Effect of f–f interactions on quantum tunnelling of the magnetization: mono- and dinuclear Dy(iii) phthalocyaninato triple-decker single-molecule magnets with the same octacoordination environment
heterodinuclear complexes, [(NiL1)Ln(L2)(CH3OH)]·acetone (Ln = Gd (1), Tb (2), Dy (3); H3L1 = 1,1,1-tris[(salicylideneamino)methyl]ethane), were stepwise synthesized based on a thiacalix[4]arene ligand (H2L2 = 5,11,17,23-tetrakis(1,1-dimethylethyl)-25,27-dihydroxy-26,28-dimethoxy thiacalix[4]arene). In 1–3, NiII and LnIII ions are doublybridged by two phenoxo O atoms of L1. The NiII ion, only coordinated
三种异双核络合物[[(NiL 1)Ln(L 2)(CH 3 OH)]·丙酮(Ln = Gd(1),Tb(2),Dy(3); H 3 L 1 = 1,1,1 -三[[(水杨亚氨基氨基)甲基]乙烷),是根据噻唑杯[4]芳烃配体(H 2 L 2 = 5,11,17,23-四(1,1-二甲基乙基)-25,27-二羟基-26,28-二甲氧基硫杂杯[4]芳烃)。在1-3中,Ni II和Ln III离子被L 1的两个苯氧O原子双重桥接。Ni II离子,仅由L 1配位配体,具有NiN 3 O 3 }配位球;Ln III离子采用七配位的LnO 7 }环境,并以一个碗形构象的噻唑杯[4]芳烃配体封端。对所有配合物的磁性研究表明,铁离子耦合在Ni II和Ln III离子之间起作用。analogue类似物(3)在直流施加的800 Oe磁场下表现出磁场感应的单分子磁体(SMM)行为。此外,Dy:Y(1:10)磁
Impact of the coordination environment on the magnetic properties of single-molecule magnets based on homo- and hetero-dinuclear terbium(<scp>iii</scp>) heteroleptic tris(crownphthalocyaninate)
作者:Rebecca J. Holmberg、Marina A. Polovkova、Alexander G. Martynov、Yulia G. Gorbunova、Muralee Murugesu
DOI:10.1039/c6dt00777e
日期:——
field symmetry on the magnetic properties of these complexes using SQUID magnetometry. Magnetic measurements on the homonuclear TbIII complex (1) displayed non-negligible ferromagnetic coupling between magnetic ions, eliciting a high zero-field energetic barrier to the magnetic relaxation of Ueff = 229.9(0) K, while the heteronuclear TbIII/YIII complexes displayed single-ion field-induced slow relaxation
一系列Tb III三次异氰酸酯酞菁配合物,由同二核化合物[(15C5)4 Pc] Tb [(15C5)4 Pc] Tb(Pc)(1)和两种新型异双核化合物[(15C5)4 Pc组成合成了[T] [(15C5)4 Pc] Y(Pc)(2)和[(15C5)4 Pc] Y [(15C5)4 Pc] Tb(Pc)(3)。所有化合物均使用UV-Vis光谱,HR-ESI-MS,MALDI-TOF-MS和11 H NMR光谱,然后使用SQUID磁力分析法研究镧系元素偶联和配体场对称性对这些配合物的磁性的影响。对同核Tb III络合物(1)的磁性测量显示,在磁性离子之间铁磁耦合不可忽略,对U eff = 229.9(0)K的磁弛豫引起了高零场高能垒,而异核Tb III / Y III配合物显示出单离子场诱导的磁化慢弛豫;产生的高能障碍Ù EFF = 129.8(0)K为2,和169.1(8)K对于3。
The Rare Earth Metals and their Compounds. VIII. An Improved Method for the Synthesis of Some Rare Earth Acetylacetonates<sup>1a</sup>
作者:Joseph G. Stites、C. N. McCarty、Laurence L. Quill
Effect of f–f interactions on quantum tunnelling of the magnetization: mono- and dinuclear Dy(iii) phthalocyaninato triple-decker single-molecule magnets with the same octacoordination environment
作者:Keiichi Katoh、Rina Asano、Akira Miura、Yoji Horii、Takaumi Morita、Brian K. Breedlove、Masahiro Yamashita
DOI:10.1039/c4dt00042k
日期:——
The single-molecule magnet (SMM) behaviour of dinuclear Ln(III)-Pc triple-decker complexes (Dy(III)âY(III): 1 and Dy(III)âDy(III): 2) with the same octacoordination environment and slow magnetic relaxation behaviour were explained using X-ray crystallography and static and dynamic susceptibility measurements. In particular, interactions among the 4f electrons of dinuclear Dy(III)-Pc triple-decker type SMMs have never been discussed on the basis of the same octacoordination environment. Our results clearly show that the Dy(III) ion sites of 1 and 2 are equivalent, consistent with the crystal structure. 2 Exhibited ferromagnetic interaction between Dy(III) ions. This is clear evidence that the magnetic relaxation mechanism depends heavily on the dipoleâdipole (fâf) interactions between the Dy(III) ions in the dinuclear systems. For both 1 and 2, quantum tunnelling of the magnetization (QTM) was observed. However, the magnetic relaxation time (Ï) for 2 was one order of magnitude greater than that for 1, and single-component magnetic relaxation behaviour was explained. In other words, it is possible to use fâf interactions to increase Ï by one order of magnitude.