Researchers from the Department of Chemistry Nikola Bedeković, Nea Baus Topić, Vinko Nemec and Dominik Cinčić and students of the Department of Chemistry Sara Cerovski and Ruđer Sušanj have published an article titled Evaluation of halogen bonding proclivity of oxazole derivatives carrying multiple acceptor sites in cocrystals with perfluorinated iodobenzenes in the RSC journal CrystEngComm (IF 2.6). The paper was highlighted on the inside front cover of the issue.
The manuscript presents a systematic study of the competition between different acceptor sites for halogen bonding in the synthesized oxazole derivatives that are multifunctional N,O,X-acceptors (X = S, O, N or π aromatic ring). Cocrystallization with selected perfluorinated iodobenzenes has yielded 19 single crystals of cocrystals out of 28 possible combinations. Structural analysis revealed that the dominant intermolecular interaction in all obtained cocrystals is the I∙∙∙Noxazole halogen bond that is, according to relative shortening values, comparable to the well-studied and reliable I∙∙∙Npyridine halogen bond. Oxazole derivatives are ditopic acceptors in 10 cocrystals and form additional I∙∙∙N, I∙∙∙O or I∙∙∙π halogen bonds. The experimental results are in agreement with calculations of molecular electrostatic potential values on geometries that were optimized using density functional theory, since the most negative values corresponds to the oxazole nitrogen atom. Furthermore, the observed supramolecular architectures in the cocrystals were determined to be related to differences in molecular electrostatic potentials of the oxazole oxygen atom and the peripheral functionalities.
This research was performed as part of the project New building blocks for the supramolecular design of complex multi-component molecular crystals based on halogen bonds (HaloBond IP-2019-04-1868), financed by the Croatian Science Foundation.
Pristupačnost
