Wang, K. Murahari, P. Yokoyama, K. Lord, J. S. Pratt, F. L. He, J. Schulz, Leander Willis, M. Anthony, J. E. Morley, N. A. Nuccio, Laura Misquitta, A. Dunstan, D. J. Shimomura, K. Watanabe, I. Zhang, S. Heathcote, P. Drew, Alan J. 2016-12-12 Photochemical reactions are essential to a large number of important industrial and biological processes. A method for monitoring photochemical reaction kinetics and the dynamics of molecular excitations with spatial resolution within the active molecule would allow a rigorous exploration of the pathway and mechanism of photophysical and photochemical processes. Here we demonstrate that laser-excited muon pump–probe spin spectroscopy (photo-μSR) can temporally and spatially map these processes with a spatial resolution at the single-carbon level in a molecule with a pentacene backbone. The observed time-dependent light-induced changes of an avoided level crossing resonance demonstrate that the photochemical reactivity of a specific carbon atom is modified as a result of the presence of the excited state wavefunction. This demonstrates the sensitivity and potential of this technique in probing molecular excitations and photochemistry. application/pdf https://folia.unifr.ch/global/documents/305594 https://folia.unifr.ch/documents/305594/files/nuc_tmp.pdf https://folia.unifr.ch/documents/305594/files/nuc_tmp_sm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1038/nmat4816 info:eu-repo/semantics/openAccess License undefined Nature Materials. - 2017, vol. 16, no. 4, p. 467–473 info:eu-repo/classification/udc/53 Temporal mapping of photochemical reactions and molecular excited states with carbon specificity http://purl.org/coar/resource_type/c_6501