Liu Cai-Ming, Zhang De-Qing, Hao Xiang, Zhu Dao-Ben
Beijing National Laboratory for Molecular Sciences, Institution of Chemistry, Chinese Academy of Sciences, Center for Molecular Sciences, Beijing 100190 (P.R. China), Fax: (+86) 010-62569349.
Chem Asian J. 2014 Jul;9(7):1847-53. doi: 10.1002/asia.201402001. Epub 2014 May 7.
The Schiff base ligand N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H(2)valdien) and the co-ligand 6-chloro-2-hydroxypyridine (Hchp) were used to construct two 3d-4f heterometallic single-ion magnets [Co(2) Dy(valdien)2 (OCH(3))(2) (chp)(2)]⋅ClO(4)⋅5 H(2)O 1 and [Co(2) Tb(valdien)(2) (OCH(3))(2)(chp)(2)]⋅ClO(4)⋅(2) H(2)O⋅CH(3)OH(2). The two trinuclear [Co(III) 2 Ln(III)] complexes behave as a mononuclear Ln(III) magnetic system because of the presence of two diamagnetic cobalt(III) ions. Complex 1 has a molecular symmetry center, and it crystallizes in the C2/c space group, whereas complex 2 shows a lower molecular symmetry and crystallizes in the P(2)1/c space group. Magnetic investigations indicated that both complexes are field-induced single-ion magnets, and the Co(III)(2)-Dy(III) complex possesses a larger energy barrier [74.1(4.2) K] than the Co(III)(2) -Tb(III) complex [32.3(2.6) K].
席夫碱配体N1,N3-双(3-甲氧基水杨醛)二乙烯三胺(H₂valdien)和共配体6-氯-2-羟基吡啶(Hchp)被用于构建两个3d-4f异金属单离子磁体[Co₂Dy(valdien)₂(OCH₃)₂(chp)₂]⋅ClO₄⋅5 H₂O 1和[Co₂Tb(valdien)₂(OCH₃)₂(chp)₂]⋅ClO₄⋅(2) H₂O⋅CH₃OH₂。这两个三核[Co(III)₂Ln(III)]配合物由于存在两个抗磁性钴(III)离子而表现为单核Ln(III)磁体系。配合物1具有分子对称中心,它结晶于C2/c空间群,而配合物2显示出较低的分子对称性且结晶于P(2)1/c空间群。磁性研究表明这两个配合物都是场诱导单离子磁体,并且Co(III)₂-Dy(III)配合物比Co(III)₂-Tb(III)配合物[32.3(2.6) K]具有更大的能垒[74.1(4.2) K]。