Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstr. 15, D-76131, Karlsruhe, Germany.
Dalton Trans. 2010 May 28;39(20):4918-27. doi: 10.1039/b926899e. Epub 2010 Apr 19.
The structures and magnetic properties of a family of new octanuclear heterometallic 3d-4f complexes [Mn(III)(4)Ln(III)(4)(mu(3)-OH)(4)(mu(2),eta(1)-X)(4)(O(2)CBu(t))(8)(t-bdea)(4)]·solv, where X = N(3)(-), Ln = Y (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6); X = OCN(-), Ln = Dy (7); X = NO(3)(-), Ln = Gd (8), Tb (9), Dy (10), Ho (11), Er (12); solv = MeCN or toluene, are reported. The metal topology in the aggregates can be described as consisting of a "Ln(4)-square inscribed in a Mn(4)-square". Complexes 1-7 are prepared by the reactions of t-butyldiethanolamine (t-bdeaH(2)) with a preformed hexanuclear manganese pivalate complex [Mn(6)], the respective lanthanide salt and either NaN(3) or NaNCO, while 8-12 are obtained from the direct reaction of Mn(OAc)(2), Ln(NO(3))(3)·xH(2)O and t-butyldiethanolamine. The magnetic properties of all the complexes were investigated using variable temperature magnetic susceptibility and magnetisation measurements. Similar magnetic behaviour was observed for compounds containing the same lanthanide, indicating that changing the bridging ligand X does not have a significant effect on the magnetic behaviour. The Tb(III) and Dy(III) compounds 4, 5, 7, 9 and 10 all show frequency-dependent ac susceptibilities indicative of a slow relaxation of magnetisation and are therefore considered as Single-Molecule Magnets.
一种新型的八核异金属 3d-4f 配合物[Mn(III)(4)Ln(III)(4)(mu(3)-OH)(4)(mu(2),eta(1)-X)(4)(O(2)CBu(t))(8)(t-bdea)(4)]·solv 的结构和磁性研究，其中 X = N(3)(-)，Ln = Y (1)，Eu (2)，Gd (3)，Tb (4)，Dy (5)，Ho (6)；X = OCN(-)，Ln = Dy (7)；X = NO(3)(-)，Ln = Gd (8)，Tb (9)，Dy (10)，Ho (11)，Er (12)；solv = MeCN 或甲苯。报道了这些配合物的结构和磁性。在配合物中，金属拓扑结构可以描述为“Ln(4)-正方形镶嵌在 Mn(4)-正方形中”。配合物 1-7 是通过 t-butyldiethanolamine(t-bdeaH(2))与预先形成的六核锰戊酸盐配合物[Mn(6)]、相应的镧系盐和 NaN(3)或 NaNCO 的反应制备的，而 8-12 则是由 Mn(OAc)(2)、Ln(NO(3))(3)·xH(2)O 和 t-butyldiethanolamine 的直接反应得到的。所有配合物的磁性都通过变温磁化率和磁化强度测量进行了研究。具有相同镧系元素的化合物表现出相似的磁性行为，表明改变桥连配体 X 对磁性行为没有显著影响。Tb(III)和 Dy(III)化合物 4、5、7、9 和 10 都表现出与频率有关的交流磁化率，表明磁化的缓慢弛豫，因此被认为是单分子磁体。
