Synthesis, Structures And Biological Activity Of Transition Metal Complexes With Schiff Bases

Schiff base complexes have various structures and peculiar properties, so the use foreground of these complexes is promising in many fields, such as bioactivity catalysis and material, owing to their easy preparation, well coordinate capability to the transition metal ions. Studying the synthesis, structures and interactions between the metal ions and the Schiff base complexes is very important for the investigation of biological activity of the compounds.Urea is formed as a product of catabolism of human and animal nitrogen-containing complexes, which is stable in aqueous solutions. The urease can hydrolyze urea to give ammonia, which greatly reduce nitrogen utilization for animals and plants. Yet the enzymatic hydrolysis of urea causes an abrupt pH increase, which influence human and environment. So control the activity of urease through the use of inhibitors could counteract these negative effects, which is a effective method. Schiff base complexes maybe affect urease activity center, due to these structure characteristics. They will become potential urease inhibitors.1 Eight Schiff base ligands derived from the salicylaldehyde derivatives and 2-hydroxy acetophenone with primary amines have been synthesized. Seven mononuclear CuII, CoIII, NiII, MnII compounds have been synthesized through ligands coordinated with transition metal ions.2 Bis-Schiff base ligands have been synthesized through 3-oxethylsalicylaldehyde reaction with 1, 2-diaminoethane and 2-hydroxyacetophenone reaction with diethylenetriamine. Three mononuclear CuII, CoIII, MnII compounds have been synthesized based on ligands coordinated with transition metal ions.3 Four dinuclear and one polynuclear complexes have been synthesized through the Schiff base ligands coordinated with Cu, Zn ions, which derived from the condensation 2-hydroxyacetophenone and three amines. Two tetranuclear and one polynuclear complexes have been synthesized through the Schiff base ligands coordinated with Cu, Mn, Ni ions, which derived from the condensation salicylaldehyde derivatives and 2-Aminoethanol. One of them has been synthesized under solvolthermal conditions.4 The urease inhibitory activities of several complexes have been tested. As a result few tested complexes have urease inhibitory activity. Among the complexes, the Schiff base copper complexes have stronger urease inhibitory activities than other transition metal complexes.