Slow Relaxation of the Magnetization in Bis-Decorated Chiral Helicene-Based Coordination Complexes of Lanthanides

Jessica Flores Gonzalez,Nidal Saleh,Vincent Montigaud,Olivier Cador,Jeanne Crassous,Boris Le Guennic,Fabrice Pointillart

doi:10.3390/magnetochemistry4030039

Abstract

The complexes [Ln2(hfac)6(L)]·nC6H14 (Ln = Dy (1) n = 0, Yb (2) n = 1) with the L chiral 3,14-di-(2-pyridyl)-4,13-diaza[6]helicene ligand (hfac− = 1,1,1,5,5,5-hexafluoroacetylacetonate) have been synthesized in their racemic form and structurally and magnetically characterized. Both complexes behave as field-induced single molecule magnets in the crystalline phase. These magnetic properties were rationalized by ab initio calculations.

Highlights

The development of nanomaterials for high density data storage, the development of molecular Qubits/Qudits for quantum computing and spintronics is very active in the field of molecular magnetism, and both chemists and physicists communities are working hand-in-hand to make rapid progress in this field [1,2,3,4,5,6,7]
Lanthanide-based complexes are currently intensively studied, especially those displaying Single-Molecule Magnet (SMM) behavior. The interest in such species is due to the intrinsic strong magnetic anisotropy and high magnetic moment of the lanthanides [8,9,10,11,12,13,14,15]
We proposed to go one step forward by functionalizing the [6]-helicene core with two 2,2-bipyridine moieties

Summary

Introduction

The development of nanomaterials for high density data storage, the development of molecular Qubits/Qudits for quantum computing and spintronics is very active in the field of molecular magnetism, and both chemists and physicists communities are working hand-in-hand to make rapid progress in this field [1,2,3,4,5,6,7]. The main component of the ground the ground state is calculated to be mainly MJ = |±15/2> (86% MJ = |±15/2> and 11% MJ = |±11/2>, Table MagnetMocSahg5enm)etiwoscthrityehm2i0sat1r8yg,-24t0e,13n69,s2o,rx showing a stronger anisotropy character than Dy1, with gZ = 18.97 and6loofw126erof 11 transversal components (gX = 0.17 and gY = 0.33) For both magnetic centers, the main magnetic axis appears perpendicular to the plane containing the N atoms from the helicene ligand, as expected for an oblate ion in this coordination sphere [33,34]. Such an observation could be due to the specific electronic distribution caused by the bulky 3,14-di-(2-pyridyl)-4,13-diaza[6]helicene ligand

Conclusions

Synthesis General Procedures and Materials

Crystallography

Physical Measurements

Computational Details