Barta Cheri A, Bayly Simon R, Read Paul W, Patrick Brian O, Thompson Robert C, Orvig Chris
Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
Inorg Chem. 2008 Apr 7;47(7):2294-302. doi: 10.1021/ic701613x. Epub 2008 Mar 5.
Five new trinuclear Cu-Ln-Cu cluster complexes have been prepared by a one-pot reaction using H3bcn (tris- N,N',N''-(2-hydroxybenzyl)-1,4,7-triazacyclononane) and Ln = La(III), Nd(III), Gd(III), Dy(III), and Yb(III) where the d- and f-block metal ions are in close proximity desirable for magnetic studies. The [LnCu2(bcn)2]ClO4.nH2O complexes possess the same stoichiometry as the previously reported [LnNi2(bcn)2]ClO4.nH2O and [LnZn2(bcn)2]ClO4.nH2O systems. Additionally, the solid state structures of the LnCu2 complexes appear to be isostructural to the LnNi2 and LnZn2 species as determined by their nearly superimposable IR spectra. The similarities in the structures of the [LnTM2(bcn)2]ClO4.nH2O series, where TM = Zn(II), Ni(II), and Cu(II), allow for direct comparison of their magnetic exchange. An empirical approach, removing first-order anisotropic contributions determined from the analogous [LnZn2(bcn)2]ClO4.nH2O was used to study the d/f/d spin interactions in the [LnCu2(bcn)2]ClO4.nH2O complexes. A ferromagnetic exchange was determined where Ln = Gd(III), Dy(III), or Yb(III) and an antiferromagnetic exchange for Ln = Nd(III), identical to the magnetic exchange observed for the [LnNi2(bcn)2]ClO4.nH2O complexes. An exchange integral of 3.67 cm(-1) for the trimetallic [GdCu2(bcn)2]ClO4.3H2O species was determined using a modified spin Hamiltonian. The [Cu(Hbcn)] and the Cu3(Hbcn)22 building blocks of the larger coaggregated d/f/d species were also synthesized, and their structures are reported.
通过一锅法反应，使用H3bcn（三 - N，N'，N'' - （2 - 羟基苄基） - 1,4,7 - 三氮杂环壬烷）和Ln = La(III)、Nd(III)、Gd(III)、Dy(III)以及Yb(III)制备了五种新型三核Cu - Ln - Cu簇合物，其中d族和f族金属离子紧密相邻，这对于磁性研究是理想的。[LnCu2(bcn)2]ClO4·nH2O配合物与先前报道的[LnNi2(bcn)2]ClO4·nH2O和[LnZn2(bcn)2]ClO4·nH2O体系具有相同的化学计量比。此外，通过近乎重叠的红外光谱确定，LnCu2配合物的固态结构似乎与LnNi2和LnZn2物种同构。[LnTM2(bcn)2]ClO4·nH2O系列（其中TM = Zn(II)、Ni(II)和Cu(II)）结构上的相似性使得可以直接比较它们的磁交换。采用一种经验方法，去除由类似的[LnZn2(bcn)2]ClO4·nH2O确定的一阶各向异性贡献，用于研究[LnCu2(bcn)2]ClO4·nH2O配合物中的d/f/d自旋相互作用。确定当Ln = Gd(III)、Dy(III)或Yb(III)时存在铁磁交换，而当Ln = Nd(III)时存在反铁磁交换，这与在[LnNi2(bcn)2]ClO4·nH2O配合物中观察到的磁交换相同。使用修正的自旋哈密顿量确定三金属[GdCu2(bcn)2]ClO4·3H2O物种的交换积分是3.67 cm(-1)。还合成了较大的聚集d/f/d物种的[Cu(Hbcn)]和Cu3(Hbcn)22结构单元，并报道了它们的结构。
