Recent Developments in Lanthanide Single‐Molecule Magnets

Abstract

Single-molecule magnets (SMMs) exhibiting slow relaxation of magnetization of purely molecular origin are highly attractive owing to their potential applications in spintronic devices, high-density information storage, and quantum computing. In particular, lanthanide SMMs have been playing a major role in the advancement of this field because of the large intrinsic magnetic anisotropy of lanthanide metal ions. Herein, some recent breakthroughs that are changing the perspective of the field are highlighted, with special emphasis on synthetic strategies towards the design of high-performance SMMs.

Pentanuclear Spirocyclic Ni4Ln Derivatives: Field Induced Slow Magnetic Relaxation in the Dysprosium and Erbium Analogues

“…Chemists have to devise appropriate organic ligands with specific functionalities for preferential aggregation of both 3d and 4f metal ions, at the same time where magnetic exchanges can occur among the metal centres via a suitable single-atom or by means of multiatom bridges. [35][36][37][38][39][40][41][42] Based on the above requirements in mind we prepared a new chelating, multisite, coordinating Schiff base ligand (E)-2-(hydroxymethyl)-6-{[(2-hydroxyphenyl)-imino] methyl}-4-methylphenol (LH 3 ), leading to the formation of heterometallic 3d/4f complexes. Hereby, we report the synthesis, structure, and magnetic characterization of five isostructural pentanuclear clusters, [Ni 4 Ln(L) 2 (LH) 2 (CH 3 CN) 3 Cl]·xH 2 O·yCH 3 OH Ln = Y III (1), Gd III (2), Tb III (3), Dy III (4) and Er III (5) {for 1 and 2, x = 2, y = 1; for 3, x = 6, y = 2; for 4, x = 5, y = 1; for 5, x = 2, y = 2} (Scheme 1).…”

Two Isostructural Layered Lanthanide(III) Complexes: Syntheses, Structures, Magnetic and Luminescent Properties

“…Lanthanide-based metal complexes constructed from different Ln III ions and diverse organic ligands have recently exhibited interesting magnetic and photophysical properties due to their strong spin-orbit coupling, large magnetic anisotropy and fluorescent f-f emissions from ultraviolet to visible and near-infrared ranges. [1][2][3] These diverse Ln-based complexes can thus be promisingly applied in the fields of chemical sensors, light-emitting devices, ultra-high density data storage, quantum computing and spintronics. [4][5][6][7] Resulting from intrinsic single-ion anisotropy, large magnetic moments and strong spin-orbit coupling of Dy III ion, lots of dysprosium(III)-based complexes behave as promisingly high-performance single molecule magnets (SMMs) with the anisotropic energy barrier (U eff ) and blocking temperature (T b ) up to 1541 cm -1 and 80 K. [8][9][10][11] Undoubtedly, the gradual improvements on the magnetic properties of these dysprosium(III)-based complexes have benefited more significantly from the crystal-field effect because of the weak intermetallic magnetic couplings.…”

Role of Ab Initio Calculations in the Design and Development of Organometallic Lanthanide‐Based Single‐Molecule Magnets

“…[11,12] Understanding the magnetic properties of lanthanides are challenging due to the close-lying energy levels called Stark levels,w hich render the interpretation of experimental data often cumbersome. Several molecules reported recently with attractive magnetic properties are known earlier,b ut their magnetic properties have been hardly explored, [13] thanks to strong anisotropy rendering most of the routine magnetic characterisation ineffective. As ignificant advancementi nt erms of interpretation and design in lanthanide SIMs arise due to the quantum chemical calculations aided by the robustd evelopment in computing hardware, enabling one to perform high-level ab initio calculationso nt hese molecules.P ioneering work by Chibotaru and co-workerso nt he development of pseudospin Hamiltonian formalism andu tilisation of the same to derive useful quantities such as crystal field splitting and the corresponding g-anisotropyo fl anthanide ions have trans-formed this area in the last decade.…”