Modulate The Magnetism And Structure Of Rare Earth Complexes

Molecular Rare Earth complexes are attracting intense interest because they possess potential applications in luminescence,catalysis,and magnetism.In terms of magnetism,complexes of Tb^?,Ho^?and especially Dy^?were extensively researched as SMMs over the past few years,which have become a research hot spot.In this paper,wehavesynthesizedtwelvecomplexes,inwhichligandsare8-hydroxyquinoline derivatives and?-diketone.And we have measured the structure and magnetic of these complexes.The main research results of this paper are as follows:1.Ninetetranuclearlinearcomplexes,[RE₄?dbm?₈L₂?DMF?₂]·mCH₃CN·nCH₂Cl₂?RE=Y?1?,Tb?2?,Dy?3?,Ho?4?,Er?5?,Lu?6??and[RE₄?dbm?₈L₂?C₂H₅OH?₂]·mCH₃CN?RE=Tb?7?,Dy?8?,Ho?9??have been achieved by using of 2-[?2-hydroxyimino?-propionhydrazide)methyl]-8-hydroxyquinoline?HL?and dibenzoylmethane as ligands.Single-crystal X-ray diffraction analysis reveals that 1-9 are tetranuclear complexes and crystallize in a monoclinic unit cell with the P2₁/n space group.2.The magnetic studies reveal that two Dy^?complexes exhibit different magnetic relaxation behaviors.The out-of phase????signals of complex 8 in ac magnetic susceptibility demonstrate a clear frequency dependence,but no peak maxima are observed under 0 dc field.Whereas frequency dependence of the in-phase????and out-of phase????signals are observed and both peak maxima are observed for3 under 0 dc field,furthermore,ac susceptibility curves for complex 3 show a clear frequency dependence with two obvious peaks under a dc field of 1500 Oe.Interestingly,these data highlight the presence of not one but two relaxation processes.And complex 3 with the anisotropic barrier of 35.41 K and pre-exponential factor?₀=8.315×10^-7s.3.Two complexes[Dy₂L₄]·DMF?10?and[Er₂L₂?tfa?₄]·2CH₃CN·CH₂Cl₂?11?havebeensynthesized,with2-?2-oxime-propionylhydrazide?methyl-8-hydroxyquinoline?HL?as ligand,and trichloroacety lacetone salt?RE?tfa?₃·2H₂O?as metal ions.Single-crystal X-ray diffraction analysis reveals that the stractures of these two complexes are different.The complex 10 is crystallize in a monoclinic unit cell with the P2₁/n space group.While complex 11 is composed of two 8-coordinated Er^?ions and crystallize in a triclinic unit cell with the P?space group.4.[Tb₄L₂?hfac?₈?DMF?₂]?12?hasbeenachievedbyusingof2-[?2-hydroxyimino?-propionhydrazide)methyl]-8-hydroxyquinoline?HL?and hexaluorine acetylacetone as ligands.Single-crystal X-ray diffraction analysis reveals that the stracture of complex 12 is similar to complexes 1-9.complex 12 is tetranuclear complex and crystallize in a monoclinic unit cell with the P2₁/c space group.