title: Symmetry-Supported Magnetic Blocking at 20 K in Pentagonal Bipyramidal Dy(III) Single-Ion Magnets.
abstract: 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.
authors.affiliation: Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, P. R. China.
authors.forename: Yan-Cong
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, P. R. China.
authors.forename: Jun-Liang
authors.initials: JL
authors.lastname: Liu
authors.affiliation: Theory of Nanomaterials Group and INPAC-Institute of Nanoscale Physics and Chemistry, Katholieke, Universiteit Leuven , 3001 Leuven, Belgium.|Theoretical Chemistry, Lund University , 22241 Lund, Sweden.
authors.forename: Liviu
authors.initials: L
authors.lastname: Ungur
authors.affiliation: Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, P. R. China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, P. R. China.
authors.forename: Quan-Wen
authors.initials: QW
authors.lastname: Li
authors.affiliation: Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, P. R. China.
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Wang
authors.affiliation: Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, P. R. China.
authors.forename: Zhao-Ping
authors.initials: ZP
authors.lastname: Ni
authors.affiliation: Theory of Nanomaterials Group and INPAC-Institute of Nanoscale Physics and Chemistry, Katholieke, Universiteit Leuven , 3001 Leuven, Belgium.
authors.forename: Liviu F
authors.initials: LF
authors.lastname: Chibotaru
authors.affiliation: Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, P. R. China.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Chen
authors.affiliation: Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou 510275, P. R. China.
authors.forename: Ming-Liang
authors.initials: ML
authors.lastname: Tong