A localized view on molecular dissociation via electron-ion partial covariance

• Published in: Communications chemistry Vol. 5; no. 1; pp. 42 - 10
• Main Authors: Allum, Felix, Music, Valerija, Inhester, Ludger, Boll, Rebecca, Erk, Benjamin, Schmidt, Philipp, Baumann, Thomas M, Brenner, Günter, Burt, Michael, Demekhin, Philipp V, Dörner, Simon, Ehresmann, Arno, Galler, Andreas, Grychtol, Patrik, Heathcote, David, Kargin, Denis, Larsson, Mats, Lee, Jason W L, Li, Zheng, Manschwetus, Bastian, Marder, Lutz, Mason, Robert, Meyer, Michael, Otto, Huda, Passow, Christopher, Pietschnig, Rudolf, Ramm, Daniel, Schubert, Kaja, Schwob, Lucas, Thomas, Richard D, Vallance, Claire, Vidanović, Igor, von Korff Schmising, Clemens, Wagner, René, Walter, Peter, Zhaunerchyk, Vitali, Rolles, Daniel, Bari, Sadia, Brouard, Mark, Ilchen, Markus
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 28.03.2022; Springer Nature; Nature Publishing Group UK; Nature Portfolio
• Subjects: angular-distribution; ATOMIC AND MOLECULAR PHYSICS; atomic iodine; Binding energy; Chemical Sciences; Chemistry; coincidence; Covariance; data-acquisition; Free electron lasers; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Iodine; ionization dynamics; Kemi; laser; Light sources; mass-spectrometry; Molecular structure; Photochemistry; Photodissociation; photoelectron-spectroscopy; Photoelectrons; photoionization; Signal processing; Spectrum analysis; ultraviolet
• ISSN: 2399-3669; 2399-3669
• DOI: 10.1038/s42004-022-00656-w

Inner-shell photoelectron spectroscopy provides an element-specific probe of molecular structure, as core-electron binding energies are sensitive to the chemical environment. Short-wavelength femtosecond light sources, such as Free-Electron Lasers (FELs), even enable time-resolved site-specific investigations of molecular photochemistry. Here, we study the ultraviolet photodissociation of the prototypical chiral molecule 1-iodo-2-methylbutane, probed by extreme-ultraviolet (XUV) pulses from the Free-electron LASer in Hamburg (FLASH) through the ultrafast evolution of the iodine 4d binding energy. Methodologically, we employ electron-ion partial covariance imaging as a technique to isolate otherwise elusive features in a two-dimensional photoelectron spectrum arising from different photofragmentation pathways. The experimental and theoretical results for the time-resolved electron spectra of the 4d and 4d atomic and molecular levels that are disentangled by this method provide a key step towards studying structural and chemical changes from a specific spectator site.