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Electrostatic catalysis of a Diels–Alder reaction

Abstract

It is often thought that the ability to control reaction rates with an applied electrical potential gradient is unique to redox systems. However, recent theoretical studies suggest that oriented electric fields could affect the outcomes of a range of chemical reactions, regardless of whether a redox system is involved1,2,3,4. This possibility arises because many formally covalent species can be stabilized via minor charge-separated resonance contributors. When an applied electric field is aligned in such a way as to electrostatically stabilize one of these minor forms, the degree of resonance increases, resulting in the overall stabilization of the molecule or transition state. This means that it should be possible to manipulate the kinetics and thermodynamics of non-redox processes using an external electric field, as long as the orientation of the approaching reactants with respect to the field stimulus can be controlled. Here, we provide experimental evidence that the formation of carbon–carbon bonds is accelerated by an electric field. We have designed a surface model system to probe the Diels–Alder reaction, and coupled it with a scanning tunnelling microscopy break-junction approach5,6,7. This technique, performed at the single-molecule level, is perfectly suited to deliver an electric-field stimulus across approaching reactants. We find a fivefold increase in the frequency of formation of single-molecule junctions, resulting from the reaction that occurs when the electric field is present and aligned so as to favour electron flow from the dienophile to the diene. Our results are qualitatively consistent with those predicted by quantum-chemical calculations in a theoretical model of this system, and herald a new approach to chemical catalysis.

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Figure 1: Electrostatic catalysis of a Diels–Alder reaction.
Figure 2: Computational modelling of the Diels–Alder reaction.
Figure 3: Blinking experiments.
Figure 4: Frequency of blinks (junctions) as a function of the applied bias.

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References

  1. Meir, R., Chen, H., Lai, W. & Shaik, S. Oriented electric fields accelerate Diels–Alder reactions and control the endo/exo selectivity. ChemPhysChem 11, 301–310 (2010)

    Article  CAS  Google Scholar 

  2. Gryn’ova, G., Marshall, D. L., Blanksby, S. J. & Coote, M. L. Switching radical stability by pH-induced orbital conversion. Nature Chem. 5, 474–481 (2013)

    Article  ADS  Google Scholar 

  3. Gryn’ova, G. & Coote, M. L. Origin and scope of long-range stabilizing interactions and associated SOMO–HOMO conversion in distonic radical anions. J. Am. Chem. Soc. 135, 15392–15403 (2013)

    Article  Google Scholar 

  4. Shaik, S., de Visser, S. P. & Kumar, D. External electric field will control the selectivity of enzymatic-like bond activations. J. Am. Chem. Soc. 126, 11746–11749 (2004)

    Article  CAS  Google Scholar 

  5. Xu, B. & Tao, N. J. Measurement of single-molecule resistance by repeated formation of molecular junctions. Science 301, 1221–1223 (2003)

    Article  ADS  CAS  Google Scholar 

  6. Haiss, W. et al. Measurement of single molecule conductivity using the spontaneous formation of molecular wires. Phys. Chem. Chem. Phys. 6, 4330–4337 (2004)

    Article  CAS  Google Scholar 

  7. Haiss, W. et al. Precision control of single-molecule electrical junctions. Nature Mater. 5, 995–1002 (2006)

    Article  ADS  CAS  Google Scholar 

  8. Sini, G., Maitre, P., Hiberty, P. C. & Shaik, S. S. Covalent, ionic and resonating single bonds. J. Mol. Struct. Theochem 229, 163–188 (1991)

    Article  Google Scholar 

  9. Shaik, S., Danovich, D., Wu, W. & Hiberty, P. C. Charge-shift bonding and its manifestations in chemistry. Nature Chem. 1, 443–449 (2009)

    Article  ADS  CAS  Google Scholar 

  10. Shurki, A., Hiberty, P. C. & Shaik, S. Charge-shift bonding in group IVB halides: a valence bond study of MH3−Cl (M = C, Si, Ge, Sn, Pb) molecules. J. Am. Chem. Soc. 121, 822–834 (1999)

    Article  CAS  Google Scholar 

  11. Fischer, H. & Radom, L. Factors controlling the addition of carbon-centered radicals to alkenes—an experimental and theoretical perspective. Angew. Chem. Int. Edn 40, 1340–1371 (2001)

    Article  CAS  Google Scholar 

  12. Lai, W., Li, C., Chen, H. & Shaik, S. Hydrogen-abstraction reactivity patterns from A to Y: the valence bond way. Angew. Chem. Int. Edn 51, 5556–5578 (2012)

    Article  CAS  Google Scholar 

  13. Warshel, A. et al. Electrostatic basis for enzyme catalysis. Chem. Rev. 106, 3210–3235 (2006)

    Article  CAS  Google Scholar 

  14. Hirao, H., Chen, H., Carvajal, M. A., Wang, Y. & Shaik, S. Effect of external electric fields on the C–H bond activation reactivity of nonheme iron–oxo reagents. J. Am. Chem. Soc. 130, 3319–3327 (2008)

    Article  CAS  Google Scholar 

  15. Lai, W., Chen, H., Cho, K.-B. & Shaik, S. External electric field can control the catalytic cycle of cytochrome P450cam: a QM/MM Study. J. Phys. Chem. Lett. 1, 2082–2087 (2010)

    Article  CAS  Google Scholar 

  16. Fried, S. D., Bagchi, S. & Boxer, S. G. Extreme electric fields power catalysis in the active site of ketosteroid isomerase. Science 346, 1510–1514 (2014)

    Article  ADS  CAS  Google Scholar 

  17. Klinska, M., Smith, L. M., Gryn’ova, G., Banwell, M. G. & Coote, M. L. Experimental demonstration of pH-dependent electrostatic catalysis of radical reactions. Chem. Sci. 6, 5623–5627 (2015)

    Article  CAS  Google Scholar 

  18. Franchi, P., Mezzina, E. & Lucarini, M. SOMO–HOMO conversion in distonic radical anions: an experimental test in solution by EPR radical equilibration technique. J. Am. Chem. Soc. 136, 1250–1252 (2014)

    Article  CAS  Google Scholar 

  19. Alemani, M. et al. Electric field-induced isomerization of azobenzene by STM. J. Am. Chem. Soc. 128, 14446–14447 (2006)

    Article  CAS  Google Scholar 

  20. Gorin, C. F., Beh, E. S. & Kanan, M. W. An electric field-induced change in the selectivity of a metal oxide-catalyzed epoxide rearrangement. J. Am. Chem. Soc. 134, 186–189 (2012)

    Article  CAS  Google Scholar 

  21. Nicolaou, K. C., Snyder, S. A., Montagnon, T. & Vassilikogiannakis, G. The Diels–Alder reaction in total synthesis. Angew. Chem. Int. Edn 41, 1668–1698 (2002)

    Article  CAS  Google Scholar 

  22. Paddon-Row, M. N. Investigating long-range electron-transfer processes with rigid, covalently linked donor-(norbornylogous bridge)-acceptor systems. Acc. Chem. Res. 27, 18–25 (1994)

    Article  CAS  Google Scholar 

  23. Darwish, N., Paddon-Row, M. N. & Gooding, J. J. Surface-bound norbornylogous bridges as molecular rulers for investigating interfacial electrochemistry and as single molecule switches. Acc. Chem. Res. 47, 385–395 (2014)

    Article  CAS  Google Scholar 

  24. Darwish, N. et al. Observation of electrochemically controlled quantum interference in a single anthraquinone-based norbornylogous bridge molecule. Angew. Chem. Int. Edn 51, 3203–3206 (2012)

    Article  CAS  Google Scholar 

  25. Darwish, N. et al. Probing the effect of the solution environment around redox-active moieties using rigid anthraquinone terminated molecular rulers. J. Am. Chem. Soc. 134, 18401–18409 (2012)

    Article  CAS  Google Scholar 

  26. Darwish, N. et al. Electroactive self-assembled monolayers of unique geometric structures by using rigid norbornylogous bridges. Chemistry 18, 283–292 (2012)

    Article  CAS  Google Scholar 

  27. Díez-Pérez, I. et al. Rectification and stability of a single molecular diode with controlled orientation. Nature Chem. 1, 635–641 (2009)

    Article  ADS  Google Scholar 

  28. Donhauser, Z. J. et al. Conductance switching in single molecules through conformational changes. Science 292, 2303–2307 (2001)

    Article  CAS  Google Scholar 

  29. Claridge, S. A., Schwartz, J. J. & Weiss, P. S. Electrons, photons, and force: quantitative single-molecule measurements from physics to biology. ACS Nano 5, 693–729 (2011)

    Article  CAS  Google Scholar 

  30. Tao, N. J. Electron transport in molecular junctions. Nature Nanotechnol. 1, 173–181 (2006)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

This research was supported by the MINECO Spanish National Project (no. CTQ2012-36090) and an EU Reintegration Grant (FP7-PEOPLE-2010-RG-277182), and by resources provided at the NCI National Facility systems at the Australian National University through the National Computational Merit Allocation Scheme, supported by the Australian Government. N.D. thanks the European Union for a Marie Curie IIF Fellowship. I.D.-P. thanks the Ramon y Cajal program (MINECO, no. RYC-2011-07951) for financial support. S.C. thanks the University of Wollongong for a Vice Chancellor Fellowship, and the Australian National Fabrication Facility for financial support. A.C.A. thanks the Spanish Ministerio de Educación for an FPU fellowship. M.L.C acknowledges financial support from the Australian Research Council (ARC) and an ARC Future Fellowship, and discussions with M. Banwell. We also acknowledge funding from the ARC Centre of Excellence Scheme (project no. CE 140100012).

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Authors

Contributions

A.C.A., N.D. and I.D.-P. carried out the STM experiments and analysed the data. N.J.B. and N.L.H. performed the quantum-chemical modelling, with input from M.L.C. S.C. carried out the synthetic work. All authors conceived the work, and designed and discussed the experiments. M.L.C. and S.C. wrote the manuscript, with substantial contributions from the other authors.

Corresponding authors

Correspondence to Nadim Darwish, Simone Ciampi, Ismael Diez-Perez or Michelle L. Coote.

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The authors declare no competing financial interests.

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Aragonès, A., Haworth, N., Darwish, N. et al. Electrostatic catalysis of a Diels–Alder reaction. Nature 531, 88–91 (2016). https://doi.org/10.1038/nature16989

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