Two typical cases of magnetism for dinuclear high-spin cobalt(II) complexes in trigonal-bipyramidal fields
Two typical cases of magnetism for dinuclear high-spin cobalt(II) complexes in trigonal-bipyramidal fields
复制标题
双核高自旋钴(II)配合物在三角双锥场中磁性的两个典型案例
DOI：
10.1016/s0020-1693(02)01053-8
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发表时间：
2002
影响因子：
2.8
通讯作者：
H. Sakiyama
中科院分区：
文献类型：
--
作者：
M. Hossain;H. Sakiyama
先前发现一种无环配体1,3-二[（2-二甲氨基乙基）亚甲基]苯（baib）形成了一些双核金属配合物[金属=锰（II），钴（II）和锌（II）]，并测定了两种钴（II）配合物[Co2(baib)(MeCO2)3]BPh4(1)和[Co2(baib)(PhCO2)3]BPh4(2)的晶体结构。还进行了磁测量，但未进行磁分析。在本研究中，采用各向同性海森堡模型，g=2.30， J=−13.3 cm−1,Nα=70×10−6cm−1，对1的低温磁数据进行了较好的分析，表明地面项不具有轨道角动量。然而，另一方面，2的数据可以用所谓的Lines理论来解释，其参数为λ= - 175 cm−1,κ=0.63， J= - 1.0 cm−1，表明地面项具有轨道角动量。x射线分析发现，2中的配合阳离子[Co2(baib)(PhCO2)3]+比1中的[Co2(baib)(MeCO2)3]+扭曲得多，这可以解释这种差异。
Previously, an acyclic ligand 1,3-bis[(2-dimethylaminoethyl)iminomethyl]benzene (baib) was found to form some dinuclear metal complexes [metal=manganese(II), cobalt(II), and zinc(II)], and crystal structures of the two cobalt(II) complexes [Co2(baib)(MeCO2)3]BPh4(1) and [Co2(baib)(PhCO2)3]BPh4(2) were determined. Magnetic measurement was also carried out, but the magnetic analysis was not made. In this study, the cryomagnetic data for 1 were analyzed well by using isotropic Heisenberg model with the parameters g=2.30, J=−13.3 cm−1, and Nα=70×10−6cm−1, indicating that a ground term does not possess an orbital angular momentum. On the other hand, however, the data for 2 could be interpreted using the so-called Lines’ theory with the parameters λ=−175 cm−1, κ=0.63 and J=−1.0 cm−1, indicating that a ground term possesses an orbital angular momentum. This difference was explained by the fact that the complex cation [Co2(baib)(PhCO2)3]+in 2 was much distorted than [Co2(baib)(MeCO2)3]+in 1, as found by the X-ray analysis.