The synthesis of a new ligand, N4 Tetra (Methel Azometine)-Di Phenylen hydrazide (TMADPH), was carried out by condensing 1,2-diacetylhydrazine with 1,4 -phenylendiamin to obtain the ligand TMADPH. After confirming the structure of the bond using FT–IR, UV–VIS, 1H–NMR and 13C–NMR, its metal complexes with Zr4+, Mn2+and Ni2+ were prepared and studied using FT–IR, UV–VIS spectroscopy, electrical conductivity and metal ratio analysis. The results indicated that all the metal complexes had a mononuclear structure. Furthermore, the biological activity against Pseudomonas aeruginosa and Staphylococcus aureus bacteria was studied, revealing that the prepared metal complexes exhibited greater biological activity than the macrocyclic ligand. © 2025 Elsevier B.V., All rights reserved.