Insight into D6h Symmetry: Targeting Strong Axiality in Stable Dysprosium(III) Hexagonal Bipyramidal Single-Ion Magnets
Insight into D6h Symmetry: Targeting Strong Axiality in Stable Dysprosium(III) Hexagonal Bipyramidal Single-Ion Magnets
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DOI：
10.1002/anie.201907686
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发表时间：
2019-08-22
影响因子：
16.6
通讯作者：
Murrie, Mark
中科院分区：
文献类型：
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作者：
Canaj, Angelos B.;Dey, Sourav;Murrie, Mark
遵循一种新的合成策略，其中由Ph_3SiO-(Ph_3SiO-=三苯基硅醇的阴离子)和2，4-二Bu-t-Pho-(2，4-di-Bu-t-pho-=2，4-二叔丁基苯酚的阴离子)配体产生的强单轴配位场与配体L-N6的弱赤道场相结合，导致[Dy-III(L-N6)(2，4-diBu-t-pho)(2)](Pf6)(1)，[Dy-III(L-N6)(Ph_3SiO)(2)](Pf_6)(2)和[Dy-III(L-N_6)(Ph_3SiO)(2)](BPh_4)(3)六方双锥体镝(III)单分子磁体(SMM)在零场下具有高各向异性势垒U-ff=973K(1)，U-ff=1080K(2)和U-ff=1124K(3)。从头算预测，这些化合物的主导磁化反转势垒将扩展到3Kramers双重态，从而首次揭示了即使是赤道六个施主原子也未能抵消的特殊单轴磁各向异性，从而为其他高阶对称SMM开辟了可能性。
Following a novel synthetic strategy where the strong uniaxial ligand field generated by the Ph3SiO- (Ph3SiO-=anion of triphenylsilanol) and the 2,4-di-Bu-t-PhO- (2,4-di-Bu-t-PhO-=anion of 2,4-di-tertbutylphenol) ligands combined with the weak equatorial field of the ligand L-N6, leads to [Dy-III(L-N6)(2,4-di-Bu-t-PhO)(2)](PF6) (1), [Dy-III(L-N6)(Ph3SiO)(2)](PF6) (2) and [Dy-III(L-N6)(Ph3SiO)(2)](BPh4) (3) hexagonal bipyramidal dysprosium(III) single-molecule magnets (SMMs) with high anisotropy barriers of U-eff=973 K for 1, U-eff=1080 K for 2 and U-eff=1124 K for 3 under zero applied dc field. Ab initio calculations predict that the dominant magnetization reversal barrier of these complexes expands up to the 3rd Kramers doublet, thus revealing for the first time the exceptional uniaxial magnetic anisotropy that even the six equatorial donor atoms fail to negate, opening up the possibility to other higher-order symmetry SMMs.