Monitoring Structural Transformations in Crystals. Part 15. Structural Changes in Crystals Caused by UV Radiation Despite the Lack of a Photochemical Reaction

摘要

Crystals of 3-benzoylbicyclo[2.2.1]heptane-2-carboxylic acid (C15H16O3) do not undergo the photochemical reaction, namely the Yang photocyclization, but they undergo UV radiation damage. The initial stages of this process were monitored by X-ray diffraction and structure analysis. The results show that the process is smooth and accompanied by the decrease of the overall scale factor, the certain increase of width of reflections, the increase of the cell parameters, intermolecular distances, atomic displacement parameters and the small changes in orientation of molecular fragments.