Synthesis, Structure, and Biological Assays of Novel Trifluoromethyldiazepine–Metal Complexes

ROCHA, MARIANA; ECHEVERRÍA, GUSTAVO A.; PIRO, OSCAR E.; JIOS, JORGE J.; MOLINA, ROCÍO D. I.; ARENA, MARIO E.; ULIC, SONIA E.; GIL, DIEGO M.

AUSTRALIAN JOURNAL OF CHEMISTRY

CSIRO PUBLISHING

Año: 2020 vol. 73 p. 49 - 60

0004-9425

new series of CuII, NiII, CoII, and MnIII complexes have been synthesised from the (6Z)-6-(7-trifluoromethyl-1,2,3,4-tetrahydro-5H-1,4-diazepin-5-ylidene)cyclohexa-2,4-dien-1-one (HDZP) ligand. These complexes were characterised byelemental, spectroscopic (IR and UV-vis), and thermal analysis. The crystal structure of Cu-DZP was solved by X-raydiffraction methods. The complex crystallises in the monoclinic P21/c space group, with two molecules per unit cell. Thecrystal lattice is stabilised by different intra and intermolecular interactions. Hirshfeld surface analysis was employed toobtain additional information about interactions that are responsible for the crystal packing. Quantitative examination ofthe fingerprint plots indicated the dominant contribution ofH?HandH?X(X¼O, F) interactions in the crystal packing.In addition, C?H?chelate ring (CR) and C?H?p interactions are described in detail and evaluated using DFTcalculations. The antibacterial properties and the mechanism of inhibition of the main bacterial resistant mechanism,the biofilm, of the metal complexes and free ligand were investigated. [Mn(DZP)3]2H2O was the most active complexagainst the Pseudomonas aeruginosa biofilm formation with an inhibition of 40 %. However, none of the complexesinhibit more than 25% of the Gram negative bacteria microbial development. The most meaningful result was thebactericidal effect of [Co(DZP)2(H2O)2]2H2O against the Gram positive bacteria, Staphylococcus aureus, which inhibitsthe bacterial development and significantly reduces the biofilm formation at low concentration.