二苯羧酸类稀土配合物对藤黄微球菌抑制作用的微量热研究

摘要

Four isostructural rare earth complexes, namely [Re2(oba)3(H2O)5]·H2O[Re=La(1), Ce(2), Sm(3), Er(4), H2oba=4,4′-oxybisbenzoic acid], have been synthesized under solvothermal conditions and characterized by elemental analysis, infrared(IR) spectrometry, and powder X-ray diffraction.Thermogravimetric analysis demonstrates that these complexes possess good thermostability.Micrococcus luteus inhibition by these complexes have been real-time detected by means of microcalorimetry.The growth rate constant k, maximum power Pmax, passage time tG and inhibitive ratio I, respectively, have been obtained.Experimental results indicate that the title complexes present effective inhibition on Micrococcus luteus, and the order is listed as follows:[Er2(oba)3(H2O)5]·H2O(4)>[Sm2(oba)3(H2O)5]·H2O(3)>[Ce2(oba)3(H2O)5]·H2O(2)>[La2(oba)3(H2O)5]·H2O(1).%合成了4例二苯羧酸类稀土配合物:[Re2(oba)3(H2O)5]·H2O[Re=La(1)、Ce(2)、Sm(3)、Er(4)](oba=4,4′-二羧基二苯基醚),利用元素分析、红外光谱和粉末X射线衍射等技术手段对其结构及组成进行了表征,热重分析表明,4例配合物具有良好的热稳定性. 采用微量热法,实时跟踪监测4种目标配合物对藤黄微球菌的抑制作用,得到了热谱曲线. 依据热动力学模型对热谱曲线进行解析,计算了生长和抑制过程的热动力学函数,在不同浓度配合物存在时,获得了细菌生长速率常数(k)、最大产热功率(Pmax)、传代时间(tG)以及抑制率(I)等参数. 结果表明,4种配合物对藤黄微球菌均具有抑制作用,抑菌效果依次为:[Er2(oba)3(H2O)5]·H2O(4)>[Sm2(oba)3(H2O)5]·H2O(3)>[Ce2(oba)3(H2O)5]·H2O(2)>[La2(oba)3(H2O)5]·H2O(1).