水杨醛缩5-氨基水杨酸Schiff碱及其稀土配合物合成、表征和抑菌活性

Salicylaldehyde-5-aminosalicylic Acid Schiff Base and its Rare Earth Complexes:Synthesis,Characterization, and Bacteriostatic Activity

以水杨醛和5-氨基水杨酸为原料合成了水杨醛缩5-氨基水杨酸,并以其为配体合成了3种新的 Schiff碱稀土配合物(分别为轻Nd、中Gd和重Yb稀土配合物),通过IR、1H NMR、TG-DTA和摩尔电导等测试技术表征其结构:配体以四齿形式参与配位,配位数分别为7(Nd)和9(Gd和Yb)。抑菌活性测定结果表明,所合成的配体和配合物对金黄色葡萄球菌、大肠杆菌和枯草杆菌均表现出不同程度的抑菌效果,其中对大肠杆菌的抑菌效果最好。从整体看,无论是配体还是配合物,它们的抑菌作用都随着浓度的增大而增强。在较低浓度下,中稀土和重稀土配合物的抑菌作用比氢稀土好;在高浓度条件下,轻稀土配合物的抑菌效果好。

Salicylaldehyde-5-aminosalicylic acid Schiff base was obtained from salicylaldehyde and 5-aminosalicylic acid and Nd（ Ⅲ ）, Gd（ Ⅲ）, and Yb（ Ⅲ ） complexes with it were synthesized. Elemental analysis, molar conductance, IR, ^1H NMR, and TG-DTA measurements of the three rare earth complexes indicate that the Schiff base acts as a quadfidentate ligand and the coordination numbers are 7 for Nd ^3 ＋, and 9 for Gd^3＋ and Yb^3＋ The ligand and synthesized rare earth complexes show good bacteriostatic activities against staphyococcus aureus, escherichia cocli and withered grass bacillus. Moreover, the bacteriostatic activities of salicylal- dehyde-5-aminosalicylic acid Schiff base and its Nd（ Ⅲ ）, Gd（ Ⅲ） and Yb（ Ⅲ ） complexes are related to the rare-earth elements themselves and increased with the increase of the concentrations of the Schiff base and its complexes.