Fine Tuning the Energy Barrier of Molecular Nanomagnets via Lattice Solvent Molecules

Cai-Ming Liu,Dao-Ben Zhu,De-Qing Zhang

doi:10.1038/s41598-017-15852-1

Cai-Ming Liu, Dao-Ben Zhu + Show 1 more

Open Access

https://doi.org/10.1038/s41598-017-15852-1

Copy DOI

Abstract

Solvents play important roles in our lives, they are also of interest in molecular materials, especially for molecular magnets. The solvatomagnetic effect is generally used for trigger and/or regulation of magnetic properties in molecule-based systems, however, molecular nanomagnets showing solvatomagnetic effects are very difficult to obtain. Here we report four 3d-4f heterometallic cluster complexes containing ROH lattice solvent molecules, [Cu3Tb2(H3L)2(OAc)2(hfac)4]∙2ROH {H6L = 1,3-Bis[tris(hydroxymethyl)methylamino]propane, hfac− = hexafluoroacetylacetonate; R = CH3, 1; R = C2H5, 2; R = C3H7, 3; R = H, 4}. Single-molecule magnet (SMM) properties of these four complexes were observed to be dependent on the ROH lattice solvent molecule. There is an interesting magneto-structural correlation: the larger the R group, the higher the energy barrier. For the first time, the solvatomagnetic effect is used for the continuous fine adjustment of the energy barrier of 0D molecular nanomagnets. Additionally, [Cu3Dy2(H3L)2(OAc)2(hfac)4]∙2MeOH (5), an analogue of [Cu3Tb2(H3L)2(OAc)2(hfac)4]∙2MeOH (1), is also reported for comparison.

Highlights

It is well known that Single-molecule magnet (SMM) are of great potential for technological applications in high-density information storage, quantum computing and spintronics[12,13,14,15,16,17]; and the energy barrier leading to magnetic bistability and slow magnetic relaxation is a pivotal parameter
Murrie et al reported a series of 3d-4f complexes formulated as {Ln2Cu3(H3L)2Xn} (X = OAc−, Ln = Gd, Tb or X = NO3−, Ln = Gd, Tb, Dy, Ho, Er)[35]; they found that changing the auxiliary ligand OAc− through NO3− may lead to a remarkable improvement of the energy barrier of {Tb2Cu3(H3L)2Xn} (X = OAc− and NO3−) complexes, which suggests that the anion co-ligand has a great impact on the energy barrier of {Tb2Cu3(H3L)2Xn} SMMs
In the recent process of pursuing new SMMs, we observed that using Ln(OAc)(hfac)2(H2O)[2] as the lanthanide (III) salt source may lead mixed co-ligands OAc− and hfac− into 3d-4f heterometallic clusters effectively[36]

Summary

Introduction

It is well known that SMMs are of great potential for technological applications in high-density information storage, quantum computing and spintronics[12,13,14,15,16,17]; and the energy barrier leading to magnetic bistability and slow magnetic relaxation is a pivotal parameter. Systematic studies of SMMs with the same magnetic structure are still rare, some factors such as the electron-withdrawing effect[27], the electrostatic potential of the key coordination atom[28] have been observed to be able to modulate SMMs’ energy barriers recently. To the best of our knowledge, a direct correlation between energy barriers and different lattice solvent molecules of 0D molecular nanomagnets has never been documented, though a 3D Dy(III) MOF-type SMM was found to show an obvious solvatomagnetic effect in 201529, and guest-dependent single-ion magnet behaviours were observed in a 2D cobalt(II) coordination polymer in 201630.

Methods

Results

Conclusion