Weak Ligand-Field Effect from Ancillary Ligands on Enhancing Single-Ion Magnet Performance

Yin-Shan Meng; Yi-Quan Zhang; Zhe-Ming Wang; Bing-Wu Wang; Song Gao

doi:10.1002/chem.201601934

Weak Ligand-Field Effect from Ancillary Ligands on Enhancing Single-Ion Magnet Performance

Chemistry. 2016 Aug 26;22(36):12724-31. doi: 10.1002/chem.201601934. Epub 2016 Jul 15.

Authors

Yin-Shan Meng¹, Yi-Quan Zhang², Zhe-Ming Wang¹, Bing-Wu Wang³, Song Gao⁴

Affiliations

¹ Beijing National Laboratory of Molecular Science, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China.
² Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing, 210023, P. R. China. zhangyiquan@njnu.edu.cn.
³ Beijing National Laboratory of Molecular Science, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China. wangbw@pku.edu.cn.
⁴ Beijing National Laboratory of Molecular Science, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China. gaosong@pku.edu.cn.

PMID: 27417884
DOI: 10.1002/chem.201601934

Abstract

A series of bis-pentamethylcyclopentadienyl-supported Dy complexes containing different ancillary ligands were synthesized and characterized. Magnetic studies showed that 1 Dy [Cp*2 DyCl(THF)], 1 Dy' [Cp*2 DyCl2 K(THF)]n , 2 Dy [Cp*2 DyBr(THF)], 3 Dy [Cp*2 DyI(THF)] and 4 Dy [Cp*2 DyTp] (Tp=hydrotris(1-pyrazolyl)borate) were single-ion magnets (SIMs). The 1D dysprosium chain 1 Dy' exhibited a hysteresis at up to 5 K. Furthermore, 3 Dy featured the highest energy barrier (419 cm(-1) ) among the complexes. The effects of ancillary ligands on single-ion magnetic properties were studied by experimental, ab initio calculations and electrostatic analysis methods in detail. These results demonstrated that the QTM rate was strongly dependent on the ancillary ligands and that a weak equatorial ligand field could be beneficial for constructing Dy-SIMs.

Keywords: ab initio calculations; ancillary ligands; magnetic anisotropy; magnetic properties; single-ion magnets.