Synthesis And Characterization Of Nitrogenous Heterocycle Schiff Bases Ligands And Their Complexes

Schiff bases compounds have attracted a lot of researchers for a long time, because of their application in catalyst, simulating enzyme, antibody, molecular indentification and so on. Owing to the functionality of C=N, the electron effect, in recent decades the synthesis, physical and chemical properties of schiff base and their metallic complexes were reported extensively. They can be served as chelated reagents, and biology-active reagents. On the other side, benzimidazole derivatives can control the growth of bacteria, many of them also have the properties of antivitamin B₁₂, antibacterial and antiviral. So the study of synthesis and properties of this nitrogenous heterocycle have become a quite active subject in heterocyclechemistry and coordinated chemistry fields.In our lab, cobalt complexes of schiff bases and of benzimidazoles synthesized by solid-state reaction can absorb oxygen,but there are some differences in their abilities to binding oxygen. In order to interpret the difference, this research has been started with ligands. Seven new schiff bases and three new benzimidazole derivatives have been synthesed. Six crystals have been obtained, tested, and discussed. Two of these shiff bases have been choosed to be as ligands, with which we have obtained two metal complexs with similar structures. The content of this work contains six parts:1. Recent development of schiff bases and nitrogenous heterocycle derivatives were reviewed, and prospect of application for they were also discussed.2. N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)-1,2-ethylenediamin(L₁), N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)-1,3-propanediamine(L₂), N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)-1,4-butanediamine(L₃), and N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)-1,4-phenylenediamine(L₄) were synthesized by 2-phenyl-1,2,3-triazole-4-carboxaldehyde, and these compounds were characterized by elemental analysis, IR, ¹HNMR and MS. Three of them were determined by x-ray diffraction.3. N,N'-bis((quinoxalin-2-yl)methylene)-1,2-ethylenediamin(L₅), N,N'-bis(( quinoxalin-2-yl)methylene)-1,3-propanediamine(L₆)and N,N'-bis((quinoxalin- 2-yl)methylene)-1,4-butanediamine(L₇) were synthesized by quinoxalin-2- carbo- xaldehyde, and these compounds were characterized by elemental analysis, IR, ¹HNMR, MS and UV spectrum.4. 2-(2-phenyl-2H-1,2,3-triazol-4-yl)-1H-benzoimidazole(L₈), 2-(2-phenyl-2H -1,2,3-triazol-4-yl)-1-((2-phenyl-2H-1,2,3-triazol-4-yl)methyl)-1H-benzoimidazole (L₉)and 2-(2-quinoxalin-2-yl)-1-((2-quinoxalin-2-yl) methyl) -1H-benzoimidazol (L₁₀) were synthesized directly by 2-phenyl-1,2,3-triazole-4-carboxaldehyde or quinoxalin-2-carboxaldehyde with o-phenylenediamine, and these three compounds were determined by elemental analysis, IR, 1HNMR, MS and x-ray diffraction. The fluorescent properties of compounds L9 and L10 were mensurated, and were found that they have good properties, so they have the possibility to be potential materials.5. N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)-1,2-ethylenediamin was deoxidized by NaBH4, and the corresponding compound(L₁₁) was characterized by elemental analysis, IR, 1HNMR and UV spectrum.6. Based on the fomer experiments, two similar complexes were synthesized by (L₁) and (L₂): [Ni·(L₁)](NO₃)₂ and [Cu·(L₂)](NO₃)₂. They were characterized by elemental analysis, IR, DTA-TG , XRD, molar conductance and cyclic voltammetry.