Researches On Synthesis And Properties Of Thiophene Pantent Macrocyclic Binuclear Complexes

\This dissertation takes polynitrogen-complexes of phenol-based macrocycle as research objects, focusing on the study of synthesis, characterization, and nuclease activities of symmetrical and unsymmetrical dinuclear complexes with thiophene pendant, expecting to obtain novel complexes which have efficient nuclease activity and catalysis. Three new complexes below(the structures of relative ligands are given in Fig.1): [Cu₂L¹(Cl)₂]CH₃CN·H₂O 1; [Cu₂L²(OAc)]CH₃CN·H₂O 2; [Ni₂L³(OAc)](ClO₄)·2(CH₃CN) 3, were prepared and characterized by element analyses, IR, 1H-NMR, and X?ray diffractions techniques. Then, interactions with CT-DNA, activities and mechanism of cleaving supercoiled DNA (pBR322) were also systematically investigated via circular dichroism (CD) spectra, UV-vis absorption, fluorescent spectroscopy, viscosity experiment and cyclic voltammetry (CV) experiment. Finally, antibacteria experiaments for the complexes were also made.Main details as follows:1. The precursor compound N,N′-bis(2-thiophene)-N,N′-bis(3-formyl-5-methyl-salicylaldehyde)ethylenediamine(H₂L) was obtained respectively through two different synthesis routes. One was to synthesize precursor compound H₂L with one-pot reaction, mannich reaction among paraformaldehyde, 5-methyl-salicyladehyde, and N,N′-bis(2-thiophene)-1,2-diaminoethane. The other one had two steps. First, synthesize a sort of salicyladehyde derivative, namely 3-bromomethyl-5-methyl-salicyladehyde. Then, to make the derivative react with N,N′-bis(2-thiophene)ethylenediamine to abtain the H₂L. A couple of new unsymmetrical homodinuclear complexes of N(amine)2N(imine)₂O₂-type macrocycles were synthesized by template method via the reaction of H₂L with metal ions, ethylenediamine or 1,3-diaminopropane.2. Complex 3, a kind of Robson-Type dinickel macrocyclic complex was synthesized by a condensate reaction between N,N′-bis(3-aminopropyl)-2-thiophenediamine and 2,6-diformyl-4-chlorophenol.3. Binding mode of complexes 1 and 2, respectively, with CT-DNA were investigated systematically via CD spectra, UV-vis absorption, fluorescent spectroscopy, viscosity experiment and CV experiment, etc. Cleavage activities of the three complexes to pBR322 DNA have been monitored by agarose gel electrophoresis. What's more, mechanisms of cleaving pBR322 of the three complexes were also studied by addition of scavengers and anaerobic experiments.4. Antibacterial activities of complexes 2 and 3 against E. coli was evaluated by the paper disc diffusion method. Results show that both of the two complexes have appropriate antibacterial activities to E. coli, but 3 is of low antibacterial activity. Besides, 3 is a homodinuclear complex containing Ni ions. As a result, it has a pontential value of simulating the nickel-containing urease.