Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

A molecular information ratchet

Abstract

Motor proteins and other biological machines are highly efficient at converting energy into directed motion and driving chemical systems away from thermodynamic equilibrium1. But even though these biological structures have inspired the design of many molecules that mimic aspects of their behaviour2,3,4,5,6,7,8,9,10,11,12,13,14,15, artificial nanomachine systems operate almost exclusively by moving towards thermodynamic equilibrium, not away from it. Here we show that information about the location of a macrocycle in a rotaxane—a molecular ring threaded onto a molecular axle—can be used, on the input of light energy, to alter the kinetics of the shuttling of the macrocycle between two compartments on the axle. For an ensemble of such molecular machines, the macrocycle distribution is directionally driven away from its equilibrium value without ever changing the relative binding affinities of the ring for the different parts of the axle. The selective transport of particles between two compartments by brownian motion in this way bears similarities to the hypothetical task performed without an energy input by a ‘demon’ in Maxwell’s famous thought experiment16,17,18,19. Our observations demonstrate that synthetic molecular machines can operate by an information ratchet mechanism20,21,22, in which knowledge of a particle’s position is used to control its transport away from equilibrium.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: A photo-operated molecular information ratchet.
Figure 2: 1 H NMR spectra (600 MHz, CD 3 OD, 298 K) of a working nanomachine.
Figure 3: Operation of a molecular information ratchet.
Figure 4: Operation of rotaxane 2, featuring only intermolecular photosensitization of the α-methyl stilbene gate.

References

  1. Schliwa, M. (ed.) Molecular Motors (Wiley-VCH, Weinheim, 2003)

    Google Scholar 

  2. Bissell, R. A., Córdova, E., Kaifer, A. E. & Stoddart, J. F. A chemically and electrochemically switchable molecular shuttle. Nature 369, 133–137 (1994)

    ADS  CAS  Article  Google Scholar 

  3. Kelly, T. R., De Silva, H. & Silva, R. A. Unidirectional rotary motion in a molecular system. Nature 401, 150–152 (1999)

    ADS  CAS  Article  Google Scholar 

  4. Koumura, N., Zijlstra, R. W. J., van Delden, R. A., Harada, N. & Feringa, B. L. Light-driven monodirectional molecular rotor. Nature 401, 152–155 (1999)

    ADS  CAS  Article  Google Scholar 

  5. Brouwer, A. M. et al. Photoinduction of fast, reversible translational motion in a hydrogen-bonded molecular shuttle. Science 291, 2124–2128 (2001)

    ADS  CAS  Article  Google Scholar 

  6. Leigh, D. A., Wong, J. K. Y., Dehez, F. & Zerbetto, F. Unidirectional rotation in a mechanically interlocked molecular rotor. Nature 424, 174–179 (2003)

    ADS  CAS  Article  Google Scholar 

  7. Thordarson, P., Bijsterveld, E. J. A., Rowan, A. E. & Nolte, R. J. M. Epoxidation of polybutadiene by a topologically linked catalyst. Nature 424, 915–918 (2003)

    ADS  CAS  Article  Google Scholar 

  8. Badjić, J. D., Balzani, V., Credi, A., Silvi, S. & Stoddart, J. F. A molecular elevator. Science 303, 1845–1849 (2004)

    ADS  Article  Google Scholar 

  9. Hernández, J. V., Kay, E. R. & Leigh, D. A. A reversible synthetic rotary molecular motor. Science 306, 1532–1537 (2004)

    ADS  Article  Google Scholar 

  10. Fletcher, S. P., Dumur, F., Pollard, M. M. & Feringa, B. L. A reversible, unidirectional molecular rotary motor driven by chemical energy. Science 310, 80–82 (2005)

    ADS  CAS  Article  Google Scholar 

  11. Liu, Y. et al. Linear artificial molecular muscles. J. Am. Chem. Soc. 127, 9745–9759 (2005)

    CAS  Article  Google Scholar 

  12. Berná, J. et al. Macroscopic transport by synthetic molecular machines. Nature Mater. 4, 704–710 (2005)

    ADS  Article  Google Scholar 

  13. Shirai, Y., Osgood, A. J., Zhao, Y., Kelly, K. F. & Tour, J. M. Directional control in thermally driven single-molecule nanocars. Nano Lett. 5, 2330–2334 (2005)

    ADS  CAS  Article  Google Scholar 

  14. Eelkema, R. et al. Molecular machines: Nanomotor rotates microscale objects. Nature 440, 163 (2006)

    ADS  CAS  Article  Google Scholar 

  15. Muraoka, T., Kinbara, K. & Aida, T. Mechanical twisting of a guest by a photoresponsive host. Nature 440, 512–515 (2006)

    ADS  CAS  Article  Google Scholar 

  16. Maxwell, J. C. Letter to P. G. Tait, 11 December 1867. Reproduced in The Scientific Letters and Papers of James Clerk Maxwell Vol. II, 1862–1873 (ed. Harman, P. M.) 331–332 (Cambridge Univ. Press, Cambridge, UK, 1995)

    Google Scholar 

  17. Maxwell, J. C. Theory of Heat Ch. 22 (Longmans, Green and Co., London, 1871)

    Google Scholar 

  18. Maxwell, J. C. Letter to P. G. Tait, circa. 1875. Reproduced in The Scientific Letters and Papers of James Clerk Maxwell Vol. III, 1874–1879 (ed. Harman, P. M.) 185–187 (Cambridge Univ. Press, Cambridge, UK, 2002)

    Google Scholar 

  19. Leff, H. S. & Rex, A. F. Maxwell’s Demon 2. Entropy, Classical and Quantum Information, Computing (Institute of Physics Publishing, Bristol, 2003)

    Google Scholar 

  20. Astumian, R. D. & Derényi, I. Fluctuation driven transport and models of molecular motors and pumps. Eur. Biophys. J. 27, 474–489 (1998)

    CAS  Article  Google Scholar 

  21. Parmeggiani, A., Jülicher, F., Ajdari, A. & Prost, J. Energy transduction of isothermal ratchets: Generic aspects and specific examples close to and far from equilibrium. Phys. Rev. E 60, 2127–2140 (1999)

    ADS  CAS  Article  Google Scholar 

  22. Parrondo, J. M. R. & De Cisneros, B. J. Energetics of Brownian motors: A review. Appl. Phys. A 75, 179–191 (2002)

    ADS  CAS  Article  Google Scholar 

  23. Tokunaga, Y., Akasaka, K., Hisada, K., Shimomura, Y. & Kakuchi, S. A rotaxane synthesis based on stilbene photoisomerization. A photoswitchable catch and release process. Chem. Commun. 2250–2251 (2003)

  24. Kolchinski, A. G., Busch, D. H. & Alcock, N. W. Gaining control over molecular threading: benefits of second coordination sites and aqueous–organic interfaces in rotaxane synthesis. J. Chem. Soc. Chem. Commun. 1289–1291 (1995)

  25. Ashton, P. R. et al. Dialkylammonium ion/crown ether complexes: the forerunners of a new family of interlocked molecules. Angew. Chem. Int. Edn Engl. 34, 1865–1869 (1995)

    CAS  Article  Google Scholar 

  26. Hammond, G. S. et al. Mechanisms of photochemical reactions in solution. XXII. Photochemical cistrans isomerization. J. Am. Chem. Soc. 86, 3197–3217 (1964)

    CAS  Article  Google Scholar 

  27. Bennett, C. H. The thermodynamics of computation – a review. Int. J. Theor. Phys. 21, 905–940 (1982)

    CAS  Article  Google Scholar 

  28. Chatterjee, M. N., Kay, E. R. & Leigh, D. A. Beyond switches: ratcheting a particle energetically uphill with a compartmentalized molecular machine. J. Am. Chem. Soc. 128, 4058–4073 (2006)

    CAS  Article  Google Scholar 

  29. Kay, E. R. & Leigh, D. A. Lighting up nanomachines. Nature 440, 286–287 (2006)

    ADS  CAS  Article  Google Scholar 

  30. Reimann, P. Brownian motors: Noisy transport far from equilibrium. Phys. Rep. 361, 57–265 (2002)

    ADS  MathSciNet  CAS  Article  Google Scholar 

Download references

Acknowledgements

We thank P. J. Camp and his research group for the free energy calculation, and the EPSRC, the EU project Hy3M and the Carnegie Trust for financial support. D.A.L. is an EPSRC Senior Research Fellow and holds a Royal Society-Wolfson research merit award.

Author Contributions V.S., C.-F.L. and E.R.K. contributed equally to this work.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to David A. Leigh.

Ethics declarations

Competing interests

Reprints and permissions information is available at www.nature.com/reprints. The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Notes and Supplementary Figures S1-S7 with legends and additional references. The file contains details of synthetic procedures for the preparation of thread and rotaxane molecules, the results from a repeat run of the photochemical experiments carried out on rotaxane 1, and a Supplementary Figure containing the 1H NMR spectra relevant to the experiment on control rotaxane 2 (reported in Fig. 4 of the main text). Also included are the results of photochemical experiments carried on model compounds and a discussion of these in relation to the kinetic mechanism of operation of the molecular machine. Explanatory notes are also provided in relation to the effect of stilbene isomerization on the macrocycle binding affinities for the ammonium sites and the calculation of the extent to which the molecular machine is moved away from equilibrium. (PDF 1674 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Serreli, V., Lee, CF., Kay, E. et al. A molecular information ratchet. Nature 445, 523–527 (2007). https://doi.org/10.1038/nature05452

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature05452

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing