A series of Schiff base ligands obtained by the condensation of trans-cyclohexane-1,2-diamine and fluorinated benzaldehydes were prepared, followed by their reduction with NaBH4. The reduced ligands were employed in the synthesis of zinc complexes of the general formula [ZnCl2(L)]. The structures of both the original and the reduced Schiff bases, as well as of the zinc complexes, were characterized by single-crystal X-ray analysis, along with NMR and IR spectroscopy. The antimicrobial activities of the reduced Schiff bases and their zinc complexes were evaluated in vitro against E. coli, S. aureus, and C. albicans. The compounds containing the 4-(trifluoromethylphenyl) moiety showed marked antibacterial activity. Interestingly, the antimicrobial effect of the zinc complex with this moiety was significantly higher than that of the corresponding free reduced ligand, comparable with ciprofloxacin used as standard. Thus, a synergic effect upon the complexation with zinc can be inferred.

Department of Cellular and Molecular Biology of Drugs Faculty of Pharmacy Comenius University in Bratislava Odbojárov 10 832 32 Bratislava Slovakia

Department of Chemical Theory of Drugs Faculty of Pharmacy Comenius University in Bratislava Odbojárov 10 832 32 Bratislava Slovakia

Department of Materials Chemistry Institute of Inorganic Chemistry of the CAS Husinec Řež č p 1001 250 68 Řež Czech Republic

Department of Physical Chemistry Faculty of Chemical and Food Technology Slovak University of Technology Radlinského 9 812 37 Bratislava Slovakia

NMR Laboratory Faculty of Pharmacy Comenius University in Bratislava Odbojárov 10 832 32 Bratislava Slovakia

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