Synthesis, characterisation and structural elucidation of novel 4-tert-butylbenzohydrazone and its Cu(II), Ni(II), Co(II) and Mn(II) complexes

ABSTRACT. 4-Tert-butylbenzohydrazone ligand was synthesised by reacting 4-tert-butylbenzohydrazide with dehydroacetic acid. Afterward, the Cu(II), Ni(II), Co(II), and Mn(II) complexes of 4-tert-butylbenzohydrazone were synthesised. All the synthesised compounds were characterised using elemental analysis, ESI-MS, IR, 1H-NMR and 13C-NMR spectroscopic methods. ESI-MS studies revealed ligand to metal stoichiometry of 1:1 for the Cu(II) complex, 2:1 for the Ni(II), Co(II), and Mn(II) complexes. IR studies showed that the ligand was coordinated to the metal ions through ONO donor atoms. The 1H NMR revealed that deprotonation did not occur in the ligand. Thus, the hydroxyl oxygen and the secondary amine nitrogen did not participate in the coordination. The proposed structures of the compounds conform with the analytical results. KEY WORDS: 4-Tert-butylbenzohydrazone, Metal complexes, Structure, Elucidation Bull. Chem. Soc. Ethiop. 2023, 37(6), 1411-1422. DOI: https://dx.doi.org/10.4314/bcse.v37i6.9