The photochemical ring-opening of 1,3-cyclohexadiene imaged by ultrafast electron diffraction

Abstract

The ultrafast photoinduced ring-opening of 1,3-cyclohexadiene constitutes a textbook example of electrocyclic reactions in organic chemistry and a model for photobiological reactions in vitamin D synthesis. Although the relaxation from the photoexcited electronic state during the ring-opening has been investigated in numerous studies, the accompanying changes in atomic distance have not been resolved. Here we present a direct and unambiguous observation of the ring-opening reaction path on the femtosecond timescale and subångström length scale using megaelectronvolt ultrafast electron diffraction. We followed the carbon–carbon bond dissociation and the structural opening of the 1,3-cyclohexadiene ring by the direct measurement of time-dependent changes in the distribution of interatomic distances. We observed a substantial acceleration of the ring-opening motion after internal conversion to the ground state due to a steepening of the electronic potential gradient towards the product minima. The ring-opening motion transforms into rotation of the terminal ethylene groups in the photoproduct 1,3,5-hexatriene on the subpicosecond timescale.

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Fig. 1: Schematic of the photoinduced ring-opening reaction of CHD.
Fig. 2: Comparison of experimental and simulated atomic PDFs.
Fig. 3: Comparison of experimental and simulated time-dependent ΔPDFs.
Fig. 4: Comparison between experimental and simulated delay in rise time between peaks α, β and γ.

Data availability

The data that support the findings of this study are available from the corresponding authors upon reasonable request.

Code availability

The codes used for the analysis of the raw experimental and simulation data and for the generation of the manuscript figures are available from the corresponding authors upon reasonable request. TeraChem is a proprietary quantum chemistry software suite developed by T. Martínez and is available via the proper license set forth by © PetaChem, LLC.

References

  1. 1.

    Arruda, B. C. & Sension, R. J. Ultrafast polyene dynamics: the ring opening of 1,3-cyclohexadiene derivatives. Phys. Chem. Chem. Phys. 16, 4439–4455 (2014).

    CAS  Article  Google Scholar 

  2. 2.

    Havinga, E. & Schlatmann, J. L. M. A. Remarks on the specificities of the photochemical and thermal transformations in the vitamin D field. Tetrahedron 16, 146–152 (1961).

    Article  Google Scholar 

  3. 3.

    Woodward, R. B. & Hoffmann, R. The conservation of orbital symmetry. Angew. Chem. Int. Ed. 8, 781–853 (1969).

    CAS  Article  Google Scholar 

  4. 4.

    Bach, T. & Hehn, J. P. Photochemical reactions as key steps in natural product synthesis. Angew. Chem. Int. Ed. 50, 1000–1045 (2011).

    CAS  Article  Google Scholar 

  5. 5.

    Irie, M. Diarylethenes for memories and switches. Chem. Rev. 100, 1685–1716 (2000).

    CAS  Article  Google Scholar 

  6. 6.

    Deb, S. & Weber, P. M. The ultrafast pathway of photon-induced electrocyclic ring-opening reactions: the case of 1,3-cyclohexadiene. Annu. Rev. Phys. Chem. 62, 19–39 (2011).

    CAS  Article  Google Scholar 

  7. 7.

    Hofmann, A. & de Vivie-Riedle, R. Quantum dynamics of photoexcited cyclohexadiene introducing reactive coordinates. J. Chem. Phys. 112, 5054–5059 (2000).

    CAS  Article  Google Scholar 

  8. 8.

    Celani, P., Ottani, S., Olivucci, M., Bernardi, F. & Robb, M. A. What happens during the picosecond lifetime of 2A1 cyclohexa-1,3-diene? A CAS-SCF study of the cyclohexadiene/hexatriene photochemical interconversion. J. Am. Chem. Soc. 116, 10141–10151 (1994).

    CAS  Article  Google Scholar 

  9. 9.

    Ruan, C.-Y. et al. Ultrafast diffraction and structural dynamics: the nature of complex molecules far from equilibrium. Proc. Natl Acad. Sci. USA 98, 7117–7122 (2001).

    CAS  Article  Google Scholar 

  10. 10.

    Pullen, S. H., Anderson, N. A., Walker, L. A. & Sension, R. J. The ultrafast photochemical ring-opening reaction of 1,3-cyclohexadiene in cyclohexane. J. Chem. Phys. 108, 556–563 (1998).

    CAS  Article  Google Scholar 

  11. 11.

    Cardoza, J. D., Dudek, R. C., Mawhorter, R. J. & Weber, P. M. Centering of ultrafast time-resolved pump–probe electron diffraction patterns. Chem. Phys. 299, 307–312 (2004).

    CAS  Article  Google Scholar 

  12. 12.

    Attar, A. R. et al. Femtosecond X-ray spectroscopy of an electrocyclic ring-opening reaction. Science 356, 54–59 (2017).

    CAS  Article  Google Scholar 

  13. 13.

    Adachi, S., Sato, M. & Suzuki, T. Direct observation of ground-state product formation in a 1,3-cyclohexadiene ring-opening reaction. J. Phys. Chem. Lett. 6, 343–346 (2015).

    CAS  Article  Google Scholar 

  14. 14.

    Pemberton, C. C., Zhang, Y., Saita, K., Kirrander, A. & Weber, P. M. From the (1B) spectroscopic state to the photochemical product of the ultrafast ring-opening of 1,3-cyclohexadiene: a spectral observation of the complete reaction path. J. Phys. Chem. A 119, 8832–8845 (2015).

    CAS  Article  Google Scholar 

  15. 15.

    Kotur, M., Weinacht, T., Pearson, B. J. & Matsika, S. Closed-loop learning control of isomerization using shaped ultrafast laser pulses in the deep ultraviolet. J. Chem. Phys. 130, 134311 (2009).

    Article  Google Scholar 

  16. 16.

    Wolf, T. J. A. et al. Probing ultrafast ππ*/* internal conversion in organic chromophores via K-edge resonant absorption. Nat. Commun. 8, 29 (2017).

    CAS  Article  Google Scholar 

  17. 17.

    Stolow, A. & Underwood, J.G. Time-resolved photoelectron spectroscopy of nonadiabatic dynamics in polyatomic molecules. Adv. Chem. Phys. 139, 497–587 (2008).

    CAS  Google Scholar 

  18. 18.

    Herbst, J., Heyne, K. & Diller, R. Femtosecond infrared spectroscopy of bacteriorhodopsin chromophore isomerization. Science 297, 822–825 (2002).

    CAS  Article  Google Scholar 

  19. 19.

    Ihee, H. et al. Direct imaging of transient molecular structures with ultrafast diffraction. Science 291, 458–462 (2001).

    CAS  Article  Google Scholar 

  20. 20.

    Srinivasan, R., Lobastov, V. A., Ruan, C.-Y. & Zewail, A. H. Ultrafast electron diffraction (UED). Helv. Chim. Acta 86, 1761–1799 (2003).

    Article  Google Scholar 

  21. 21.

    Minitti, M. P. et al. Imaging molecular motion: femtosecond X-ray scattering of an electrocyclic chemical reaction. Phys. Rev. Lett. 114, 255501 (2015).

    CAS  Article  Google Scholar 

  22. 22.

    Dudek, R. C. & Weber, P. M. Ultrafast diffraction imaging of the electrocyclic ring-opening reaction of 1,3-cyclohexadiene. J. Phys. Chem. A 105, 4167–4171 (2001).

    CAS  Article  Google Scholar 

  23. 23.

    Küpper, J. et al. X-ray diffraction from isolated and strongly aligned gas-phase molecules with a free-electron laser. Phys. Rev. Lett. 112, 083002 (2014).

    Article  Google Scholar 

  24. 24.

    Jean-Ruel, H. et al. Ring-closing reaction in diarylethene captured by femtosecond electron crystallography. J. Phys. Chem. B 117, 15894–15902 (2013).

    CAS  Article  Google Scholar 

  25. 25.

    Ischenko, A. A., Weber, P. M. & Miller, R. J. D. Capturing chemistry in action with electrons: realization of atomically resolved reaction dynamics. Chem. Rev. 117, 11066–11124 (2017).

    CAS  Article  Google Scholar 

  26. 26.

    Gao, M. et al. Mapping molecular motions leading to charge delocalization with ultrabright electrons. Nature 496, 343–346 (2013).

    CAS  Article  Google Scholar 

  27. 27.

    Zimmerman, H. E. & Nesterov, E. E. Development of experimental and theoretical crystal lattice organic photochemistry: the quantitative cavity. Mechanistic and exploratory organic photochemistry Acc. Chem. Res. 35, 77–85 (2002).

    CAS  Article  Google Scholar 

  28. 28.

    Zimmerman, H. E. & Zuraw, M. J. Photochemistry in a box. Photochemical reactions of molecules entrapped in crystal lattices: mechanistic and exploratory organic photochemistry. J. Am. Chem. Soc. 111, 7974–7989 (1989).

    CAS  Article  Google Scholar 

  29. 29.

    Yang, J. et al. Diffractive imaging of a rotational wavepacket in nitrogen molecules with femtosecond megaelectronvolt electron pulses. Nat. Commun. 7, 11232 (2016).

    CAS  Article  Google Scholar 

  30. 30.

    Yang, J. et al. Diffractive imaging of coherent nuclear motion in isolated molecules. Phys. Rev. Lett. 117, 153002 (2016).

    Article  Google Scholar 

  31. 31.

    Yang, J. et al. Imaging CF3I conical intersection and photodissociation dynamics with ultrafast electron diffraction. Science 361, 64–67 (2018).

    CAS  Article  Google Scholar 

  32. 32.

    Kirrander, A. & Weber, P. M. Fundamental limits on spatial resolution in ultrafast X-ray diffraction. Appl. Sci. 7, 534 (2017).

    Article  Google Scholar 

  33. 33.

    Ben-Nun, M., Quenneville, J. & Martínez, T. J. Ab Initio multiple spawning: photochemistry from first principles quantum molecular dynamics. J. Phys. Chem. A 104, 5161–5175 (2000).

    CAS  Article  Google Scholar 

  34. 34.

    Snyder, J. W., Parrish, R. M. & Martínez, T. J. α-CASSCF: an efficient, empirical correction for SA-CASSCF to closely approximate MS-CASPT2 potential energy surfaces. J. Phys. Chem. Lett. 8, 2432–2437 (2017).

    CAS  Article  Google Scholar 

  35. 35.

    Kosma, K., Trushin, S. A., Fuss, W. & Schmid, W. E. Cyclohexadiene ring opening observed with 13 fs resolution: coherent oscillations confirm the reaction path. Phys. Chem. Chem. Phys. 11, 172–181 (2009).

    CAS  Article  Google Scholar 

  36. 36.

    Kuthirummal, N., Rudakov, F. M., Evans, C. L. & Weber, P. M. Spectroscopy and femtosecond dynamics of the ring opening reaction of 1,3-cyclohexadiene. J. Chem. Phys. 125, 133307 (2006).

    Article  Google Scholar 

  37. 37.

    Harris, D. A., Orozco, M. B. & Sension, R. J. Solvent dependent conformational relaxation of cis-1,3,5-hexatriene. J. Phys. Chem. A 110, 9325–9333 (2006).

    CAS  Article  Google Scholar 

  38. 38.

    Weathersby, S. P. et al. Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory. Rev. Sci. Instrum. 86, 073702 (2015).

    CAS  Article  Google Scholar 

  39. 39.

    Hohenstein, E. G., Luehr, N., Ufimtsev, I. S. & Martínez, T. J. An atomic orbital-based formulation of the complete active space self-consistent field method on graphical processing units. J. Chem. Phys. 142, 224103 (2015).

    Article  Google Scholar 

  40. 40.

    Snyder, J. W., Hohenstein, E. G., Luehr, N. & Martínez, T. J. An atomic orbital-based formulation of analytical gradients and nonadiabatic coupling vector elements for the state-averaged complete active space self-consistent field method on graphical processing units. J. Chem. Phys. 143, 154107 (2015).

    Article  Google Scholar 

  41. 41.

    Snyder, J. W., Fales, B. S., Hohenstein, E. G., Levine, B. G. & Martínez, T. J. A direct-compatible formulation of the coupled perturbed complete active space self-consistent field equations on graphical processing units. J. Chem. Phys. 146, 174113 (2017).

    Article  Google Scholar 

  42. 42.

    Snyder, J. W., Curchod, B. F. E. & Martínez, T. J. GPU-accelerated state-averaged complete active space self-consistent field interfaced with ab initio multiple spawning unravels the photodynamics of provitamin D3. J. Phys. Chem. Lett. 7, 2444–2449 (2016).

    CAS  Article  Google Scholar 

  43. 43.

    Roos, B. O. The complete active space self-consistent field method and its applications in electronic structure calculations. Adv. Chem. Phys. 69, 399–445 (1987).

    CAS  Google Scholar 

  44. 44.

    Frutos, L., Andruniow, T., Santoro, F., Ferre, N. & Olivucci, M. Tracking the excited-state time evolution of the visual pigment with multiconfigurational quantum chemistry. Proc. Natl Acad. Sci. USA 104, 7764 (2007).

    CAS  Article  Google Scholar 

  45. 45.

    Hehre, W. J., Ditchfield, R. & Pople, J. A. Self-consistent molecular orbital methods. XII. Further extensions of Gaussian-type basis sets for use in molecular orbital studies of organic molecules. J. Chem. Phys. 56, 2257–2261 (1972).

    CAS  Article  Google Scholar 

  46. 46.

    Ufimtsev, I. S. & Martínez, T. J. Quantum chemistry on graphical processing units. 1. Strategies for two-electron integral evaluation. J. Chem. Theory Comput. 4, 222–231 (2008).

    CAS  Article  Google Scholar 

  47. 47.

    Ufimtsev, I. S. & Martinez, T. J. Quantum chemistry on graphical processing units. 2. Direct self-consistent-field implementation. J. Chem. Theory Comput. 5, 1004–1015 (2009).

    CAS  Article  Google Scholar 

  48. 48.

    Ufimtsev, I. S. & Martinez, T. J. Quantum chemistry on graphical processing units. 3. Analytical energy gradients, geometry optimization, and first principles molecular dynamics. J. Chem. Theory Comput. 5, 2619–2628 (2009).

    CAS  Article  Google Scholar 

  49. 49.

    Perdew, J. P. Density-functional approximation for the correlation energy of the inhomogeneous electron gas. Phys. Rev. B 33, 8822–8824 (1986).

    CAS  Article  Google Scholar 

  50. 50.

    Shao, J. & Tu, D. The Jackknife and Bootstrap (Springer-Verlag, Berlin, 1995).

Download references

Acknowledgements

This work was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. The experimental part of this research was performed at the SLAC MeV UED facility, which is supported in part by the DOE BES SUF Division Accelerator & Detector R&D program, the Linac Coherent Light Source (LCLS) Facility, and SLAC under contract nos. DE-AC02-05-CH11231 and DE-AC02-76SF00515. M.G. is funded via a Lichtenberg Professorship of the Volkswagen Foundation. D.M.S. is grateful to the NSF for a graduate fellowship. J.P.F.N. acknowledges the support of the Wild Overseas Scholars Fund of the Department of Chemistry, University of York. K.W. and M.C. are supported by the US Department of Energy Office of Science, Basic Energy Sciences under award no. DE-SC0014170. P.M.W. is supported by the US Department of Energy, Office of Science, Basic Energy Sciences, under award no. DE-SC0017995. A.K. is supported by the Carnegie Trust for the Universities of Scotland (grant ref. CRG050414) and an RSE/Scottish Government Sabbatical Research Grant (ref. 58507).

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T.J.A.W., J.Y., J.P.F.N., M.C., R.C., J.P.C., M.G., K.H., R.K.L., X.S., T.V., S.P.W., K.W., Q.Z, X.J.W. and M.P.M. prepared and conducted the experiment at the SLAC ultrafast electron diffraction facility. D.M.S., R.M.P. and T.J.M. performed the ab-initio simulations. T.J.A.W. analysed the experimental data. T.J.A.W., D.M.S., J.Y., R.M.P., M.C., M.G., A.K., J.R., P.M.W., H.Y., X.W., M.P.M. and T.J.M. interpreted the results. T.J.A.W., D.M.S., R.M.P. and T.J.M. wrote the manuscript. All the authors discussed the science of the paper.

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Correspondence to T. J. A. Wolf or X. J. Wang or M. P. Minitti or T. J. Martínez.

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Supplementary information

41557_2019_252_MOESM2_ESM.mov

1,3,5-hexatriene formation through the open-ring conical intersection

41557_2019_252_MOESM3_ESM.mov

1,3-cyclohexadiene formation through the open-ring conical intersection

41557_2019_252_MOESM4_ESM.mov

1,3-cyclohexadiene formation through the closed-ring conical intersection

Supplementary Information

Supplementary Discussion, Supplementary Table, Supplementary Figures 1–18, Detailed description of the Supplementary Movies.

Supplementary Movie 1

1,3,5-hexatriene formation through the open-ring conical intersection

Supplementary Movie 2

1,3-cyclohexadiene formation through the open-ring conical intersection

Supplementary Movie 3

1,3-cyclohexadiene formation through the closed-ring conical intersection

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Wolf, T.J.A., Sanchez, D.M., Yang, J. et al. The photochemical ring-opening of 1,3-cyclohexadiene imaged by ultrafast electron diffraction. Nat. Chem. 11, 504–509 (2019). https://doi.org/10.1038/s41557-019-0252-7

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