节点文献
稀土芳香羧酸配合物的合成、晶体结构及抑菌活性研究
Synthesis, Crystal Structure and Antimicrobial Properties of Rare Earths Aromatic Carboxylic Acid Complexes
【作者】 陈志民；
【导师】 王瑞芬；
【作者基本信息】 河北师范大学 ， 无机化学， 2009， 硕士
【摘要】 本论文以7种芳香羧酸和1,10-邻菲啰啉为配体,合成了4种稀土（La,Pr,Y,Yb）的28种三元配合物。利用EDTA配位滴定和元素分析（C、H、N）,初步确定了它们的组成。运用IR、TG-DTG、抑菌活性实验等手段,对这些配合物进行了初步的结构表征和性质研究。配合物中,稀土离子与羧基中的氧原子和1,10-邻菲啰啉中的氮原子形成了稳定的化学键。这些配合物具有较好的热稳定性,由于RE-N化学键的稳定性较差,所以配体phen的失去温度较低,而芳香羧酸配体的失去温度较高。配合物的热分解最终（?）为对应的稀土氧化物。用X-射线单晶衍射方法,测定了4个配合物[La（o-MBA）3phen]2·H2O（Ⅰ）、[Pr（o-MOBA）3phen·H2O]2·3H2O（Ⅱ）、Pr（m-MOBA）3phen（Ⅲ）和Yb（m-MBA）3phen（Ⅳ）的晶体结构。它们均以双核分子形式存在,配合物Ⅰ～Ⅲ属于三斜晶系,P（?）空间群;配合物Ⅳ属于单斜晶系,P2（1）/c空间群。在这4个配合物中,1,10-邻菲啰啉配体以端基螯合的方式用两个氮原子与一个中心稀土离子配位,而芳香羧酸配体中的羧基与中心稀土离子的配位包括端基单齿、端基螯合双齿、桥联双齿和桥联三齿四种不同的方式。稀土氯化物、芳香羧酸配体、邻菲啰啉和28种稀土三元配合物的抑菌活性对比实验表明,配合物的抑菌活性均强于相应稀土氯化物,也基本上强于相应羧酸配体。抑菌活性实验数据表明,28种稀土配合物中对大肠杆菌的抑制作用最强的是Y（p-MBA）3phen·H2O,最弱的是Yb（p-MOBA）3phen;对金黄色葡萄球菌的抑制作用最强（?）（p-MBA）3phen和Yb（o-MBA）3phen,最弱的是Yb（BA）3phen。所有这些研究,为进一步研制新型、高效的稀土芳香羧酸抑菌材料和稀土抗菌药物提供了重要的科学依据。
【Abstract】 A series of ternary complexes of RE（Ⅲ）（La,Pr,Y,Yb） were synthesized with seven kinds of aromatic carboxylic acids and 1,10-phenanthroline as ligands.The compositions of these complexes were initially defined by elemental analysis（C,H,N） and EDTA titration for rare earth.These complexes were characterized by means of IR,TG-DTG,and bacteriostatic activity methods.In these complexes,the rare earth ions were bonded to the oxygen atoms of carboxylate and the nitrogen atoms of neutral phen ligand.All of these complexes show fine thermal stability.The structures of four ternary complexes[La（o-MBA）3phen]2·H2O（Ⅰ）, [Pr（o-MOBA）3phen·H2O]2·3H2O（Ⅱ）,Pr（m-MOBA）3phen（Ⅲ） and Yb（m-MBA）3phen（Ⅳ） have been determined using X-ray diffraction.All of the complexes exist as binuclear molecules,Ⅰ～Ⅲcrystallize in triclinic,space group P（?）;Ⅳbelongs to monoclinic,space group P2（1）/c.The antibacterial properties of twenty-eight aromatic carboxylic acids complexes,rare earths chloride and organic ligands were studied.The results indicate that the complexes show better antibacterial activities to Escherichia Coli and Staphylococcus aureus than the corresponding rare earths chloride.The antibacterial activity of complex Y（p-MBA）3phen·H2O is the highest against Escherichia Coli,and Yb（p-MOBA）3phen is the weakest against Escherichia Coli,while the complexes Yb（p-MBA）3phen and Yb（o-MBA）3phen is the highest against Staphylococcus aureus,and Yb（BA）3phen is the weakest against Staphylococcus aureus.These results would provide valuable information for the synthesis of new effective rare earth bacteriostat and antibacterial drugs.
【Key words】 Rare earth； Complex； Aromatic carboxylic acid； Crystal structure； Bacteriostatic activity；