| Summary: | 碩士 === 國立成功大學 === 化學系 === 102 === This work contains three parts. The first part, a series of heterometallic 3d-4f dinuclear [NiIILnIII(pppd)2(NO3)3(H2O)(MeCN)]•H2O (Ln = Y (1), Gd (2), Tb (3), Dy (4), Ho (5)) complexes have been synthesized by using multidentate ligand, 1-phenyl-3-(pyridin-2-yl)propane-1,3-dione (Hpppd), and Ni(II), Dy(III) metal ions. The structures of these compounds were determined by X-ray crystallography. Structural studies demonstrate that the metal centers in these complexes are bridged by two β-diketone ligands, leading to a [NiIILnIII(μ-O)2] core, and also show that Ni ions are with hexacooridinate in octahedral environments and lanthanide ions possess a distorted monocapped square antiprism geometry. Direct current (dc) magnetic susceptibility measurements reveal the presence of intramolecular ferromagnetic interactions in complexes 2•Gd4•Dy. Alternating current magnetic susceptibility data indicate complex 4•Dy exhibits slow relaxations of the magnetization, which could be valuable candidate for SMM behavior. In the second part, a novel series of 3d-4f trinuclear [NiII2LnIII(nppd)(Hsae)2(NO3)(OAc)2(μ3-OMe)]•H2O•2MeOH (Ln = Y (6), Gd (7), Tb (8), Dy (9), Ho (10)) complexes have been obtained by using 1-(naphthalen-2-yl)-3-(pyridin-2-yl)propane-1,3-dione (Hnppd) and Schiff based ligand (H2sae= N-salicylidene-2-aminoethanol) and Ni(II), Dy(III) metal ions. The structures of these compounds were determined by X-ray crystallography. Two NiII and one LnIII atoms are in a nearly isosceles, triangular arrangement. Direct current magnetic susceptibility measurements reveal the presence of ferromagnetic interaction between NiII and LnIII in complexes 7•Gd–10•Ho. Alternating current magnetic susceptibility data indicate complex 9•Dy and 10•Ho exhibit slow relaxation of the magnetization because of the presence of a magnetic anisotropy brought by the dysprosium(III) ions and holmium(III). The third part, two isostructural dinuclear lanthanide complexes [LnIII2(Hsal)3(mppd)3(H2O)2] (Ln = Dy (11), Ho (12)) complexes have been synthesized by using multidentate ligand, 1-methyl-3-(pyridin-2-yl)propane-1,3-dione (Hnppd), Salicylic acid (H2sal) and Ln(NO3)2•xH2O metal ion. The structures of these compounds were determined by X-ray crystallography. Direct current magnetic susceptibility measurements reveal the presence of weakly antiferromagnetic interactions between Ln…Ln ions in complexes 11•Dy12•Ho. Alternating current magnetic susceptibility data indicate complex 11•Dy and 12•Ho exhibit slow relaxation of the magnetization.
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