New Copper and Cobalt Complexes Based on a Fluorinated Pyrazole Derivative, Synthesis, Characterization and Antibacterial Activity

Two copper and cobalt complexes based on 3-(trifluoromethyl)-4-((3-(trifluoromethyl)phenyl)diazenyl)-1H-pyrazol-5-ol (Httdp) have been prepared and characterized using different physicochemical techniques. The crystal structure of the copper complex has been proven to be a square pyramidal, and the cobalt complex has an octahedral structure. DFT calculations of the complexes were performed, and the energy gaps between the HOMO–LUMO of the complexes (−3.38676 to −3.18138 eV) and the Cu (II) complex reflect a higher relative stability compared with Httdp and the Co (II) complex. The antibacterial activities of the two complexes were evaluated. The Co (II) complex demonstrated the highest antibacterial activity against various bacteria compared with Httdp and the Cu (II) complex. The mean inhibition zones exhibited by the Co (II) complex showed the highest activities toward the Gram-negative bacterial strains with mean inhibition zones of 30.3 ± 0.6 (Staphylococcus aureus) and 25.7 ± 0.6 (Bacillus subtilis) mm. Docking studies were carried out using S. aureus tyrosyl-tRNA synthetase (PDB ID: 1JIJ) to assess the antimicrobial activities, proving that the complexes were efficient for the protein.