Hexanuclear Co4Dy2, Zn4Dy2, and Co4Y2 Complexes with Defect Tetracubane Cores: Syntheses,Structures, and Magnetic Properties |
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| Authors: | Dawei Li Yafei Li David Felipe Tello Yepes Xiamei Zhang Prof?Dr Yahong Li Prof?Dr Jin-lei Yao |
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| Institution: | 1. College of Chemistry, Chemical Engineering and Materials Science Soochow University, Suzhou, 215123 P. R. China;2. College of Environmental Engineering, University of Waterloo, Waterloo, N2?L3G1 Canada;3. Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, 215009 P. R. China |
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| Abstract: | A hexanuclear heterometallic cluster of composition Dy2Co4(L)4(NO3)2(OH)4(C2H5OH)2] ? 2 C2H5OH ( 1 ) was synthesized by employing a Schiff base 2-(((2-hydroxy-3-methoxybenzyl) imino)methyl)-4-methoxyphenol (H2L) as ligand and utilizing Dy(NO3)3 ? 6H2O and Co(NO3)2 ? 6H2O as metal ion sources. X-ray single-crystal diffraction analysis indicated that complex 1 contains a defect tetracubane core and possesses central symmetric structure, with two DyIII ions being in the central body position of the molecule and four CoII ions being arranged at the outer sites. Magnetic studies reveal that complex 1 behaves as single-molecule magnet (SMM) with energy barrier of 27.50 K. To investigate the individual contribution of DyIII and CoII ions to the SMM behavior, another two complexes of formulae Dy2Zn4(L)4(NO3)2(OH)4] ? 4CH3OH ( 2 ) and Y2Co4(L)4(NO3)2(OH)4(C2H5OH)2] ? 2 C2H5OH ( 3 ) were prepared. Complexes 1 and 3 are isomorphous. The coordination geometries of DyIII ions in 1 and 2 are different. The DyIII ions are eight-coordinated in 2 and nine-coordinated in 1 . Complex 2 exhibits SMM behavior with energy barrier of 69.67 K, but complex 3 does not display SMM property. These results reveal that the SMM behaviors of 1 and 2 are mainly originated from DyIII ions. It might be the higher symmetry of DyIII ions in 2 that results in the higher energy barrier. |
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| Keywords: | single-molecule magnets polynuclear heterobimetallic lanthanide ions energy barriers |
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