Synthesis of complexes of copper(II), nickel(II), cobalt(II), manganese(II) and iron(III) with bidentate Schiff bases

The complexes of Cu I I , Ni I I , Co I I , Mn I I and Fe I I I with some Schiff bases derived from 3-acetyl-6-methyl-2H-pyran-2,4(3H)-dione (dehydrocetic acid; DHA) with p-toluidine, p-bromoaniline and p-anisidine have beensynthesized. The stoichiometry of the complexes has been found to be 1 : 1 and 1 : 2. The Cu I I , Ni I I , Co I I , Fe I I I complexes are monomeric with high-spin octahedral geometry, while the Mn I I complexes are dimeric in nature. Various ligand field parameters have been calculated. The fungluidal activities of the complexes have been screened.