Coordination anion effects on the geometry and magnetic interaction of binuclear Dy₂ single-molecule magnets

Abstract

Two new dimeric dysprosium(III) complexes [Dy2(HL)2(SCN)2]·2CH3CN (1) and [Dy2(HL)2(NO3)2]·2CH3CN·2H2O (2) have been assembled using the H3L multidentate ligand (H3L = 2,2'-((((2-hydroxy-5-methyl-1,3-phenylene)bis(methylene))bis((pyridin-2-ylmethyl)azanediyl))bis(methylene))diphenol). The use of different coordination anions for the two...

A single-ion magnet building block strategy toward Dy2single-molecule magnets with enhanced magnetic performance

“…This intermediate g zz value arises due to the differences in the local symmetry around the Dy( iii ) centers, which misaligns the g zz orientations, in contrast to typical antiferromagnetically coupled Dy 2 centrosymmetric dimers ( g zz ∼ 0). 17 a ,31 a , b ,35 For complex 3 , we have observed a very small tunnel splitting of ∼10 −5 cm −1 for the ground state, indicating the suppression of the ground state QTM. For both complexes 2–3 , we have observed a significantly smaller tunnel splitting value for ground exchange doublets compared to their single-ion analogues, which indicates that magnetic exchange interaction plays a crucial role in blocking the ground state QTM.…”

Influence of lattice water molecules on the magnetization dynamics of binuclear dysprosium(iii) compounds: insights from magnetic andab initiocalculations

“…10 Remarkably, binuclear dysprosium compounds benefiting from the large exchange coupling interactions between Dy III ions exhibit nearly complete blockage of magnetization, meaning that the QTM is suppressed effectively. 11,12 Therefore, constructing such a system with a large magnetic coupling interaction is an ideal way to achieve high energy barrier SMMs.…”

Enhancing magnetic relaxation through subcomponent self-assembly from a Dy2to Dy4grid

“…12,[34][35][36][37][38] For polynuclear SMMs, the intra-molecular magnetic couplings between Ln III ions also need to be addressed since the zerofield quantum tunnelling of magnetisation (QTM) can be effectively suppressed owing to the reduced tunnelling probability for the need to simultaneously flip two magnetic moments. [39][40][41][42][43][44][45][46][47][48][49] Of the major achievements, examples are the record blocking temperature (T B = 80 K) discovery for the mononuclear Dy III metallocene cation, namely, [(Cp iPr5 )Dy (Cp*)] + (Cp iPr5 = penta-iso-propylcyclopentadienyl, Cp* = pentamethylcyclopentadienyl) with a record anisotropy barrier of up to 2217 K, 50 and the enormous coercive magnetic field with a lower bound of 14 T, detected for a mixed-valence di-lanthanide complex [(Cp iPr5 ) 2 Dy 2 I 3 ] at temperatures as high as 60 K. 51 The subcomponent self-assembly approach reveals a more versatile and robust synthetic method compared to the use of pre-synthesis of the ligand to achieve the construction of selfassembled architectures. 52 This method has been widely adopted for the construction of functional polynuclear transition and lanthanide supramolecular architectures, and can yield desired stable aggregates with complex topologies via judicious choice of subcomponent scaffolds.…”

“…12,34–38 For polynuclear SMMs, the intra-molecular magnetic couplings between Ln III ions also need to be addressed since the zero-field quantum tunnelling of magnetisation (QTM) can be effectively suppressed owing to the reduced tunnelling probability for the need to simultaneously flip two magnetic moments. 39–49 Of the major achievements, examples are the record blocking temperature ( T B = 80 K) discovery for the mononuclear Dy III metallocene cation, namely, [(Cp iPr5 )Dy(Cp*)] + (Cp iPr5 = penta-iso-propylcyclopentadienyl, Cp* = pentamethylcyclopentadienyl) with a record anisotropy barrier of up to 2217 K, 50 and the enormous coercive magnetic field with a lower bound of 14 T, detected for a mixed-valence di-lanthanide complex [(Cp iPr5 ) 2 Dy 2 I 3 ] at temperatures as high as 60 K. 51…”