. Molecular motors. Nature 2003, 422,
759−765.
(45) Mandal, A. K.; Gangopadhyay, M.; Das, A. Photo-responsive
pseudorotaxanes and assemblies. Chem. Soc. Rev. 2015, 44, 663−676.
(26) Yoshida, M.; Muneyuki, E.; Hisabori, T. ATP Synthase-A
Marvellous Rotary Engine of the Cell. Nat. Rev. Mol. Cell Biol. 2001, 2,
669−677.
́
́
(46) Nicoli, F.; Paltrinieri, E.; Tranfic Bakic, M.; Baroncini, M.; Silvi,
S.; Credi, A. Binary logic operations with artificial molecular machines.
Coord. Chem. Rev. 2021, 428, 213589.
(27) Nakamura, M.; Kishimoto, K.; Kobori, Y.; Abe, T.; Yoza, K.;
Kobayashi, K. Self-Assembled Molecular Gear: A 4:1 Complex of
Rh(III)Cl Tetraarylporphyrin and Tetra(p-pyridyl)cavitand. J. Am.
Chem. Soc. 2016, 138, 12564−12577.
(47) Kwamen, C.; Niemeyer, J. Functional Rotaxanes in Catalysis.
Chem. - Eur. J. 2021, 27, 175−186.
(48) Xue, M.; Yang, Y.; Chi, X.; Yan, X.; Huang, F. Development of
Pseudorotaxanes and Rotaxanes: From Synthesis to Stimuli-Responsive
Motions to Applications. Chem. Rev. 2015, 115, 7398−7501.
(49) Paul, I.; Goswami, A.; Mittal, N.; Schmittel, M. Catalytic Three-
Component Machinery: Control of Catalytic Activity by Machine
Speed. Angew. Chem., Int. Ed. 2018, 57, 354−358.
(28) Takara, Y.; Kusamoto, T.; Masui, T.; Nishikawa, M.; Kume, S.;
Nishihara, H. A single-molecular twin rotor: correlated motion of two
pyrimidine rings coordinated to copper. Chem. Commun. 2015, 51,
2896−2898.
(29) Scottwell, S. ø.; Elliott, A. B. S.; Shaffer, K. J.; Nafady, A.;
McAdam, C. J.; Gordon, K. C.; Crowley, J. D. Chemically and
electrochemically induced expansion and contraction of a ferrocene
rotor. Chem. Commun. 2015, 51, 8161−8164.
(50) Saha, S.; Ghosh, A.; Paululat, T.; Schmittel, M. Dalton Trans.
2020, 49, 8693−8700.
(30) Nishikawa, M.; Kume, S.; Nishihara, H. Stimuli-responsive
pyrimidine ring rotation in copper complexes for switching their
physical properties. Phys. Chem. Chem. Phys. 2013, 15, 10549−10565.
(31) Shibata, M.; Tanaka, S.; Ikeda, T.; Shinkai, S.; Kaneko, K.; Ogi,
S.; Takeuchi, M. Stimuli-responsive Folding and Unfolding of a
Polymer Bearing Multiple cerium(IV) Bis(porphyrinate) Joints:
Mechano-Imitation of the Action of a Folding Ruler. Angew. Chem.,
Int. Ed. 2013, 52, 397−400.
(32) Ogi, S.; Ikeda, T.; Wakabayashi, R.; Shinkai, S.; Takeuchi, M. A
Bevel-Gear-Shaped Rotor Bearing a Double-Decker Porphyrin
Complex. Chem. - Eur. J. 2010, 16, 8285−8290.
(33) Hiraoka, S.; Hisanaga, Y.; Shiro, M.; Shionoya, M. A Molecular
Double Ball Bearing: An Ag(I)-Pt(II) Dodecanuclear Quadruple-
Decker Complex With Three Rotors. Angew. Chem., Int. Ed. 2010, 49,
1669−1673.
(34) Hiraoka, S.; Okuno, E.; Tanaka, T.; Shiro, M.; Shionoya, M.
Ranging Correlated Motion (1.5 nm) of Two Coaxially Arranged
Rotors Mediated by Helix Inversion of a Supramolecular Transmitter. J.
Am. Chem. Soc. 2008, 130, 9089−9098.
(35) Saha, M. L.; Neogi, S.; Schmittel, M. Dynamic heteroleptic metal-
phenanthroline complexes: from structure to function. Dalton Trans.
2014, 43, 3815−3834.
(36) Biswas, P.; Saha, S.; Paululat, T.; Schmittel, M. Rotating Catalysts
Are Superior: Suppressing Product Inhibition by Anchimeric
Assistance in Four-Component Catalytic Machinery. J. Am. Chem.
Soc. 2018, 140, 9038−9041.
(37) Biswas, P.; Saha, S.; Gaikwad, S.; Schmittel, M. Reversible
Multicomponent AND Gate Triggered by Stoichiometric Chemical
Pulses Commands the Self-Assembly and Actuation of Catalytic
Machinery. J. Am. Chem. Soc. 2020, 142, 7889−7897.
(38) Goswami, A.; Paululat, T.; Schmittel, M. Switching Dual
Catalysis without Molecular Switch: Using A Multicomponent
Information System for Reversible Reconfiguration of Catalytic
Machinery. J. Am. Chem. Soc. 2019, 141, 15656−15663.
(39) Ghosh, A.; Paul, I.; Schmittel, M. Time-Dependent Pulses of
Lithium Ions in Cascaded Signaling and Out-of-Equilibrium (Supra)-
molecular Logic. J. Am. Chem. Soc. 2019, 141, 18954−18957.
(40) Berrocal, J. A.; Biagini, C.; Mandolini, L.; Di Stefano, S. Coupling
of the Decarboxylation of 2-Cyano-2-phenylpropanoic Acid to Large-
Amplitude Motions: A Convenient Fuel for an Acid-Base-Operated
Molecular Switch. Angew. Chem., Int. Ed. 2016, 55, 6997−7001.
5323
https://doi.org/10.1021/jacs.1c01948
J. Am. Chem. Soc. 2021, 143, 5319−5323