Synthesis, structural characterization and biological activity of fluorinated Schiff-bases of the type [C6H4-1-(OH)-3-(CHNArF)]

• A series of fluorinated imines were synthesized in a facile manner in high yields.
• Good antibacterial activities were observed.
• The position of the fluorine substituents is determinant on the biological activity.
• Studies in the solid state reveal important non-covalent interactions.
• This weak interactions may be important for the biological activities.

A series of fluorinated imines of the type [C6H4-1-(OH)-3-(CHNArF)]; ArFC6H4-4-F (1), C6H3-2,3-F2 (2), C6H3-3,5-F2 (3), C6H2-2,4,6-F3 (4), C6H4-3-CF3 (5), C6H3-3,5-(CF3)2 (6), were synthesized and fully characterized including single crystal X-ray diffraction analyses of compounds [C6H4-1-(OH)-3-(CHNC6H4-4-F)] (1), [C6H4-1-(OH)-3-(CHNC6H3-3,5-F2)] (3), [C6H4-1-(OH)-3-(CHNC6H4-3-CF3)] (5). Further analyses of these results allowed the identification of the predominant non-covalent interactions and supramolecular arrangements in the solid state. Exploration of the anti-bacterial activity against both gram-positive and gram-negative bacteria showed those compounds including F or CF3 substituents at the meta positions i.e. [C6H4-1-(OH)-3-(CHNC6H3-3,5-F2)] (3), [C6H4-1-(OH)-3-(CHNC6H4-3-CF3)] (5), [C6H4-1-(OH)-3-(CHNC6H3-3,5-(CF3)2)] (6), to be the best when their activity is compared versus ampicillin.

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