Synthesis, characterization and biological activity of some platinum(II) complexes with Schiff bases derived from salicylaldehyde, 2-furaldehyde and phenylenediamine.

Four platinum(II) complexes of Schiff bases derived from salicylaldehyde and 2-furaldehyde with o- and p-phenylenediamine were reported and characterized based on their elemental analyses, IR and UV-vis spectroscopy and thermal analyses (TGA). The complexes were found to have the general formula [Pt(L)(H(2)O)(2)]Cl(2) x nH(2)O (where n=0 for complexes 1, 3, 4; n=1 for complex 2. The data obtained show that Schiff bases were interacted with Pt(II) ions in the neutral form as a bidentate ligand and the oxygens rather than the nitrogens are the most probable coordination sites. Square planar geometrical structure with two coordinated water molecules were proposed for all complexes The free ligands, and their metal complexes were screened for their antimicrobial activities against the following bacterial species: E. coli, B. subtilis, P. aereuguinosa, S. aureus; fungus A. niger, A. fluves; and the yeasts C. albican, S. cervisiea. The activity data show that the platinum(II) complexes are more potent antimicrobials than the parent Schiff base ligands against one or more microorganisms.

Vibrational and thermal studies of the complexes (NH4)[VO(O2)2(phen)].2H2O and (NH4)[V(O2)3(phen)].2H2O.

The infrared spectra of the oxodiperoxo and triperoxo complexes, (NH4)[VO(O2)2(phen)].2H2O and (NH4)[V(O2)3(phen)].2H2O have been recorded and the observed bands are assigned on the basis of Cs symmetry. Thermogravimetric (TG) and differential thermal analysis (DTA) measurements on these two complexes were also carried out. A detailed mechanism for the mode of thermal decomposition of the two complexes has been given and supported by infrared spectral measurements on the thermal decomposition products. The data obtained agree quite well with the expected structure and indicate that the final thermal decomposition product of these two complexes is V2O5.