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Information × Registration Number 0221U101182, 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 16-01-2021 Organization State Scientific Institution Scientific and Technological Complex" Institute of Single Crystals "of the National Academy of Sciences of Ukraine popup.description2  The object of the study - polymorphic transformations during grinding or under pressure in molecular crystals; polymorphic transition in piracetam. The purpose of the first stage is to study and systematize the literature data on studies of the effect of pressure on molecular crystals of different types. To investigate objects that affect the central nervous system and for which crystal structures have been determined before and after the polymorphic transition under pressure. Research methods - the database is created using open sources; theoretical studies of the structure of molecular crystals and modeling of the deformation process under the pressure influence were carried out by classical methods of quantum chemistry and using the periodic boundary. A database created contains data on 3258 objects studied under pressure or grinding. Objects registered as drug compounds (1284) were selected for which quantum chemical calculations were performed to determine the type of crystal structure. The structures are divided into three groups: 1) molecular crystals, for which there are data on the polymorphic transition under the pressure influence; 2) molecular crystals, for which there are data on the polymorphic transition due to grinding; 3) molecular crystals for which a polymorphic transition according to experimental studies was not detected. A study of piracetam showed that all six structures studied under pressure have a layered structure. The polymorphic transition is possible only due to the shift in the crystallographic direction a in the ab plane and leads to a significant weakening of the hydrogen bonds and strengthening of the dispersion interactions. The shift energy barrier is quite low, and the highest energy of interaction between molecules dimer and layer fragment in the model system is negative. The conducted researches are a new complex approach to studying of polymorphic transitions and have no analogues. Product Description popup.authors popup.nrat_date 2021-01-16 Close