The synthesis, structure, magnetic and luminescent properties of a new tetranuclear dysprosium (III) cluster

Chen, Yen-Han; Tsai, Yun-Fan; Lee, Gene-Hsian; Yang, En‐Che

doi:10.1016/j.jssc.2011.10.033

Cited by 15 publications

(8 citation statements)

References 75 publications

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“…Complex 4 is the only member of this family of tetranuclear clusters which shows frequency-dependent out-of-phase χ″ M tails of signals at temperatures below ∼5 K (Figure ), indicative of the slow magnetization relaxation of an SMM with a small energy barrier for magnetization reversal. Such behavior most likely arises from predominant single-ion effects of the individual Dy III centers within 4 . ,,− There were no out-of-phase ac signals down to 1.8 K for the remaining compounds (Figure S2, Supporting Information). Thus, it can be tentatively seen that while 4 shows slow magnetization relaxation the isostructural complex 3 does not.…”

Section: Resultsmentioning

confidence: 99%

“…There have been a large number of Ln 4 complexes reported in the literature, and these possess a wide variety of metal topologies such as linear, rectangles, squares and grids, rhombs and butterflies, cubanes, and dimers of dimers . However, complexes 1 – 7 join only a handful of previous Ln 4 compounds with a similar kind of extended, chain-like topology and an [Ln 4 (μ-OR) 6 ] 6+ core. , …”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Tetranuclear Lanthanide(III) Complexes with a Zigzag Topology from the Use of Pyridine-2,6-dimethanol: Synthetic, Structural, Spectroscopic, Magnetic and Photoluminescence Studies

et al. 2014

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Reaction between Ln(NO3)3·xH2O (x = 5 or 6) and the potentially tridentate (N,O,O) chelating/bridging ligand pyridine-2,6-dimethanol (pdmH2), in the presence of base NEt3, affords a family of isostructural tetranuclear [Ln(III)4(NO3)2(pdmH)6(pdmH2)2](NO3)4 (Ln(III) = Eu(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Yb(III)) complexes with a rare zigzag topology. All complexes contain a [Ln4(μ-OR)6](6+) core with bridging ligation provided by the alkoxido arms of six η(1):η(1):η(2):μ pdmH(-) groups. The Ln(III) ions are eight coordinate with distorted geometries. Direct current magnetic susceptibility studies revealed predominant weak antiferromagnetic exchange interactions between the metal centers, which were quantified in the case of isotropic Gd(III)4 to give J = -0.09(1) cm(-1) and g = 2.00(1). The observation of out-of-phase (χ″M) ac susceptibility signals suggested that the Dy(III)4 analogue might be a molecular nanomagnet. Solid-state photoluminescence studies showed that the Eu(III)4 and Tb(III)4 compounds exhibit intense, sharp, and narrow emission bands in the red and green visible regions, respectively, which arise from the characteristic (5)D0 → (7)FJ and (5)D4 → (7)FJ transitions. The combined results demonstrate the ability of pdmH2 ligand to yield homometallic 4f clusters with interesting magnetic and optical properties.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Tetranuclear Lanthanide(III) Complexes with a Zigzag Topology from the Use of Pyridine-2,6-dimethanol: Synthetic, Structural, Spectroscopic, Magnetic and Photoluminescence Studies

et al. 2014

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“…Besides the two examples, some other linear Dy 4 complexes were also assembled by other groups using the different polydentate ligands, which are presented in Fig. 4.29 [54][55][56]. 4 In 2014, two unique seesaw-like Dy 4 complexes were reported by V. Chandrasekhar [57] and F.-P. Liang [58] groups, respectively.…”

Section: Linear Dy 4 Smmsmentioning

confidence: 97%

Single-Molecule Toroics and Multinuclear Lanthanide Single-Molecule Magnets

Tang

Zhang

2015

Lanthanide Single Molecule Magnets

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In this chapter, we first give a clear definition for single-molecule toroic (SMT) on the basis of the toroidal magnetic moments of ground doublets present in triangular Dy 3 SMMs, which is further exemplified via several typical Dy-based single-molecular magnets (SMMs) showing toroidal magnetic moments. Secondly, we examine the typical polynuclear lanthanide complexes showing SMM behavior, and three main synthetic strategies are given as follows: building block approach, organometallic approach, and multidentate ligand approach. The information extracted from such investigation is expected to enhance our understanding to SMM performances of polynuclear lanthanide complexes and facilitate their future applications.Keywords Single-molecule toroic · Toroidal magnetic moments · Building block · Organometallic approach · Multidentate ligand As mentioned in last two chapters, although the mono-and dinuclear lanthanide complexes have exhibited great achievements in obtaining strongly blocked SMMs due to the strong magnetic anisotropy of lanthanide ions, the limited spin centers in the complexes appear still to prevent the further enhancement of their singlemolecular magnet (SMM) properties due to the limited number of unpaired electrons [1]. Theoretically speaking, the more the spin centers in one metal cluster, the larger spin ground state can be achieved when the ferromagnetic coupling interactions are present in the cluster. Nevertheless, it needs an accurate control for the magnetic anisotropy of each metal center and the magnetic exchange interactions between the metal ions, which seems to be a very challenging task. In particular, it turns to be more difficult for multinuclear lanthanide complexes because the core 4f orbital shielded by the external electrons usually leads to extremely strong magnetic anisotropy of lanthanide ions but poor communication with other metal ions. However, considerable effort of researchers has been devoted to this field, and some groundbreaking results were achieved in this respect. Importantly, the

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“…[3b, 4] Although initially polynuclear complexes containing 3d [5] metali ons were being investigated for SMM behavior, very soon 3d/4fh eterometallicc omplexes [6] and subsequently homometallic 4f [7,9] complexes have been found suitablef or SMM applications.I n particular, complexes containing Dy III ,T b III ,a nd Ho III have been investigated extensively,s ince these ions possess ar elatively high ground state spin along with significant unquenched orbital angular momentum.T hese two parameters are important in generating energy barriers for the reversal of magnetization. Amongt he homometallic lanthanide ion complexes, the tetranuclear family offersc onsiderable structurald iversity and varied structural topologiess uch as linear, [8] distorted cubane, [9] square-grid, [10] tetrahedron, [11] trigonal pyramid, [12] zig-zag, [13] butterfly [14a-l] rhombus, [15] and irregular (Y-shaped, [16] ladder type, [17] sea-saw [18] )a re known. This family also contains some examples such as [Dy 4 K 2 O(OtBu) 12 ] [12] and [Dy 4 (m 3 -OH) 2 (bmh) 2 (msh) 4 Cl 2 ] [14g] (bmh = 1,2-bis(2-hydroxy-3-methoxybenzylidene) hydrazone;m sh = methoxysalicy-laldehyde hydrazone) which showed very high energy barriers for magnetization reversal.…”

Section: Introductionmentioning

confidence: 99%

“…These two parameters are important in generating energy barriers for the reversal of magnetization. Among the homometallic lanthanide ion complexes, the tetranuclear family offers considerable structural diversity and varied structural topologies such as linear, distorted cubane, square‐grid, tetrahedron, trigonal pyramid, zig‐zag, butterfly– rhombus, and irregular (Y‐shaped, ladder type, sea‐saw) are known. This family also contains some examples such as [Dy 4 K 2 O(O t Bu) 12 ] and [Dy 4 (μ 3 ‐OH) 2 (bmh) 2 (msh) 4 Cl 2 ] (bmh=1,2‐bis(2‐hydroxy‐3‐methoxybenzylidene) hydrazone; msh=methoxysalicy‐laldehyde hydrazone) which showed very high energy barriers for magnetization reversal.…”

Section: Introductionmentioning

confidence: 99%

Observation of Slow Relaxation and Single‐Molecule Toroidal Behavior in a Family of Butterfly‐Shaped Ln₄ Complexes

Biswas

Das

Gupta

et al. 2016

Chemistry A European J

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A family of five isostructural butterfly complexes with a tetranuclear [Ln ] core of the general formula [Ln (LH) (μ -η η Piv)(η -Piv)(μ -OH) ]⋅x H O⋅y MeOH⋅z CHCl (1: Ln=Dy , x=2, y=2, z=0; 2: Ln=Tb , x=0, y=0, z=6; 3: Ln=Er , x=2, y=2, z=0; 4: Ln=Ho , x=2, y=2, z=0; 5: Ln=Yb , x=2, y=2, z=0; LH =6-{[bis(2-hydroxyethyl)amino]methyl}-N'-(2-hydroxy-3-methoxybenzylidene)picolinohydrazide; PivH=pivalic acid) was isolated and characterized both structurally and magnetically. Complexes 1-5 were probed by direct and alternating current (dc and ac) magnetic susceptibility measurements and, except for 1, they did not display single-molecule magnetism (SMM) behavior. The ac magnetic susceptibility measurements show frequency-dependent out-of-phase signals with one relaxation process for complex 1 and the estimated effective energy barrier for the relaxation process was found to be 49 K. We have carried out extensive ab initio (CASSCF+RASSI-SO+SINGLE_ANISO+POLY_ANISO) calculations on all the five complexes to gain deeper insights into the nature of magnetic anisotropy and the presence and absence of slow relaxation in these complexes. Our calculations yield three different exchange coupling for these Ln complexes and all the extracted J values are found to be weakly ferro/antiferromagentic in nature (J =+2.35, J =-0.58, and J =-0.29 cm for 1; J =+0.45, J =-0.68, and J =-0.29 cm for 2; J =+0.03, J =-0.98, and J =-0.19 cm for 3; J =+4.15, J =-0.23, and J =-0.54 cm for 4 and J =+0.15, J =-0.28, and J =-1.18 cm for 5). Our calculations reveal the presence of very large mixed toroidal moment in complex 1 and this is essentially due to the specific exchange topology present in this cluster. Our calculations also suggest presence of single-molecule toroics (SMTs) in complex 2. For complexes 3-5 on the other hand, the transverse anisotropy was computed to be large, leading to the absence of slow relaxation of magnetization. As the magnetic field produced by SMTs decays faster than the normal spin moments, the concept of SMTs can be exploited to build qubits in which less interference and dense packing are possible. Our systematic study on these series of Ln complexes suggest how the ligand design can help to bring forth such SMT characteristics in lanthanide complexes.

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The synthesis, structure, magnetic and luminescent properties of a new tetranuclear dysprosium (III) cluster

Cited by 15 publications

References 75 publications

Tetranuclear Lanthanide(III) Complexes with a Zigzag Topology from the Use of Pyridine-2,6-dimethanol: Synthetic, Structural, Spectroscopic, Magnetic and Photoluminescence Studies

Tetranuclear Lanthanide(III) Complexes with a Zigzag Topology from the Use of Pyridine-2,6-dimethanol: Synthetic, Structural, Spectroscopic, Magnetic and Photoluminescence Studies

Single-Molecule Toroics and Multinuclear Lanthanide Single-Molecule Magnets

Observation of Slow Relaxation and Single‐Molecule Toroidal Behavior in a Family of Butterfly‐Shaped Ln₄ Complexes

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The synthesis, structure, magnetic and luminescent properties of a new tetranuclear dysprosium (III) cluster

Cited by 15 publications

References 75 publications

Tetranuclear Lanthanide(III) Complexes with a Zigzag Topology from the Use of Pyridine-2,6-dimethanol: Synthetic, Structural, Spectroscopic, Magnetic and Photoluminescence Studies

Tetranuclear Lanthanide(III) Complexes with a Zigzag Topology from the Use of Pyridine-2,6-dimethanol: Synthetic, Structural, Spectroscopic, Magnetic and Photoluminescence Studies

Single-Molecule Toroics and Multinuclear Lanthanide Single-Molecule Magnets

Observation of Slow Relaxation and Single‐Molecule Toroidal Behavior in a Family of Butterfly‐Shaped Ln4 Complexes

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Observation of Slow Relaxation and Single‐Molecule Toroidal Behavior in a Family of Butterfly‐Shaped Ln₄ Complexes