Spectroscopic and mycological studies of Co(II), Ni(II) and Cu(II) complexes with 4-aminoantipyrine derivative

Complexes of the type [M(L)X2], where M = Co(II), Ni(II) and Cu(II), have been synthesized with novel NO-donor Schiff's base ligand, 1,4-diformylpiperazine bis(4-imino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one) which is obtained by the acid catalyzed condensation of 1,4-diformylpiperazine with 4-aminoantipyrine. The elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV, NMR, mass and EPR studies of the compounds led to the conclusion that the ligand acts as tetradentate chelate. The Schiff's base ligand forms hexacoordinated complexes having octahedral geometry for Ni(II) and tetragonal geometry for Co(II) and Cu(II) complexes. The mycological studies of the compounds were examined against the several opportunistic pathogens, i.e., Alternaria brassicae, Aspergillus niger and Fusarium oxysporum. The Cu(II) complexes were found to have most fungicidal behavior.

Graphical abstractCo(II), Ni(II) and Cu(II) complexes derived from novel Schiff's base ligand have been synthesized and characterized. The mycological studies of the compounds were examined against the opportunistic pathogens, i.e., A. brassicae, A. niger and F. oxysporum and the antipathogenic efficacy is expressed in concentration terms.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis of Novel Schiff base ligand 1,4-diformylpiperazine bis(4-imino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one). ► Complexes of Co(II), Ni(II) and Cu(II) with [M(L)X2] composition. ► Structural elucidation by the Physicochemical and spectral studies. ► Mycological investigations against the opportunistic pathogens.