| 3-Aldehydosalicylic acid was firstly prepared by boiling hexamethylenetatramin and salicylic acid in aqueous slotion, and then the ligand, 3-aldehydosalicylic acid-2,4- dinitrophenyl hydrazone, was synthesized by 3-aldehydosalicylic acid and 2,4-dinitrophenyl hydrazine in ethanol solution.The novel thirteen complexes were synthesized by reacting 3-aldehydosalicylic acid-2,4- dinitrophenyl hydrazone and rare earth nitrate(RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Y) in methanol solution.The formulate C14H10N4O7 and RE(C14H9N4O7)3·nH2O(n=2 or 3) were determined by elemental analysis, IR, 1H NMR, 13C NMR, UV, FS and X-ray power diffraction. The research show that the ligand and the complexes belong to L*-L luminescent compounds because of their strong fluorescence characteristics, and all the three ligands were coordinated in the form of negative one value and one stable seven membered rings were formed by N atom(C=N) and O atom(C-O of COOH) with the rare earth(Ⅲ).The thermal decomposition of the ligand(C14H10N4O7) and the complexes (RE(C14H9N4O7)3·nH2 O) were carried out by DSC-TGA analysis at 5K/min, 10K/min and 15K/min respectively. The Kissinger's method was used to calculate the apparent activation energies and dynamic parameters of the thermal decomposition stages of the ligand and the complexes, while Ozawa method not to do these of the complexes. The results showed that the activation energies (E) and correlation coefficient (r) of the ligand by the two methods are good linear relationships, and the ligand has a higher thermal decomposition temperature and the thermal stability than 3-aldehydosalicylic acid. Meanwhile, compared with the ligand, the higher thermal decomposition temperature and the thermal stability have been possessed by the complexes, which the apparent activation energies with the rare earth atomic number were changed in law.The biological activity of the ligand and three complexes (La(C14H9N4O7)3·2H2O, Gd(C14H9N4O7)3·3H2O, Yb(C14H9N4O7)3·3H2O) were carried out to Verticillium alboatrum reinke and Apple white mascardine fungi by the inhibition zone method, and to Escherichia coli and Bacillus subtilis by the minimal inhibitory concentration method, respectively. The results showed that the ligand and the complexes had certain bacteriostatic action on Verticillium alboatrum reinke and Apple white mascardine fungi at 60 hours, and no marked bacteriostatic activity against Escherichia coli and Bacillus subtilis. |
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