Presence Of Nitrogen Donor Ligands Research Articles

Anti-inflammatory drugs interacting with Zn (II) metal ion based on thiocyanate and azide ligands: Synthesis, spectroscopic studies, DFT calculations and antibacterial assays

Zinc (II) complexes with non-steroidal anti-inflammatory drugs (NSAIDs) naproxen (nap) and ibuprofen (ibu) were synthesized in the presence of nitrogen donor ligands (thiocyanate or azide). The complexes were characterized by elemental analysis, FT-IR, 1H NMR and UV–Vis spectroscopes. The binding modes of the ligands in complexes were established by means of molecular modeling of the complexes, and calculation of their IR, NMR and absorption spectra at DFT (TDDFT)/B3LYP level were studied. The experimental and calculated data verified monodentate binding through the carboxylic oxygen atoms of anti-inflammatory drugs in the zinc complexes. The calculated 1H, FT-IR and UV–Vis data are in better agreement with the experimental results, and confirm the predicted tetrahedral structures for the Zn (II) complexes. In addition to DFT calculations of complexes, natural bond orbital (NBO) was performed at B3LYP/6-31+G(d,p) level of theory. Biological studies showed the antibacterial activity of zinc complexes against Gram-positive and Gram-negative bacterial strains.

Synthesis, structures and hydrolytic properties of metal complexes with 1,3-bis[(4-methyl-5-imidazol-1-yl)ethylideneamino]propan-2-ol

Synthesis of a polydentate ligand comprising imidazole donors, 1,3-bis[(4-methyl-5-imidazol-1-yl)ethylideneamino]propan-2-ol (BIPO), and its Zn II ( 1), Mn II ( 2), Ni II ( 3) and Cu II ( 4) complexes are reported. Single-crystal structural analysis shows that complex 1 adopts a distorted square-pyramidal coordination geometry with the basal positions occupied by the four nitrogen atoms of a tetradentate BIPO ligand and the apical position by a water molecule, complexes 2 and 3 exhibit elongated octahedral coordination geometries with the axial positions occupied by a pair of aqua molecules, whereas complex 4 exhibits an elongated octahedral geometry with the axial positions occupied by an aqua molecule and a perchlorate oxygen atom. The crystal structures of the four complexes are discussed in relation to the preference of zinc ion in carbonic anhydrase, and suggest that in the presence of nitrogen donor ligands, Zn II has a significant tendency to form a four- or five-coordination. Hydrolysis of 4-nitrophenyl acetate with complexes 1– 3 shows that the k obs for complexes 1, 2 and 3 were 2.74×10 −2± 0.01, 1.45×10 −2± 0.01 and 0.98×10 −2± 0.01 M −1s −1, respectively.

Effect of nitrogen‐donor ligands on the stability of the photolysis products of Mn2(CO)10

AbstractThe photolysis of Mn2(CO)10 in the presence of nitrogen donor ligands has been investigated in various solvents. The disproportionation reaction has been found to be strongly dependent on the solvent and on the temperature. The substitution of CO with the nitrogen donor ligand takes place on the anion Mn(CO)−5. The polymeric ligand poly(4‐vinylpyridine) manifests a stabilizing effect on the substitution product.