Synthesis, structural and fungicidal studies of hydrazone based coordination compounds

The coordination compounds of the Co(II), Ni(II) and Cu(II) metal ions derived from imine based ligand, benzil bis(carbohydarzone) were structurally and pharmaceutically studied. The compounds have the general stoichiometry [M(L)]X2 and [Co(L)X2], where M = Ni(II) and Cu(II), and X=NO3- and Cl− ions. The analytical techniques like elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV/Visible, NMR, ESI mass and EPR were used to study the compounds. The key IR bands, i.e., amide I, amide II and amide III stretching vibrations accounts for the tetradentate metal binding nature of the ligand. The electronic and EPR spectral results suggest the square planar Ni(II) and Cu(II) complexes (giso = 2.11–2.22) and tetragonal geometry Co(II) complexes (giso = 2.10–2.17). To explore the compounds in the biological field, they were examined against the opportunistic pathogens, i.e., Alternaria brassicae, Aspergillus niger and Fusarium oxysporum. The partial covalent character of metal-ligand bond is supported by the orbital reduction factor k (0.62–0.92) and nephalauxetic parameter β (0.55–0.57).

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis of hydrazone based imine. ► Complexes of Co(II), Ni(II) and Cu(II) with [M(L)X2] and [M(L)]X2 compositions. ► Structural elucidation by the Physicochemical and spectral studies. ► Fungicidal screening. ► Activation of the pharmaceutical action of the antipathogen by the metal ions.