Related Experiment Video
Updated: Mar 30, 2026

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
Published on: May 29, 2018
X-ray induced dimerization of cinnamic acid: Time-resolved inelastic X-ray scattering study
Juho Inkinen1, Johannes Niskanen1, Tuomas Talka1
1Department of Physics, P.O. Box 64, FI-00014 University of Helsinki, Helsinki, Finland.
Researchers observed X-ray-induced dimerization of cinnamic acid (CA) for the first time. Nonresonant inelastic X-ray scattering (NRIXS) revealed homogeneous dimerization and subsequent crystal disintegration, differing from UV-light reactions.
Area of Science:
- Solid-state chemistry
- Materials science
- Photochemistry
Background:
- Solid-state topochemical reactions are crucial in materials science.
- Photodimerization of alpha-trans-cinnamic acid (CA) using UV light is a well-established reaction.
- Understanding reaction mechanisms under different stimuli is essential for controlling chemical transformations.
Purpose of the Study:
- To report the first observation of X-ray-induced dimerization of CA.
- To monitor the X-ray-induced dimerization and subsequent reactions in situ.
- To compare the mechanism of X-ray-induced dimerization with UV-light-induced dimerization.
Main Methods:
- Nonresonant inelastic X-ray scattering (NRIXS) spectroscopy was used for in situ monitoring.
- Time-resolved NRIXS was employed to capture spectral evolution.
- Spectrum simulations of CA and its dimer, alpha-truxillic acid (TA), were performed.
- NRIXS-based tomography was utilized for spatial analysis.
Main Results:
- X-ray irradiation induced dimerization of CA on a short timescale.
- A subsequent disintegration of the crystal was observed on a longer timescale.
- The X-ray-induced dimerization was found to proceed homogeneously.
- NRIXS tomography provided spatial insights into the reaction progress.
Conclusions:
- X-ray-induced dimerization of CA is a novel phenomenon.
- NRIXS is a powerful tool for studying time-resolved chemical reactions in solids.
- The homogeneous nature of X-ray-induced dimerization contrasts with heterogeneous UV-light-induced dimerization.
More Related Videos
08:44Measurements of Long-range Electronic Correlations During Femtosecond Diffraction Experiments Performed on Nanocrystals of Buckminsterfullerene
Published on: August 22, 2017
09:15Combining X-Ray Crystallography with Small Angle X-Ray Scattering to Model Unstructured Regions of Nsa1 from S. Cerevisiae
Published on: January 10, 2018
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
X-ray Crystallography
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
X-ray Diffraction of Biological Samples
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal...
Determination of Crystal Structures