Enhancing Anisotropy Barriers of Dysprosium(III) Single-Ion Magnets
Enhancing Anisotropy Barriers of Dysprosium(III) Single-Ion Magnets
复制标题
增强镝(III)单离子磁体的各向异性势垒
DOI：
10.1002/chem.201103816
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发表时间：
2012-02-01
影响因子：
4.3
通讯作者：
Liao, Dai-Zheng
中科院分区：
文献类型：
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作者：
Chen, Gong-Jun;Guo, Yun-Nan;Liao, Dai-Zheng
单分子磁体由于其量子隧穿和分子起源的缓慢弛豫而受到广泛关注。[1]这导致了合成化学家的强烈活动，以持续制造适合物理学家详细研究的分子系统。另一个目的是生产和表征新的分子，目的是与最初研究的例子相比，识别与增强其特性相关的特征。[2]高各向异性势垒SMM的竞争已逐渐扩展到新的系统中，并且镧系元素离子的使用已被指示为一种可能的策略，这是由于它们由大的未淬灭的轨道角动量引起的显著的磁各向异性，从而引起被称为单离子磁性（SIM）的积极研究领域。[3]沿着这条路线的合成努力沿着已经导致了许多单离子磁体的发现，包括镧系元素与酞菁、[4]聚氧乙烯酸盐、[5] β-二酮[6]或大环席夫碱配体的配合物，[7]甚至是有机金属镧系元素系统。[8]然而，基于镧系元素的西姆斯中磁化的弛豫动力学的完整和详细的理论图仍然不成熟，[3b]从而阻碍了用于增强这种材料的性能的合理和有效策略的开发。最近，我们能够证明由于正方形反棱柱单离子磁体[DyACHTUNGTRENNUNG（TTA）3ACHTUNGTRENNUNG（LCAP）]中的不同帽配体引起的配位球畸变。（TTA=噻吩甲酰三氟丙酮和LCAP=联吡啶（bpy）或1，10-菲咯啉（phen）），通过斜角F定量，表现出不同的磁弛豫速率，[9]强调弛豫速率对配位几何的微小扭曲极其敏感。修改可以很容易地合并
Single-molecule magnets (SMMs) have received much attention owing to their quantum tunneling and slow relaxation of molecular origin.[1] This has led to intense activity on the part of synthetic chemists to consistently manufacture molecular systems suitable for detailed study by physicists. A further aim is to produce and characterize new molecules with the goal of identifying features relevant to enhancing their properties compared with those of the originally studied examples.[2] The race for high anisotropy barrier SMMs has gradually expanded into new systems and the use of lanthanide ions has been indicated as a possible strategy due to their significant magnetic anisotropy arising from the large, unquenched orbital angular momentum, giving rise to an actively investigated field known as single-ion magnetism (SIM).[3] Synthetic efforts along this line have led to the discovery of many single-ion magnets, including lanthanide complexes with phthalocyanine,[4] polyoxometalate,[5] β-diketone [6] or macrocyclic Schiff base ligands,[7] or even organometallic lanthanide systems.[8]However, a complete and detailed theoretical picture of the relaxation dynamics of the magnetization in lanthanide based SIMs, is still immature,[3b] thereby hampering the development of a rational and efficient strategy for enhancing the properties of such materials. Recently, we were able to demonstrate that the coordination-sphere distortion due to different capping ligands in square antiprismatic single-ion magnets [DyACHTUNGTRENNUNG (TTA) 3ACHTUNGTRENNUNG (LCAP)](TTA= thenoyltrifluoroacetonate and LCAP= bipyridyl (bpy) or 1, 10-phenanthroline (phen)), quantified by the skew angle F, exhibit distinct magnetic relaxation rates,[9] highlighting that the relaxation rates are extremely sensitive to tiny distortions of the coordination geometry. Modifications can be easily incorporated