Bifunctional Ligand Approach for Constructing 3d−4f Heterometallic Clusters

Wu, Gang; Hewitt, Ian J.; Mameri, Samir; Lan, Yanhua; Clérac, Rodolphe; Anson, Christopher E.; Qiu, Shilun; Powell, Annie K.

doi:10.1021/ic070296a

Cited by 83 publications

(46 citation statements)

References 32 publications

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“…For example, combining o-vanillin and tris (hydroxymethyl) aminomethane to give the ligand (H 4 L, Scheme 1) provides a system which captures two Gd III and five Cu II ions in [Gd 2 Cu 5 (OH) 4 (Br) 2 (H 2 L) 2 (H 3 L) 2 (NO 3 ) 2 (OH 2 ) 4 ] 2+ (see Fig. 4) [51]. While this ligand had been previously used to prepare homometallic clusters [52], it seemed reasonable to hope that the oxygen-donor-rich tripodal tris(hydroxymethyl) aminoethane derived group would capture the oxophilic lanthanide, whereas the Cu II ions would be coordinated by both the imine nitrogen and oxygen donors.…”

Section: Compartmentalized Ligandsmentioning

confidence: 99%

Strategies towards single molecule magnets based on lanthanide ions

Sessoli

Powell

2009

Coordination Chemistry Reviews

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707

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Section: Compartmentalized Ligandsmentioning

confidence: 99%

Strategies towards single molecule magnets based on lanthanide ions

Sessoli

Powell

2009

Coordination Chemistry Reviews

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1,427

707

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“…The fact that this core motif is a decorated version of that in the [Cu5Gd2] 13 compound (3,6M7-2) is easily verified by graphical screening. Scrutinizing the molecular formula, the synthetic recipe and the organic ligands used to build these entities, it is clear that the presence of the CH3 group in complex 1 in place of the OH group in the Cu5Gd2 compound 13 favors the addition of two Cu2 units resulting in the formation of the undecanuclear species as a result of deletion of H-bonding with adjacent or solvent molecules. Other modifications to the ligand offer further possibilities for structural tuning.…”

Section: 17mentioning

confidence: 99%

“…The central core ( Figure S1) is essentially the same as that of the previously reported Cu5Gd2 cluster. 13 The {Cu5Dy2} unit is bridged by four 3-hydrox- (5) has a square-planar ligand environment ( Figure S2). The Dy III ions are nine-coordinate.…”

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confidence: 99%

An Undecanuclear Ferrimagnetic Cu₉Dy₂ Single Molecule Magnet Achieved through Ligand Fine-Tuning

et al. 2016

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ABSTRACT:We describe the concept of increasing the nuclearity of a previously reported high-spin Cu5Gd2 core using a "fine tuning" ligand approach. Thus two Cu9Ln2 coordination clusters, with Ln = Dy (1), Gd(2) were synthesized with the Gd compound having a ground spin state of 17/2 and the Dy analogue showing SMM behavior in zero field.In the burgeoning area of 3d-4f coordination clusters (CCs) for those showing Single Molecule Magnet (SMM) behavior it is becoming increasingly clear that the correct blend of 3d and 4f ions in conjunction with the resulting topology of the clusters are important factors governing this behavior. 1 For 3d/4f SMMs the magnetic behavior can show two slow relaxation regimes corresponding to the single 4f ion and to the exchange coupled 3d/4f processes as evidenced within the frequency window of routine ac susceptibility studies where, in contrast to 4f single ion systems, 2,3 these can obey an Arrhenius law with two linear dependences corresponding to the two relaxation pathways, as was shown for a Co II 2Dy III 2 system. 4 Generally such systems can be treated within the coupled 3d/4f regime as giant spin systems. As such they show relatively low effective energy barriers to spin inversion (Ueff) when compared with the very high barriers often predicted for single 4f ion systems. 5 However, this is compensated by a suppression of quantum tunneling effects, which are particularly complicated and prevalent for 4f single ions. Thus, for high spin 3d/4f systems it can be possible to observe and analyze the relaxation data within the usual frequency window of ac susceptibility measurements in zero applied dc field for both the single ion and exchange coupled cases. 4 CCs combining highly anisotropic 4f ions such as Dy III with the quantum spin Cu II d 9 ion 6 have received less attention than other combinations, but amongst the relatively few examples of such SMMs, 7 the even rarer cases with high nuclearities above 10 [8][9][10][11][12]7 have the advantage that the molecules possessing high spins and are well-separated within the crystal structure. Although these systems can show slow relaxation of the magnetization, as evidenced by frequency-dependent ac-susceptibilities, the maxima of the characteristic out-of-phase signals are often shifted beyond the available frequency window. 9,10 Only rarely the SMM behaviour can be proved solely by ac measurments. 7 We show here how a ligand engineering approach applied to a system with a favorable core spin-topology leads to Cu II /Dy III SMM. We took our previously reported Cu5Gd2 CC, for which we were unable to isolate the Dy III analogue, as a starting point. This has a high S = 17/2 ground spin state and is synthesized using the Schiffbase ligand H4L1 (Figure 3), 13 based on o-vanillin and tris(hydroxymethyl)aminoenthane (tris). Given that one or even two hydroxyl groups of the tripodal alcohol unit may not be involved in coordination, but form inter-and intramolecular hydrogen-bonds to solvent molecules, neighbouring clusters or internal O...

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“…Recently, to gain an insight into the Cu···Gd exchange interaction in polynuclear compounds and to understand how the magnetic exchange interactions therein contribute to –Δ S m , Rajaraman et al selected two structurally related {

{Cu}_{5}^{II}

Gd n }, 110 ,89a and 125 ,98 clusters and investigated the origin of the large MCE using DFT methods 97. The calculated maximum –Δ S m value is 19.3 J kg −1 K −1 for 125 at 3.0 K for an applied field of 90 kOe.…”

Section: Recent Advances In Coordination‐cluster‐based Molecular Magnmentioning

confidence: 99%

Coordination‐Cluster‐Based Molecular Magnetic Refrigerants

Zhang

Cheng

2016

The Chemical Record

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Coordination polymers serving as molecular magnetic refrigerants have been attracting great interest. In particular, coordination cluster compounds that demonstrate their apparent advantages on cryogenic magnetic refrigerants have attracted more attention in the last five years. Herein, we mainly focus on depicting aspects of syntheses, structures, and magnetothermal properties of coordination clusters that serve as magnetic refrigerants on account of the magnetocaloric effect. The documented molecular magnetic refrigerants are classified into two primary categories according to the types of metal centers, namely, homo- and heterometallic clusters. Every section is further divided into several subgroups based on the metal nuclearity and their dimensionalities, including discrete molecular clusters and those with extended structures constructed from molecular clusters. The objective is to present a rough overview of recent progress in coordination-cluster-based molecular magnetic refrigerants and provide a tutorial for researchers who are interested in the field.

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Bifunctional Ligand Approach for Constructing 3d−4f Heterometallic Clusters

Abstract: Using a predesigned Schiff-base tripodal ligand, a heptanuclear CuII-GdIII cluster with a spin ground state of S=17/2 has been synthesized.

Cited by 83 publications

References 32 publications

Strategies towards single molecule magnets based on lanthanide ions

Strategies towards single molecule magnets based on lanthanide ions

An Undecanuclear Ferrimagnetic Cu₉Dy₂ Single Molecule Magnet Achieved through Ligand Fine-Tuning

Coordination‐Cluster‐Based Molecular Magnetic Refrigerants

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Bifunctional Ligand Approach for Constructing 3d−4f Heterometallic Clusters

Abstract: Using a predesigned Schiff-base tripodal ligand, a heptanuclear CuII-GdIII cluster with a spin ground state of S=17/2 has been synthesized.

Cited by 83 publications

References 32 publications

Strategies towards single molecule magnets based on lanthanide ions

Strategies towards single molecule magnets based on lanthanide ions

An Undecanuclear Ferrimagnetic Cu9Dy2 Single Molecule Magnet Achieved through Ligand Fine-Tuning

Coordination‐Cluster‐Based Molecular Magnetic Refrigerants

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Product

Resources

About

An Undecanuclear Ferrimagnetic Cu₉Dy₂ Single Molecule Magnet Achieved through Ligand Fine-Tuning