Metal Complexes of Heterocyclic Hydrazone Schiff-Bases: Preparation, Spectral Characterisation and Biological Study

New isatinic hydrazone Schiff-base ligands, namely furan-2-carboxylic acid (2-oxo-1,2-dihydro-indol(3)- ylidene)-hydrazide (L-1), thiophene-2-carboxylic acid (2oxo- 1,2-dihydro-indol-3-ylidene)-hydrazide (L-2) and 2-(pyridine-2-yl-hydrazono)-1,2-dihydro-indol-3-one) (L-3) are reported. The ligands were prepared by the condensation of furan-2-carboxylic acid hydrazide (L-1), thiophene2- carboxylic acid hydrazide (L-2), and 2-hydrazino pyridine (L-3) with isatine. Monomeric complexes were prepared from the reaction of the corresponding metaLchloride with the ligands. The ligands and their nine new complexes of the generaLformulae [M(Ln)(2)] Cl-2 [where M = Co(II), Zn(II) and Cd(II); n = L-1, L-2 and L-3] were characterised by spectroscopic methods (FTIR, UV-Vis, H-1, C-13 NMR), elementaLanalysis, metaLcontent, magnetic measurement and molar conductance. These studies revealed the formation of six coordinate complexes, in which the geometry about metaLatom is a distorted octahedral. Biological activity of the ligands and their metaLcomplexes against Gram-positive bacteriaLstrain Bacillus (G(+)) and Gramnegative bacteria Ecoli (G(-)) are evaluated. The effects of prepared compounds depend on the type of tested bacteria. It is clear that the ligands and their metaLcomplexes have a potential effect on the Gram-positive (G(+)) and Gramnegative (G(-)) strains of the tested bacteria.