Research On The Unsymmetrical Dinuclear Complexes Of Phenol-based N(amine)₂N(imine)₂O₂-type Macrocycles

This dissertation uses the polynitrogen-complexes of phenol-based compartmental macrocycles as research objects, focusing on the study of the synthesis, characterizations, properties and nuclease activities of the unsymmetrical dinuclear complexes of N(amine)₂N(imine)₂O₂-type macrocycles with two pendant furan groups, targeting the sythesis of novel complexes having efficient nuclease activity and catalysis. Nine new complexes (the structures of relative ligands are given in Fig. 1) [Cu₂(L¹)(OAc)](ClO₄)·3CH₃CN·H₂O 1, [Cu₂(L²)Cl₂]·CH₃CN 2, [Cu₂(L³)Cl₂]·CH₃CN·H₂O 3, [Mn₂(L³)Cl₂]·CH₃CN 4, [Ni₂(L³)Cl₂]·CH₃CN·H₂O 5, [CuZn(L²)Cl₂]·CH₃CN 6, [CuNi(L³)Br₂]·CH₃CN·H₂O 7, [CuZn(L³)(OAc)](ClO₄)·3CH₃CN·H₂O 8, [CuZn(L³)Cl₂]·CH₃CN·H₂O 9 and [Cu₂(L¹)(OAc)]Cl·4H₂O 10 with water cluster have been prepared and characterized by element analyses, IR, ¹HNMR, ES-MS, EDS and X-ray diffractions techniques, the electro-chemistry characterization and magnetism interactions between metal ions have been studied by recording the cyclic voltammograms and variable-temperature magnetic susceptibility data of the complexes, and the inhibitory bacteria activities of some complexes have been studied. The cleavage of DNA with complex 2 and three Cu(â…¡)Zn(â…¡) heterodinuclear complexes have been studied. The DNA-binding and the hydrolysis of 4-nitrophenyl phosphate catalyzed by complex 8 have been also investigated.The work is composed of:1. The precursor compound N, N'-bis(2-furyl)-N,N'-bis (3-formyl-5-bromosalicylaldehyde)ethylenediamine (H₂L) was prepared through the Mannich reaction between 5-bromosalicyladehyde and N, N'-bis(2-furyl)-1, 2-diaminoethane. Five new unsymmetrical homodinuclear complexes of N(amine)₂N(imine)₂O₂-type macrocycles were synthesized by stepwise template method through the reaction of H₂L with ethylenediamine, 1,3-diaminopropane and 1,3-diamino-2-hydroxypropane. The results show that: All metal ions have five coordinated atoms with distorted square-pyramidal configuration. The crystal packings of complexes are different because of their different axial donor atoms and macrocyclic ligands. Complexes 1, 2 and 3 have two redox processes, and their reduction potentials are affected by the size of macrocyclic ligands. The study of susceptibility shows that the complex 3 displays a strong antiferromagnetic exchange interactions between the two copper (â…¡) in the complex. Three dinuclear copper complexes have antibiotic activities for Escherichia coli.2. Four new unsymmetrical heterodinuclear complexes of N(amine)₂N(imine)₂O₂-type macrocycles were synthesized by stepwise template method. The results show that: The crystal structures of complexes 6,7 and 9 are similar with the homodinuclear complexes of the same macrocyclic ligands. Although the axial donor of complex 8 is same as the complex 1, the packings are different between two complexes because of the different macrocyclic ligand. Three Cu(â…¡)Zn(â…¡) heterodinuclear complexes 6,8 and 9 have one redox process, and their reduction potentials are affected by the size of macrocyclic ligands. Complex 7 have three redox process, which indicate that the copper complex of the same ligand exist in the complex 7 according to EDS. Antibiotic activity for Escherichia coli is no obvious difference between heterodinuclear and homodinuclear complexes, which indicate that the antibiotic activity is effected by the macrocyclic ligands.3. The cleavage reactions of supercoiled pBR322 DNA with three Cu(â…¡)Zn(â…¡) heterocomplexes were first monitored by agarose gel electrophoresis and the cleavage ability of complex 2 was also studied. The results show that: complex 2 was disable to cleave the supercoiled DNA; Complexes 6 and 9 exhibited the efficient cleavage of DNA, and the cleavage activity was enhanced by the increasing concentration of complexes. The complex 8 showed a very remarkable cleaving ability at 100μM and pH 8.0 without any external reagents. The oxidative mechanism of DNA cleavage was studied by adding standard radical scavengers. The interaction with CT-DNA of complex 8 was investigated by UV absorption and fluorescent spectroscopy. Results revealed the complex can bind to CT-DNA with an intercalative mode.4. Hydrolysis of 4-nitrophenyl phosphate catalyzed by the complex 8 was investigated by UV absorption spectroscopy. Results show that the complex approximately provides 6 orders of magnitude rate acceleration for the hydrolysis reaction and exhibits efficient catalysis. The hydrolytic kinetics and mechanism of phosphate monoester was studied as a function of pH, as well as concentration of the complex and substrate.5. Dicopper complex 10 of N(amine)₂N(imine)₂O₂-type macrocycle with (H₂O)₂₁ cluster was first synthesized. The study of crystal structure show that the 3-D supramolecular structure with infinite water channels was formed by hydrogen-bonding between water cluster chain and the host.