Biologically active 3d metal complexes with 2-Formyl- and 2-acetylpyridine, of 4-allyl-S- diallylisothiosemicarbazones: synthesis, structure, and properties [Articol]

Abstract

Eight coordination compounds of Ni(II), Co(III), and Fe(III) with 2-formy-lpyridine (HL1) and 2-acetylpyridine (HL2) 4,S-diallylisothiosemicarbazones were synthesi-zed: [Ni(HL1)2)](NO3)2 (1), [Ni(HL2)2)](NO3)2 (2), [Ni(HL1)2)](I)2 (3), [Co(L1)2)]I (4), [Co(L2)2)] I (5), [Fe(L1)2)]NO3 (6), [Fe(L1)2)]Br (7), [Fe(L2)2)]NO3 (8). The ligands were characterized by NMR and FTIR spectroscopy, and the metal complexes were studied using elemental analysis, FTIR spectroscopy, and molar conductivity in methanol. The molecular structures of compounds 1–3 were confirmed via single-crystal X-ray diffraction. The biological activity of complexes was evaluated, revealing notable antibacterial, antifungal, and antioxidant properties. In particular, compounds 1, 2, 4, and 6 demonstrated higher antiradical activity against ABTS•+ cation radicals than Trolox, a commonly used antioxidant standard. These findings highlight the potential of such metal complexes in the development of new bioactive agents.