Experimental Determination of Magnetic Anisotropy in Exchange‐Bias Dysprosium Metallocene Single‐Molecule Magnets. Issue 31 (29th May 2020)

• Record Type: Journal Article
• Authors: Meng, Yin‐Shan; Xiong, Jin; Yang, Mu‐Wen; Qiao, Yu‐Sen; Zhong, Zhi‐Qiang; Sun, Hao‐Ling; Han, Jun‐Bo; Liu, Tao; Wang, Bing‐Wu; Gao, Song
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 31(2020)
• Page Start: 13037
• Page End: 13043
• Publication Date: 2020-05-29
• Subjects: angular-resolved magnetometry -- dysprosium metallocene -- Magnetic anisotropy -- single-molecule magnets; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202004537
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: We investigate a family of dinuclear dysprosium metallocene single‐molecule magnets (SMMs) bridged by methyl and halogen groups [Cp′2 Dy( μ ‐X)]2 (Cp′=cyclopentadienyltrimethylsilane anion; 1 : X=CH3 − ; 2 : X=Cl − ; 3 : X=Br − ; 4 : X=I − ). For the first time, the magnetic easy axes of dysprosium metallocene SMMs are experimentally determined, confirming that the orientation of them are perpendicular to the equatorial plane which is made up of dysprosium and bridging atoms. The orientation of the magnetic easy axis for 1 deviates from the normal direction (by 10.3°) due to the stronger equatorial interactions between Dy III and methyl groups. Moreover, its magnetic axes show a temperature‐dependent shifting, which is caused by the competition between exchange interactions and Zeeman interactions. Studies of fluorescence and specific heat as well as ab initio calculations reveal the significant influences of the bridging ligands on their low‐lying exchange‐based energy levels and, consequently, low‐temperature magnetic properties. Abstract : The single‐molecule magnets (SMMs) [Cp′2 Dy( μ ‐X)]2 (Cp′=cyclopentadienyltrimethylsilane anion; X=CH3 −, Cl −, Br −, I − ) are investigated. For the first time, the magnetic easy axes of dysprosium metallocene SMMs are experimentally determined, confirming that they are oriented perpendicular to the equatorial plane which is made up of dysprosium and bridging atoms.