Crystal Structures, Synthesis Of Schiff Bases And Benzimidazole Derivatives, Study On Different Ability To Bind Oxygen Between Their Co(Ⅱ) Complexes

Owing to the function of C=N, Schiff bases and their metallic complexes havebeen widely investigated for one a century. In recent years, the synthesis, physical andchemical properties about them were reported extensively. These metallic complexesare known to be biologically important and serve as catalysts in various chemical andphotochemical reactions. On the other side, there is considerable interest in the use ofbenzimidazole complexes to model the active site of a variety of metalloenzymes suchas carbonic anhydrase and carboxypeptidase. Because of their parasitic and antiviralactivities, benzimidazole and some substituted benzimidazole compounds have beenwidely investigated in commercial medical fields. The study on oxygen carrier is of significance in military and civil applications,especially in the fields of dioxygen separation, metal anti-corrosion and keeping fruitsfresh. In our lab, cobalt complexes of Schiff bases and of benzimidazoles synthesizedby solid-state reaction can absorb oxygen. But there are some differences in theirabilities to binding oxygen. In order to interpret the machanics to absorb oxygen fromcrystal structure, crystals of ligands were obtained and tested. The content of thiswork contains five parts. 1. Recent development of oxygenated complexes was reviewed. Synthesis and prospect for Schiff bases and benzimidazole derivatives were discussed. 2. N,N'-bis(4-methoxybenzyl)ethylenediamine and N,N'-bis(3-methoxy-4 -hydroxylbenzyl)ethylenediamine were synthesized by p-methoxy- benzaldehyde or vanillin and ethylenediamine, and these compounds were characterized by elemental analysis, IR and x-ray diffraction. 3. 1-(p-methoxylbenzyl)-2-(p-methoxylphenyl)-benzimidazole, 1-(3-metho xyl-4-hydroxylbenzyl)-2-(3-methoxylbenzyl-4-hydroxyphenyl)- benzi- midazole, 1-(p-hydroxylbenzyl)-2-(p-hydroxylbenzylphenyl) –benzi- midazole and 1-(m-nitrobenzyl)-2-(m-nitrophenyl)-benzimidazole were synthesized directly by p-methoxybenzaldehyde, vanillin, p-hydroxyl- benzaldehyde or m-nitrobenzaldehyde and o-phenylenediamine, and these IIIcompounds were characterized by elemental analysis, IR and x-ray diffraction.4. The reactions of p-methoxybenzaldehyde with o-phenylenediamine and ethylenediamine yield two diffrent types of compounds N,N'-bis(3-methoxybenzyl)ethylenediamine and 1-(4-methoxybenzyl)-2- (4-methoxylphenyl)–benzimidazole. Zinc (II) complexes of these ligands were synthesized and characterized by x-ray diffraction, DTA-TG and cyclic voltammetry.5. Cobalt complexes of Schiff bases and cobalt complexes of benzimidazole were synthesized by solid-state reaction. Their oxygenation mechanics were proposed.