异双希夫碱与La(Ⅲ)配合物的合成、热分解反应动力学和抑菌活性

Synthesis,Thermodecomposition Kinetics and Abacterial Activity of a La(Ⅲ)Complex with an Unsymmetrical Schiff Base

研究稀土配合物在催化及生命科学领域的应用,以L 赖氨酸与水杨醛、糠醛作用合成了1种异双希夫碱配体C18H19O4N2 Li(HLLi)。在异丙醇和甲醇体系中硝酸镧与该配体反应合成了1种稀土希夫碱配合物[La(HL) (NO3 ) ]NO3 ·2H2 O。通过元素分析、IR ,UV ,TG DTG及摩尔电导分析等手段对合成的配合物进行了表征,用非等温热重法研究了镧配合物的热分解动力学,推断出第二步热分解的动力学方程,并计算出了活化熵ΔS≠和活化吉布斯自由能ΔG≠。对配合物的抑菌活性进行了初步研究,结果表明配合物比配体具有更高的抑菌活性。

A new unsymmetrical Schiff base ligand (HLLi) was synthesized using L-lysine, salicylaldehyde and furfural. A new solid La(Ⅲ) complex of this ligand [La(HL)(NO 3)]NO 3·2H 2O has been prepared and characterized by elemental analyses, IR spectra, UV spectra and molar conductance analyses. The thermal decomposition kinetics of the complex in the second stage was studied under non-isothermal conditions by TG and DTG methods. The kinetic equations may be expressed as: dα/dt=A·e -E/RT ·f(α)=A·e -E/RT ·(1-α) 2. The antibacterial activity of the ligand and its complex was also studied. The result indicates that both the Schiff base and its complex have antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis and the complex shows higher activity than the ligand.