PREPARATION, CHARACTERIZATION AND THEORETICAL STUDY OF SOME METAL COMPLEXES OF NEW N[4-BIS(5-THION-1,3,4- OXADIAZOLE-2YL) METHANE) METHYL] DIBENZYL AMINE OF POSSIBLE BIOLOGICAL ACTIVITY

Abstract

A new Mannich base N[4-bis(5-thion-1,3,4-oxadiazole-2yl)methane)methyl] dibenzyl amine (L), have been prepared and characterized by (FTIR) spectroscopy. (L) has been used as a chelating ligand to prepare a number of metal complexes were isolated and characterized by (FTIR) (UV-Vis) spectroscopy, and Flame atomic absorption technique,in addition to magnetic susceptibility, and conductivity measurement. The study of the nature of the complexes formed in ethanolic solution following the mole ratio method, gave results which were compared successfully with those obtained from isolated solid state studies .The antibacterial activity for the ligand and their metal complexes were studied against two selected micro- organisms, pseudomonas aeruginosa and Bacillus subtilis, the antibiotics Ampicillin has been chosen to compare their activity with those of the new compounds. Theoretical treatment of the formation of the complexes in the gas phase, this was done using the HyperChem-6 program for the semi-empirical and molecular mechanics calculations. The heat of formation (ΔHfo) and binding energy (ΔEb) at 298K for the free ligand and their complexes were calculated by PM3 and AMBER. Furthermore the electrostatic potential of the free ligand was calculated to investigate the reactive sites of the molecule.PM3 was used to evaluate the vibrational spectra of the base(L) and compare the theoretically calculated wave number with the experimental values by using bis (5-thion-1,3,4-oxadiazole-2yl) methane, as authonetic compound. The theoretically obtained frequencies a gree with those values experimentally found, in addition, the calculation helped to assign unambiguously the most diagnostic bands.