Study On Synthesis, Structure And Properties Of Metal Complexes With V-shaped Bis-schiff Base

In recent years, containing schiff base as one of the most common C = N ligands has been extensive research, this is mainly because of its coordination framework stable structure, easy to replace.At the same time a lot of schiff base compounds have certain antibacterial, anti-cancer, anti-oxidation, catalysis, good properties of fluorescent, etc.This thesis mainly designed and synthesized three v-shaped bis-schiff base ligands:Bis(3-methoxysalicylidene)-3-oxapentane-1,5-diamine H2L1Bis(5-methylsalicylaldehyde)-3-oxapentane-1,5-diamine H2L2Bis(N-salicylidene)-3-oxapentane-1,5-diamine H2L3With these ligands and metal ion salt reaction for seven metal complexes :[Sm(H2L1)(NO3)3](1),[Eu(H2L1)(NO3)3](2),[Dy(H2L1)(NO3)3](3),[Yb(H2L1)(NO3)3](4),[Mn2L22Ac2](5),[Zn2L22]∞(6),[Zn2L32]∞(7)。At the same time by elemental analysis, IR and UV-visible spectroscopy, nuclear magnetic resonance spectroscopy and other methods were used to characterize the complex. With X- ray diffraction have been their crystal structure. Results show that the complexes, 1-4 are mononuclear species(ten-coordinate), 5 are binuclear neutral entity(six-coordinate), 6(four-coordinate) and 7(five-coordinate) are 1-D ribbon framework. And there are larger cavity structure in the complexes 5, 6.In antioxidant activity experiments hydroxyl radicals(OH·) were generated in aqueous media through the Fenton-type reaction and the superoxide radicals(O2-·) were produced by the system MET/Vit B2/NBT. The results show that the data of IC50 are all at 10-5 M level for the ligand and all Ln(III) complexes, accordingly. We compared the abilities of one present compounds to scavenge radical with those of the classic natural antioxidants vitamin C and mannitol. The data of IC50 are all at 10-3 M level for mannitol and vitamin C. The results imply that the Ln(III) complexes have the preferable ability to scavenge hydroxyl radical(OH·) and superoxide radicals(O2-·) than mannitol and vitamin C.Fluorescence spectrum of the research results show that both ligands and complexes, in terms of photoluminescence have excellent properties.After study, can be in photographic materials, ion probe, such as fluorescent sensors for further exploration.