Homonuclear site-specific photochemistry by an ion–electron multi-coincidence spectroscopy technique

Abstract

PostprintThis is the accepted version of a paper published in Chemical Physics Letters. This paper has been peerreviewed but does not include the final publisher proof-corrections or journal pagination.Citation for the original published paper (version of record):Eland, J H., Linusson, P., Mucke, M., Feifel, R. (2012) Homonuclear site-specific photochemistry by an ion-electron multi-coincidence spectroscopy technique. Abstract By combining multi-particle coincidence detection of electrons and ions with ionization by soft X-ray synchrotron radiation we demonstrate an effective tool for atomic spectroscopy and sitespecific photochemistry. Its most novel capability is application to molecular fragmentation after K-shell vacancy production in atoms distinguished only by their chemical environment. Chemical Physics Letters

Single-photon double and triple ionization of acetaldehyde (ethanal) studied by multi-electron coincidence spectroscopy

“…We note, that a similar difference between the experimental Auger spectra presented in Fig. 4 has been observed before in the Auger spectra associated with formylic and methylic C1s in acetone, as presented in the work by Eland et al 32 . In comparing our experimental result with the known theoretical spectra, we note a reasonable agreement, bearing in mind the limited resolving power with the original experimental Auger data of Correia et al 40 .…”

Mechanisms of site-specific photochemistry following core-shell ionization of chemically inequivalent carbon atoms in acetaldehyde (ethanal)

“…17 carried out a study on ozone, and Nagaoka et al [18][19][20] investigated the dissociation of some trihalosilyltrimethylsilyl-compounds upon core ionisation of the silicon 1s and 2p inner shells. Site-specific photochemistry arising from initial ionisation at the allimportant carbon atoms of organic molecules was studied by Itälä et al 21 for the case of pyrimidine and by some of us 22 for the case of ethyl trifluoroacetate.…”

“…The amount of energy deposited (the magnitude of the energy transfer) can also affect the outcome as seen in acetone 22 .…”

“…If the breakdown pattern depends only on the ions' total internal energy content (as assumed in the statistical theory of mass spectra for a molecule of this size), then differences in mass spectra can be caused by differences in the energy deposition, that is by differences in the Auger spectra from vacancies on different atoms, defined by the overlap between the core hole and the valence orbital 6 . As known from the very recently investigated cases of acetone 22 , ethyl trifluoracetate 23 and acetaldehyde 24 , the Auger spectra from holes on different C atoms can be significantly different. At the other extreme, if Auger decays from different atoms produce exactly the same total energy distribution in the ions, then differences in ion behavior could still arise if the same amount of energy is deposited in different quantum states (including location) which decay in different ways.…”

Selectivity in fragmentation of N-methylacetamide after resonant K-shell excitation

“…Since then, many studies have been performed on this topic in the gasphase [25][26][27][28][29][30] as well as on surfaces 22,[31][32][33][34] and site-specific bond breaking has been observed in both cases. Also, sitespecific fragmentation initiated by core ionization has been reported [35][36][37][38][39][40][41][42][43] .…”