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Information × Registration Number 0221U106597, 0120U104907 , R & D reports Title Study of polymorphic transitions of molecular crystals for the needs of the pharmaceutical industry. popup.stage_title Head Shyshkina Svitlana V., Registration Date 15-12-2021 Organization State Scientific Institution Scientific and Technological Complex" Institute of Single Crystals "of the National Academy of Sciences of Ukraine popup.description2  Quantum chemical methods have been used to study the crystal structures of ibuprofen and mefenamic acid, whose molecules are similar to piracetam in their ability to form intermolecular interactions, but in whose crystals a polymorphic transition under pressure was not detected, unlike piracetam crystals. According to the calculations of the pairwise interaction energies between molecules, the polymorphic form I of ibuprofen has a layered structure, and the polymorphic form I of mefenamic acid has a columnar-layered structure of dimeric building units. Modeling of possible deformations of the crystal structure revealed criteria that indicate resistance to pressure. Such criteria are the absence of a local energy minimum in the region of the starting geometry on the energy profile of the shear of the layers and a high energy barrier of the shear of the layers. Depending on the value of the energy barrier, the crystals remain without significant changes (ibuprofen, up to 4 GPa) or disintegrate (mefenamic acid, 3 GPa). Product Description popup.authors popup.nrat_date 2021-12-15 Close