Manganese (II) complex of bis(2- hydroxynaphthalene-1-carbaldehyde) oxaloyldihydra- zone has been synthesized. In view of the data obtained from the elemental analysis (CHNM), spectral (IR, 1H- NMR, mass, UV-Vis.), magnetism and thermal measurements, the structure of ligand / complex has been speculated. The ligand coordinated to the manganese ion in bi-dentate manner forming mononuclear tetrahedral complex. The free oxaloyldihydrazone and its manganese (II) complex were evaluated for their antimicrobial activities against gram- positive and gram-negative bacteria as well as fungi. The obtained results uncovered the ability of the free ligand to inhibit the growth of chosen bacteria. Whereas, the proliferation hindrance towards bacteria was slightly enhanced upon coordination with the manganese (II) ions. With respect to antifungals activity, the investigated compounds revealed insensitivity.

Keywords : Oxaloyldiydrazone Complex; Structural Studies; Pharmacological Application.