A Trigonal-Pyramidal Erbium(III) Single-Molecule Magnet

• Published in: Angewandte Chemie International Edition Vol. 54; no. 20; pp. 5864 - 5868
• Main Authors: Brown, Andrew J., Pinkowicz, Dawid, Saber, Mohamed R., Dunbar, Kim R.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 11-05-2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Elongation; erbium; Hysteresis; Lanthanides; Ligands; Magnetic fields; magnetic hysteresis; Magnetic permeability; Magnetic properties; Magnetization; mononuclear; prolate lanthanides; Riding; single-molecule magnets; prolate lanthanides; erbium; magnetic hysteresis; single-molecule magnets; mononuclear
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201411190

Given the recent advent of mononuclear single‐molecule magnets (SMMs), a rational approach based on lanthanides with axially elongated f‐electron charge cloud (prolate) has only recently received attention. We report herein a new SMM, [Li(THF)4[Er{N(SiMe3)2}3Cl]⋅2 THF, which exhibits slow relaxation of the magnetization under zero dc field with an effective barrier to the reversal of magnetization (ΔEeff/kB=63.3 K) and magnetic hysteresis up to 3 K at a magnetic field sweep rate of 34.6 Oe s−1. This work questions the theory that oblate or prolate lanthanides must be stabilized with the appropriate ligand framework in order for SMM behavior to be favored.
Riding the wave of erbium SMMs: The first trigonal pyramidal mononuclear erbium(III) single‐molecule magnet (SMM) was synthesized and its magnetic properties investigated. Despite containing an axial Cl− ligand, which is expected to reduce the prolate nature of the erbium(III) ion, the molecule exhibits out‐of‐phase signals in the ac susceptibility data in the absence of an external field and hysteresis behavior up to 3 K.