Study On The Synthesis And Properties Of Two Types Of Lanthanide Complexes Based On Aryldicarboxylate Or Their Acylhydrazone Derivative

In recent years,the development of Ln-complexes is becoming more and more diversified.Ln-MOFs fluorescent probes take the advantages of large Stokes shift and long fluorescence lifetime.They also could eliminate the influence of background effectively.Thus design and synthesis Ln-MOFs fluorescent probe have attracted attention in the field of supramolecular chemistry,owing to their high sensitivity,high efficiency and high selectivity.On the other hand,single molecule magnets(SMMs)have potential applications in various fields of high data storage,quantum computing devices and spintronics,etc.Especially,the acylhydrazone ligands bear many coordinative sites,good coordination ability,which has shown promising potential in the synthesis of SMMs based on polynuclear Ln cluster.In this context and comblined with previous work of our group,we study the Fe3+ ion sensing properties ofthree series Ln-MOFs material,considering the fluorescence spectrum and the non-coordinating oxygen atoms in these MOFs.Meanwhile,we synthesis a series polynuclear of cluster with a novel acylhydrazones ligands of pyridine salicylaldehyde-pyridine-2,6-dimethyhydrazones-N-oxide(H4sapho).Their structures and magnetic properties were also investigated.The research contents were shown as follows:1.On the basis of characteristic fluorescence spectrum of three cases of Ln-MOFs,their Fe3+ions sensing properties were investigated.The results indicated that three of them can detected Fe3+ ions efficiently and sensitively and a very small concentration of Fe3+ ions in the solution(10-6 mol/L)could result in a dramatically decreased luminescence intensity,which is consider to be dynamic quenching processes.The ICP and PXRD were then employed to probe their sensing mechanism,,which reveal that all the Ln-MOFs material remains intact in Fe3+solution,..2.The solvothermal reactions of Ln(OAc)3·6H2O with the H4sapho afforded two Ln polynuclear clusters,namely,[Dy?12(sapho)4(OAc)12(?3-OH)8(H2O)2]·4CH3OH,[Ln=Dy(4),Er(5)].Theses clusters contain four kinds coordination environments of Ln3+ ions.All the ligands display ?4-?1:?1:?2:?2:?2:?1:?1 mode,which cross with each other to chelate twelve Ln3+ ions.The Ooxynitride bridge other Ln3+,contributing to the formation of the polynuclear cluster structures.What noteworthy is that the OAc-ions with display ?2-?1:?2 and ?2-?1:?1 modes act as an auxiliary bridging ligand.The magnetic investigation revealed that 4 show slow magnetic relaxation,indicative of SMMs behaviors.