CRYSTAL ENGINEERING OF THIOUREAGLUTARIC ACID COCRYSTAL. A COMPARATIVE STUDY WITH UREAGLUTARIC ACID COCRYSTAL.
A. Kwasnica, T. Zych, I. Turowska-Tyrk & V. Videnova-Adrabinska
Institute of Inorganic Chemistry and Metallurgy of Rare Elements, Wroc3aw University of Technology, 27 Smoluchowskiego St, 50-370 Wroc3aw, Poland, e-mail: kwasnica@ichn.ch.pwr.wroc.pl
The hydrogen-bond network in thioureaglutaric acid cocrystal will be presented and compared with the hydrogen-bond network in urea-glutaric acid cocrystal. The titled crystal is designed using an engineering strategy based on the Kitaygorodsky Aufbau Principle (KAP). A statistical study in Cambridge Structural Data Base (CSD) evidenced similarity of the hydrogen bonds abilities in both urea and thiourea molecules. The purpose of present study is to promote the thiourea (instead of urea) molecule as a cocrystalising agent.
The single steps of design will be discussed starting from the supramolecular synton formation (KAP0), through chain or tape constructions (KAP1) and further organisation into two- and three-dimensional networks (KAP2,3). Each design step has been computer aided using the Cerius2 package (Biosym/MSI).
The geometry and topology of the hydrogen-bonded multidimensional networks in urea/thiourea cocrystals are compared with respect to eventual packing forces modifications issuing from electron density redistribution around the oxygen/sulphur atom and therefore dissimilarities in the hydrogen-bond acceptor capabilities. The results of this study provide hints for further design of urea and thiourea cocrystals by changing their recognition properties and therefore, fine-tuning the cocrystal properties.
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