Structural, catalytic, antimicrobial and antioxidant properties of Cu(II)-complexes prepared by o-hydroxy Schiff bases with fluorine and ethoxy substituents

Cu(II) complexes of three Schiff bases were synthesized and characterized via X-ray diffraction, Fourier transform infrared, and UV-vis spectroscopies. The Schiff bases act as bidentate ligands, chelating Cu(II) ions in seesaw coordination geometry. Changing the substituent types and positions creates various non-covalent interactions within the crystal packings, yielding notable topological differences. GC-MS analysis reveals that Cu(II) complexes induce 1.38%-11.43% efficacy in Suzuki-Miyaura cross-coupling reactions. The biological activity of complexes correlates with substituent type and position in the aromatic ring. The one with ethoxy exhibits antimicrobial effects solely against Candida parapsilosis, while those with fluorine enhance the activity, particularly in the meta position.