Photo-induced structural transformations in crystals at high pressure. Part 1. The crystallographic studies of the photochemical reaction at high pressure

The preliminary results of high-pressure X-ray diffraction studies of the intramolecular photochemical Norrish–Yang reaction in single crystals of the salt of 6,6-diethyl-5-oxo-5,6,7,8-tetrahydronaphthalene-2-carboxylic acid and (1S)-1-(4-methylphenyl)ethylamine are presented. The photo-induced changes in the cell parameters at high pressure along with the time of UV irradiation and the changes in the cell parameters along with pressure are discussed. The percentage change in the cell parameters brought about by the photochemical reaction at high pressure is similar to that at normal pressure. The cell volume decreases non-linearly with increasing pressure. The crystals lose their crystallinity above 2 GPa. This is the first paper in scientific literature on monitoring photochemical reactions in crystals at high pressure by X-ray diffraction.