Synthesis, Characterization And Catalytic Activity Studies Of Phosphoester Model Complexes Containing Macrocyclic Polyamine

The study of phosphoester metallohydrolases has become one of the active fields of bio-inorganic chemistry in recent years. In this thesis, 28 new mononuclear and dinuclear complexes have been synthesized on the basis of going over and analyzing a great deal of references. Their structures and properties such as crystal structure, IR and UV-vis spectra and TG-DSC have been studied in detail. Furthermore, the studies on the hydrolysis of bis(2,4-dinitrophenyl) phosphate (BDNPP) and carboxy ester 4-nitrophenyl acetate (NA) promoted by the metal complexes have also been carried out. The main work includes:1. On the basis of previous literatures, the macrocyclic 1,4,7,10-tetraazacyclododecane (cyclen) and 5 mononuclear complexes include two single crystals have been efficiently synthesized and characterized by IR, UV-vis spectra and TG analysis. The results show that complexes 1⁴ have the similar structure, and the metal is six-coordinated by the four nitrogen atoms from cyclen and two oxygen atoms of acetate, While the Zn(â…¡) ion in complex 5 is five-coordination with the four pyramid conformation.2. Four dinuclear complexes containing cyclen bridged by succinic acid have been synthesized and characterized by elemental analysis, molar electrolytic conductivity, IR and UV-vis spectra. One of which has been determined by X-ray single diffraction. The results show that the four complexes have the same structure and are tetradentate-bridged by succinic acid. The crystal structure of complex 7 indicates that the eight atoms of succinate are in one plane (esd: 0.00743 nm), and this phenomenon is less observed in the complexes involving saturated fatty diacid.3. One mixed-valent manganese complex has been synthesized and characterized by IR spectrum and X-ray single diffraction. The UV-vis spectrum of the complex has two peaks at 553 and 644nm. The cyclic voltammogram shows that a quasi-reversible redox wave with E_1/2 is 0.827V, assigning the Mn (â…¢,â…£) to Mn (â…£,â…£) state. The Mn…Mn distance (2.691 A) is about the same as those distances found in oxygen evolving complex of PSII.4. Six types of supermolecular complexes containing cyclen have been synthesized and characterized by elemental analysis, IR and UV-vis spectra, and thermal analysis. Four of which have been determined by X-ray single diffraction. Complex 12 and 13 are the three-dimensional network and zigzag chain constructed through the hydrogen bonds formed by the oxygen atoms from the terephalic acid and the oxygen atoms of lattice water and coordination water, respectively. Complex 15 is the three-dimensional network constructed through the hydrogen bonds formed by the nitrogen atoms of cyclen and the oxygen atoms from fumarate acid andcoordination water. Complex 16 is the one-dimensional chain constructed through hydrogen bonds formed by the nitrogen atoms from cyclen and the oxygen atoms of glutarate acid and lattice water.5. Two novel bismacrocyclic ligands Li, L2 and four transitional metal complexes have been synthesized characterized by elemental analysis, IR and UV-vis spectra and 'HNMR, and the melt point and protoned constant of ligands L| and L2 were also determined. The curves of species distribution of ligand L| and L2 in different pH condition are also reported. The spectral properties of the dinuclear complexes show that the two ions are five-coordination, and each ion is coordinated by three nitrogen atoms from ligand L| and two oxygen atoms from two different bridged acetate, which bridge the two ions using syn-syn mode.6. The ramification DOTA and DOTP of macrocyclic cyclen and eight complexes have been synthesized and characterized by elemental analysis, IR and UV-vis spectra. Two of which have been determined by X-ray single diffraction. The results show that the metal ions are coordinated by the four nitrogen atoms from DOTA or DOTP and two oxygen atoms from the two contraposition carboxyl groups, forming the distorted octahedron conformation. Through the abundant hydrogen bonding in the molecules, one dimensional supermolecular structure has been formed.7. The mononuclear and dinuclear complexes, especially complexes 17, 18 and 19, can efficiently catalyze the hydrolysis of phosphodiester substrate BDNPP, which can be considered that the two ions play a cooperative role in catalytic reaction. Compared with some rare earth complexes, the catalytic activities are little poor. However, as the life-needed metal complexes, the catalytic activities are very important, and have the potentiality to be new nuclear cleavage reagents.