Study On Thermochemical Property And Bacteriostastic Activity Of Complex Of Rare Earth

Both rare earth ions and 8-hydroxyquionoline take on bacteriostastic and inflammation -diminishing activities, and amino acids are the structure units of proteins in human body, therefore, to study the thermochemical properties of mixed complexes of rare earth with 8-hydroxyquionoline or amino acids can fill a gap in their thermodynamical functions, and to explore their bacteriostastic activities is of positive significance to improve the study of high efficiency and low toxicity medication.The main contribution of this thesis includes:Firstly, rare earth trichloroacetic acid salts, the mixed complexes of rare earth trichloroacetic acid salts with 8-hydroxyquionoline and rare earth hydrochloric acid salts with glycine and alanine were synthesized and characterized by IR, elementary analysis, thermogravimatric analysis and chemical analysis. Secondly, basing on the thermochemical cycles of reactions designed, the dissolution enthalpies of different reactants and products systems were mensurated in three kinds of solutions by a improved, precision, automatic and isoperibol calorimeter, furthermore, the themochemical cycles of reactions proved with UV spectrums and refractive indexes. Thirdly, in terms of Hess Law, the reactions enthalpies of nine reactions, the standard enthalpies of formation of nine complexes and lattice energies of the mixed complexes of rare earth hydrochloric acid with glycine and alanine were evaluated. Finally, the bacteriostastic activities of two kinds of mixed complexes were experimented using the flat filter paper method, and bacteriostastic principles studied. Several conclusion achieved by study: the bacteriostastic activities of the mixed complexes of rare earth is better than that of single rare earth salts and their coordinate compounds; the bacteriostastic activities boost up with the increase of the concentration of complexes; their thermostability is better; their bacteriostastic effect lasts longer and the bacteriostastic activities of the mixed complexes of rare earth trichloroacetic acid salts with 8-hydroxyquionoline obviously exceed the mixed complexes of rare earth hydrochloric acid salts with glycine and alanine; as far as the bacteriostastic effect to monascus is concerned, under the conditions as follows: at 37℃,with pH value of 7.0 and the concentration of 0.002mol.L~-1, the diameter of bacteriostastic circle of the complex of rare earth trichloroacetic acid salts with 8-hydroxyquionoline is up to 20.0 mm, among which the complex of La-trichloroacetic acid salts with 8-hydroxyquionoline and the complex of Ce-trichloroacetic acid salts with 8-hydroxyquionoline perform the best.