Synthesis, Mimic Enzyme Catalysis, Supramolecular Metal-ion Recognition And Detection Of Macrocyclic Polyamine Compounds

The mimicry of hydrolytic metalloenzyme is now an active research area in chemistry and bionics. In this dissertation , new macrocyclic polyamine compounds have been designed and synthesized. Their supramolecular recognition for metal ion guest, and the mimic enzyme catalytic properties of their metal ion complexes have been studied. A series of useful information have been obtained, which provides certain theoretical basis for designing artificial hydrolytic metalloenzyme and enriches the study of metal ion supramolecular recognition. In order to probe the difference in hydrolysis of carboxylic ester catalyzed by complex of different stereomeric ligand, mutual stereomeric tetraaza macrocyclic polyamines ligands and their Cu(II) complexes have been synthesized. The kinetics and mechanism for the hydrolysis of p-nitrophenyl picolinate(PNPP) catalyzed by metal complex in the presence of Brij35 have been systematically studied. The effect of stereomeric ligands and micellar micro-environment on hydrolysis of PNPP have been discussed. The result reveals that the space structure of complex which is determined by stereomeric ligand, lead to the different hydrolytic activities of the complexes. Therefore, much attention should be paid to the steric configuration of ligand in designing artificial metalloenzyme. For the purpose of examining the effect of metal complex of ligand bearing hydroxyl group on catalytic hydrolysis of carboxylic ester, ligand of hydroxyethyl-functionalized tetraaza macrocyclic polyamine and its Cu(II) complex have been designed and synthesized. In the presence of Brij35 micellar solution, the kinetics and mechanism for the hydrolysis of PNPP catalyzed by the complexes have been studied. The effect of hydroxyl and micellar micro-environment on hydrolysis of PNPP have been discussed. From the results we can conclude that hydroxyethyl-founctionalized macrocyclic polyamine Cu(II) complex may catalyze PNPP hydrolysis effectively, and the catalytic process is of the typical characteristic of acid-base catalysis, which results from the deprotonation of the hydroxyl followed by an intramolecular nucleophilic attack in carboryl of substrate PNPP . To study the effect of geometry of complex on hydrolysis of carboxylic ester, using 2-aminopyridine as ligand, Zn(II),Ni(II) and Cu(II) complexes have been synthesized, and their properties which can catalyze the hydrolysis of PNPP and PNPA have been studied kinetically . Possible catalytic mechanism have been proposed. The results show that Zn(II) and Ni(II) complexes are catalyticly activie due to their similarity to the steric struture of in active center nature enzyme while Cu(II) complex has no catalytic activity because of the difference in geometry. Therefore, the geometry of metal ion coordination should be taken into account in constructing model of artificial hydrolytic metalloenzyme. In order to search the fluorescence chemical sensors for metal ions with high sensitivity and selectivity, a new suppramolecular compound of derivative macrocyclic polyamine has been designed and synthesized and its recognition characteristic for metal ions has been tentatively researched. The result shows that the above supramolecular system has high selectivity for trace copper and may be as a potential sensor for the detection of the trace copper ion in various samples.