Synthesis, Characterization, and Magnetic Properties of Copper(II)-Lanthanide(III) Heterobinuclear Complexes Bridged by N,N'-Oxamidobis(3,5-dibromobenzoato)cuprate(II)

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• 作者：Yan-Tuan Li ; Cui-Wei Yan ; and Jie Zhang
• 刊名：Crystal Growth & Design
• 出版年：2003
• 出版时间：July 2003
• 年：2003
• 卷：3
• 期：4
• 页码：481 - 485
• 全文大小：63K
• 年卷期：v.3,no.4(July 2003)
• ISSN：1528-7505

文摘

Twelve new copper(II)-lanthanide(III) heterobinuclear complexes bridged by N,N'-oxamidobis(3,5-dibromobenzoato)cuprate(II) [Cu(Br₄obbz)]^2- and end-capped with 4,4'-dimethyl-2,2'-bipyridine (Me₂bpy), namely,Cu(Br₄obbz)Ln(Me₂bpy)₂NO₃ (Ln = Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb), have been synthesized andcharacterized by elemental analyses, molar conductivity measurements, and spectroscopic (IR, UV, ESR) studies.The temperature dependence of the magnetic susceptibility of the Cu(Br₄obbz)Gd(Me₂bpy)₂NO₃ complex was furthermeasured over the range 4.2-300 K. The least-squares fit of the experimental susceptibilities based on the spinHamiltonian operator, = - 2J₁·₂, yielded J = +2.75 cm^-1. This result indicates the presence of a weakferromagnetic spin-exchange interaction between Gd(III) and Cu(II) ions. A plausible mechanism for the ferromagneticcoupling between Gd(III) and Cu(II) is discussed in terms of spin polarization.