Importance of an axial LnIII–F bond across the lanthanide series and single-molecule magnet behavior in the Ce and Nd analogues

Regincós Martí, E., Canaj, A. B. , Sharma, T., Celmina, A., Wilson, C. , Rajaraman, G. and Murrie, M. (2022) Importance of an axial LnIII–F bond across the lanthanide series and single-molecule magnet behavior in the Ce and Nd analogues. Inorganic Chemistry, 61(26), pp. 9906-9917. (doi: 10.1021/acs.inorgchem.2c00556) (PMID:35727882)

Abstract

The recently reported compound [DyIIILF](CF3SO3)2·H2O (L = 1,4,7,10-tetrakis(2-pyridylmethyl)-1,4,7,10-tetraaza-cyclododecane) displays a strong axial magnetic anisotropy, due to the short axial Dy–F bond, and single-molecule magnet (SMM) behavior. Following our earlier [DyIIILF]2+ work, herein we report the systematic structural and magnetic study of a family of [LnIIILF](CF3SO3)2·H2O compounds (Ln(III) = 1-Ce, 2-Pr, 3-Nd, 4-Eu, 5-Tb, 6-Ho, 7-Er, 8-Tm, and 9-Yb). From this series, the Ce(III) and Nd(III) analogues show slow relaxation of the magnetization under an applied direct current magnetic field, which is modeled using a Raman process. Complete active space self-consistent field theoretical calculations are employed to understand the relaxation pathways in 1-Ce and 3-Nd and also reveal a large tunnel splitting for 5-Tb. Additional computational studies on model compounds where we remove the axial F– ligand, or replace F– with I–, highlight the importance of the F– ligand in creating a strong axial crystal field for 1-Ce and 3-Nd and for promoting the SMM behavior. Importantly, this systematic study provides insight into the magnetic properties of these lighter lanthanide ions.

• Item Type: Articles
• Additional Information: The UK Engineering and Physical Sciences Research Council (grant ref EP/N01331X/1) and The University of Glasgow are thanked for the financial support. G.R. would like to acknowledge DST and SERB (CRG/2018/00430; DST/ CSA-03/2018-10; SB/SJF/2019-20/12; and SPR/2019/ 001145) for funding.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Regincos Marti, Miss Emma and Murrie, Professor Mark and Wilson, Dr Claire and Tsanai, Dr Angelos
• Authors: Regincós Martí, E., Canaj, A. B., Sharma, T., Celmina, A., Wilson, C., Rajaraman, G., and Murrie, M.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Inorganic Chemistry
• Publisher: American Chemical Society
• ISSN: 0020-1669
• ISSN (Online): 1520-510X
• Published Online: 21 June 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Inorganic Chemistry 61(26): 9906-9917
• Publisher Policy: Reproduced under a Creative Commons License