Symmetry-Supported Magnetic Blocking at 20 K in Pentagonal Bipyramidal Dy(III) Single-Ion Magnets

• Published in: Journal of the American Chemical Society Vol. 138; no. 8; pp. 2829 - 2837
• Main Authors: Chen, Yan-Cong, Liu, Jun-Liang, Ungur, Liviu, Liu, Jiang, Li, Quan-Wen, Wang, Long-Fei, Ni, Zhao-Ping, Chibotaru, Liviu F, Chen, Xiao-Ming, Tong, Ming-Liang
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 02.03.2016
• Subjects: energy; ethanol; hysteresis; magnetic materials; magnetism; phosphine; temperature
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/jacs.5b13584

Single-molecule magnets (SMMs) that can be trapped in one of the bistable magnetic states separated by an energy barrier are among the most promising candidates for high-density information storage, quantum processing, and spintronics. To date, a considerable series of achievements have been made. However, the presence of fast quantum tunnelling of magnetization (QTM) in most SMMs, especially in single-ion magnets (SIMs), provides a rapid relaxation route and often sets up a limit for the relaxation time. Here, we pursue the pentagonal bipyramidal symmetry to suppress the QTM and present pentagonal bipyramidal Dy­(III) SIMs [Dy­(Cy3PO)2(H2O)5]­Cl3·(Cy3PO)·H2O·EtOH (1) and [Dy­(Cy3PO)2(H2O)5]­Br3·2­(Cy3PO)·2H2O·2EtOH (2), (Cy3PO = tricyclohexyl phosphine oxide). Magnetic characterizations reveal their fascinating SMM properties with high energy barriers as 472(7) K for 1 and 543(2) K for 2, along with a record magnetic hysteresis temperature up to 20 K for 2. These results, combined with the ab initio calculations, offer an illuminating insight into the vast possibility and potential of what the symmetry rules can achieve in molecular magnetism.