X-ray induced dimerization of cinnamic acid: Time-resolved inelastic X-ray scattering study

Juho Mika Martti Inkinen, Heikki Toivo Johannes Niskanen, Tuomas Mikael Talka, Christoph Johannes Sahle, Harald Müller, Leonid Khriachtchev, Seyed Mohammad Javad Hashemi, Ali Akbari, Mikko Oskari Hakala, Simo Jooseppi Huotari

Research output: Contribution to journalArticleScientificpeer-review


A classic example of solid-state topochemical reactions is the ultraviolet-light induced photodimerization of α-trans-cinnamic acid (CA). Here, we report the first observation of an X-ray-induced dimerization of CA and monitor it in situ using nonresonant inelastic X-ray scattering spectroscopy (NRIXS). The time-evolution of the carbon core-electron excitation spectra shows the effects of two X-ray induced reactions: dimerization on a short time-scale and disintegration on a long time-scale. We used spectrum simulations of CA and its dimerization product, α-truxillic acid (TA), to gain insight into the dimerization effects. From the time-resolved spectra, we extracted component spectra and time-dependent weights corresponding to CA and TA. The results suggest that the X-ray induced dimerization proceeds homogeneously in contrast to the dimerization induced by ultraviolet light. We also utilized the ability of NRIXS for direct tomography with chemical-bond contrast to image the spatial progress of the reactions in the sample crystal. Our work paves the way for other time-resolved studies on chemical reactions using inelastic X-ray scattering.
Original languageEnglish
Article number15851
JournalScientific Reports
Publication statusPublished - 16 Nov 2015
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 114 Physical sciences

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