Assembly of Lanthanide(III) Cubanes and Dimers with Single-Molecule Magnetism and Photoluminescence

Wong, Ho-Yin; Chan, Wesley Ting Kwok; Law, Ga Lai

doi:10.1021/acs.inorgchem.8b00505

Cited by 39 publications

(16 citation statements)

References 59 publications

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“…The plot of ln(τ/s) versus T –1 (Figure c) for 2 derived from the related magnetic data under zero field was simulated according to eq by omitting the last two terms, giving U eff / k B = 40 K, τ 0 = 1.68 × 10 –6 s, and C = 372 s –1 K –2.12 , and n = 2.12. The U eff / k B for 2 is higher than those (<10 K) for the reported complexes with similar skeletons. − These results might reveal that there are multiple relaxation pathways involved in the relaxation processes in both 1 and 2 . ,, …”

Section: Resultsmentioning

confidence: 80%

Two Dy(III) Single-Molecule Magnets with Their Performance Tuned by Schiff Base Ligands

Chen

et al. 2019

Inorg. Chem.

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To develop new lanthanide single-molecule m a g n e t s ( S M M s ) , t w o n e w c o m p l e x e s o f [Dy 2 (MeOH) 2 (HL 1 ) 2 (NO 3 ) 2 ]•2MeOH (1) and [Dy 6(2) were obtained by reacting Dy(NO) 3 •6H 2 O with 3-amino-1,2-propanediol in the presence of 2-hydroxynaphthaldehyde for 1 and by reacting DyCl 3 •6H 2 O with 1,1-di-(hydroxymethyl)ethylamine in the presence of 2-hydroxynaphthaldehyde for 2, respectively, in which the Schiff base ligands of 3-(((2-hydroxynaphthaen-1-yl)methylene)amino)propane-1,2-diol (H 3 L 1 ) and 2-(β-naphthalideneamino)-2-(hydroxylmethyl)-1-propanol (H 3 L 2 ) were in situ formed. The two Dy(III) ions in 1 are linked by two O alkoxy atoms of two (HL 1 ) 2− ligands to build a dinuclear skeleton. Complex 2 presents a nearly planar hexanuclear skeleton constructed from four edge-shared triangular Dy 3 units with the two peripheral Dy 3 units consolidated by two μ 3 -O bridges and the two central Dy 3 units consolidated by one μ 3 -O bridge. Obviously, they exhibit a different topological arrangement resulting from the linkage of the Schiff base ligands. Both of them are typical SMMs under zero dc fields, with a U eff /k B value of 34 K for 1 and 40 K for 2, respectively. Multiple processes are involved in the relaxation processes of 1 and 2. The different SMM performances of the two titled complexes reveal a tuning effect of Schiff base ligands through tuning the coordination environments and topological arrangements of dysprosium(III) ions, which is supported by the theoretical calculations.

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Section: Resultsmentioning

confidence: 80%

Two Dy(III) Single-Molecule Magnets with Their Performance Tuned by Schiff Base Ligands

Chen

et al. 2019

Inorg. Chem.

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“…Moreover, the spin-reversal barrier (U eff ) is in line with the one approximated using an Arrhenius plot (36.53(5) K; Supplementary Figure 3). This value represents the third highest energy barrier at zero field within the class of Ln 4 cubanes (Supplementary Table 4) [45][46][47] . Thus, we demonstrate that the incorporation of open-shell ligands can improve the magnetic performance of Ln III -based cluster-aggregates, however, at the same time, we maintain that such a feature cannot exclusively be relied on in order to optimize the anisotropy barrier.…”

Section: Resultsmentioning

confidence: 99%

A tunable lanthanide cubane platform incorporating air-stable radical ligands for enhanced magnetic communication

et al. 2018

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The unique properties of polynuclear cluster-aggregates have long been staples in the molecular magnetism community. The initial success observed in high nuclearity transition metal complexes for generating exciting magnetic behaviors however, has not yet fully been extended to lanthanide-based clusters. This is in part due to the challenges related to promoting non-negligible magnetic interactions between two lanthanide ions. One promising route towards improving magnetic communication involves the incorporation of radical species. Here, we describe the preparation of tetranuclear [Dy 4 (μ 3-OH) 4 ] 8+ core structures that allow the incorporation of air-stable radical ligands. This combination paves the way for magnetically relevant lanthanide cubane cluster-aggregates capable of strong magnetic communication and improved spin-reversal barriers. Moreover, we show that the addition of electron donating groups lead to non-negligible antiferromagnetic coupling between the Dy III centers and the BPyTz •− ligands, while also simultaneously improving the slow magnetic relaxation dynamics in the absence of an applied field.

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“…Polynuclear Ln 3+ clusters attract increasing attention, as a result of their intriguing geometrical features and interesting properties related to magnetic, quantum computing and luminescent applications. The reported Ln 3+ clusters mainly include trinuclear (Ln 3 , Ln = Gd, Tb, Dy, Ho), [16,17] tetranuclear (Ln 4 , Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb), [18][19][20][21][22][23][24][25][26][27] pentanuclear (Ln 5 , Ln = Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb), [25] hexanuclear (Ln 6 , Ln = Pr, Ce, Eu, Gd, Tb, Dy, Er and Y), [27][28][29][30] octagon (Ln 8 , Ln = Gd, Tb, Dy, Ho), [31] nine-nuclear (Ln 9 , Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho), [32][33][34] eleven-nuclear (Ln 11 , Ln = Gd, Tb, Dy), [35] dodecanuclear (Ln 12 , Ln = Eu, Gd, Tb, Dy), [32,[36][37][38] hexadecanuclear (Ln 16 , Ln = Gd, Dy) clusters. [39] The number of Ln nuclei in Ln 3+ clusters was often controlled by the preferred coordination geometry of ligands [32] and the reaction environments.…”

Section: Cluster Chemistry Of Group 3 and 4 Metalsmentioning

confidence: 99%

Metal–Organic Frameworks Based on Group 3 and 4 Metals

et al. 2020

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Metal-organic frameworks (MOFs), a class of porous crystalline framework materials, are linked by strong bonds between inorganic and organic building blocks. [1-3] In the past two decades, MOFs have rapidly grown as a star material due to their exceptional performance in areas such as storage, separation and catalysis. [4] The outstanding performance of MOFs in applications benefits from their intrinsically porous structures and highly tunable pore environment. [5-7] The creation and modification of pore space with optimized size, functionality and diversity can be precisely tuned at the molecular level by rationally designing building blocks and synthetic procedures. [8,9] The diversity of MOFs can be enriched by expanding the library of organic linkers with varying lengths, geometries, and functional groups. [10] Additionally, very diverse metal cations are applied to MOF synthesis, ranging from monovalent (Ag + , Cu + , etc.), divalent (Mg 2+ , Fe 2+ , Co 2+ , Ni 2+ , etc.), trivalent (Al 3+ , Sc 3+ , V 3+ , Cr 3+ , etc.), to tetravalent (Ti 4+ , Zr 4+ , Hf 4+ , etc.) cations. [11] In this review, we mainly focus on MOFs with group 3 and 4 metals, including Y, lanthanides (Ln, from La to Lu), actinides (An, from Ac to Lr), Ti, and Zr (Figure 1). Group 3 metal cations are generally found in the oxidation state of +3 in the MOF structures, while group 4 metal cations mainly exist in the oxidation state of +4, leading to the formation of much stronger coordination bonds with carboxylates. [12] Therefore, group 4 metal-based MOFs (M IV-MOFs) generally have enhanced stability compared with MOFs constructed from metals of group 3 and other groups. This series of MOFs stands out because the involved metals can generally coordinate with carboxylates to form frameworks with strong coordination bonds, according to the Pearson's hard/soft acid/base principle, where group 3 and 4 metal cations are regarded as hard acids while carboxylate ligands are hard bases. [11] One remarkable feature of MOFs with group 3 and 4 metals is that they generally can form phases containing M 6 O 8 (M = Y, Ln, An, Zr and Hf) clusters, regardless of their atomic numbers, charges and radius. This series of M 6-based MOFs is best represented by UiO series such as UiO-66 with fcu topology. [13] Under different synthetic conditions, UiO-66(M, M = An, Zr and Hf) constructed from [M 6 (μ 3-O) 4 (μ 3-OH) 4 ] clusters and linear carboxylates can be obtained, while UiO-66(M, M = Y, Ln) is assembled from Metal-organic frameworks (MOFs) based on group 3 and 4 metals are considered as the most promising MOFs for varying practical applications including water adsorption, carbon conversion, and biomedical applications. The relatively strong coordination bonds and versatile coordination modes within these MOFs endow the framework with high chemical stability, diverse structures and topologies, and interesting properties and functions. Herein, the significant progress made on this series of MOFs since 2018 is summarized and an update on the current status an...

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Assembly of Lanthanide(III) Cubanes and Dimers with Single-Molecule Magnetism and Photoluminescence

Cited by 39 publications

References 59 publications

Two Dy(III) Single-Molecule Magnets with Their Performance Tuned by Schiff Base Ligands

Two Dy(III) Single-Molecule Magnets with Their Performance Tuned by Schiff Base Ligands

A tunable lanthanide cubane platform incorporating air-stable radical ligands for enhanced magnetic communication

Metal–Organic Frameworks Based on Group 3 and 4 Metals

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