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• 作者：Masaaki Towatari ; Koshiro Nishi ; Takeshi Fujinami ; Naohide Matsumoto ; Yukinari Sunatsuki ; Masaaki Kojima ; Naotaka Mochida ; Takayuki Ishida ; Nazzareno Re ; Jerzy Mrozinski
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：May 20, 2013
• 年：2013
• 卷：52
• 期：10
• 页码：6160-6178
• 全文大小：792K
• 年卷期：v.52,no.10(May 20, 2013)
• ISSN：1520-510X

文摘

A series of 3d鈥?f binuclear complexes, [M(3-MeOsaltn)(MeOH)_x(ac)Ln(hfac)₂] (x = 0 for M = Cu^II, Zn^II; x = 1 for M = Co^II, Ni^II; Ln = Gd^III, Tb^III, Dy^III, La^III), have been synthesized and characterized, where 3-MeOsaltn, ac, and hfac denote N,N鈥?bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, acetato, and hexafluoroacetylacetonato, respectively. The X-ray analyses demonstrated that all the complexes have an acetato- and diphenolato-bridged M^II鈥揕n^III binuclear structure. The Cu^II鈥揕n^III and Zn^II鈥揕n^III complexes are crystallized in an isomorphous triclinic space group P1̅, where the Cu^II or Zn^II ion has square pyramidal coordination geometry with N₂O₂ donor atoms of 3-MeOsaltn at the equatorial coordination sites and one oxygen atom of the bridging acetato ion at the axial site. The Co^II鈥揕n^III and Ni^II鈥揕n^III complexes are crystallized in an isomorphous monoclinic space group P2₁/c, where the Co^II or Ni^II ion at the high-spin state has an octahedral coordination environment with N₂O₂ donor atoms of 3-MeOsaltn at the equatorial sites, and one oxygen atom of the bridged acetato and a methanol oxygen atom at the two axial sites. Each Ln^III ion for all the complexes is coordinated by four oxygen atoms of two phenolato and two methoxy oxygen atoms of 鈥渓igand-complex鈥?M(3-MeOsaltn), four oxygen atoms of two hfac^{鈥?/sup>, and one oxygen atom of the bridging acetato ion; thus, the coordination number is nine. The temperature dependent magnetic susceptibilities from 1.9 to 300 K and the field-dependent magnetization up to 5 T at 1.9 K were measured. Due to the important orbital contributions of the LnIII (TbIII, DyIII) and to a lesser extent the MII (NiII, CoII) components, the magnetic interaction between MII and LnIII ions were investigated by an empirical approach based on a comparison of the magnetic properties of the MII鈥揕nIII, ZnII鈥揕nIII, and MII鈥揕aIII complexes. The differences of 蠂_MT and M(H) values for the MII鈥揕nIII, ZnII鈥揕nIII and those for the MII鈥揕aIII complexes, that is, 螖(T) = (蠂_MT)_MLn 鈥?(蠂_MT)_ZnLn 鈥?(蠂_MT)_MLa = J_MLn(T) and 螖(H) = M_MLn(H) 鈥?M_ZnLn(H) 鈥?M_MLa(H) = J_MLn(H), give the information of 3d鈥?f magnetic interaction. The magnetic interactions are ferromagnetic if MII = (CuII, NiII, and CoII) and Ln = (GdIII, TbIII, and DyIII). The magnitudes of the ferromagnetic interaction, J_MLn(T) and J_MLn(H), are in the order CuII鈥揋dIII > CuII鈥揇yIII > CuII鈥揟bIII, while those are in the order of MII鈥揋dIII 鈮?MII鈥揟bIII > MII鈥揇yIII for MII = NiII and CoII. Alternating current (ac) susceptibility measurements demonstrated that the NiII鈥揟bIII and CoII鈥揟bIII complexes showed out-of-phase signal with frequency-dependence and the NiII鈥揇yIII and CoII鈥揇yIII complexes showed small frequency-dependence. The energy barrier for the spin flipping was estimated from the Arrhenius plot to be 14.9(6) and 17.0(4) K for the NiII鈥揟bIII and CoII鈥揟bIII complexes, respectively, under a dc bias field of 1000 Oe.}