Science 28Feb2020

ACKNOWLEDGMENTS
We thank D. Heyes for help with laser flash photolysis
studies.Funding:D.L. thanks EPSRC for a Fellowship
(EP/P004997/1) and the European Research Council for
a research grant (758427).Author contributions:F.J.
and D.L. designed the project and wrote the manuscript.
T.C., M.Z., A.R., and F.J. performed all experiments.
N.S.S. performed the computational studies. All authors

analyzed the results.Competing interests:The authors

declare no competing interests.Data and materials

availability:All data are available in the main text or the

supplementary materials.

SUPPLEMENTARY MATERIALS

science.sciencemag.org/content/367/6481/1021/suppl/DC1

Materials and Methods

Figs. S1 to S24

Tables S1 to S16

NMR Spectra

References ( 45 – 101 )

16 November 2019; accepted 31 January 2020

10.1126/science.aba2419

Constantinet al.,Science 367 , 1021–1026 (2020) 28 February 2020 6of6

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