Hossein Nazari

Synthesis, crystal structures and antibacterial studies of oxidovanadium(IV) complexes of salen-type Schiff base ligands derived from meso-1,2-diphenyl-1,2-ethylenediamine

A series of new derivatives and previously reported Schiff base ligands and their oxidovanadium(IV) complexes were synthesized, characterized and tested as potential antibacterial agents against four human pathogenic bacteria. These N2O2 type Schiff base ligands were derived from the condensation of meso-1,2-diphenyl-1,2-ethylenediamine with different salicylaldehyde derivatives, and their metal complexes were obtained from the reaction of these ligands with bis(acetylacetonato)oxidovanadium(IV). Our studies showed that the metal complexes had moderate antibacterial activity, and this activity was higher than that of the free ligands against both Gram-positive and Gram-negative bacteria. Besides, it was found that the presence of more substituents on the ligands increases the antibacterial activities of both the free ligands and their complexes. The crystal structures of H2L4 and its corresponding complex VOL4 were determined by X-ray crystallography.

Synthesis, Characterization, and Biological Studies of New Ruthenium Polypyridyl Complexes Containing Noninnocent Ligands

Two new polypyridyl complexes [Ru(ttp)(L1)Cl]PF6 (1) and [Ru(ttp)(L2)Cl]PF6 (2) with noninnocent o-benzoquinonediimine (L1; bqdi) and 4,5-dimethyle-o-benzoquinonediimine (L2; 4,5-di-Mebqdi) ligands were synthesized and characterized (ttp = -p-toloyle-2,: ,-terpyridine). Cyclic voltammetry studies suggest that noninnocent ligands are coordinated in their benzoquinonediimine form. Preliminary ruthenium complexes-induced DNA dysfunction was studied on E. coli GM109 DNA by means of melting temperature analysis (Tm). Our results suggest that complex (2) inhibited DNA function more strongly compared to (1). Antibacterial activities of the complexes against E. coli bacteria were studied, and Minimum inhibitory concentration (MIC) values were evaluated. Both complexes showed great antibacterial activities.