A Molecular-Based Magnet with a Fully Interlocked Three-Dimensional Structure

Stumpf, Humberto O.; Yu, Peng; Kahn, Olivier; Ouahab, Lahcène; Grandjean, Daniel

doi:10.1126/science.261.5120.447

Cited by 465 publications

(176 citation statements)

References 25 publications

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“…The result was polycatenated 2D networks [63] {(Me-rad) 2 Mn 2 [Cu(opba)l 3 (DMSO) 2 ]·2H 2 O} n (2D-MnCuopba-a). [64] The polycatenated networks are nearly perpendicular as depicted in Figure 15.…”

Section: D Coordination Polymersmentioning

confidence: 74%

Design of Magnetic Coordination Polymers Built from Polyoxalamide Ligands: A Thirty Year Story

et al. 2018

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Abstract:The aim of this review is to pay tribute to the legacy of O. Kahn. Kahn's credo was to synthesize magnetic compounds with predictable structure and magnetic properties. This is illustrated herein with results obtained by Kahn's group during his Orsay period thirty years ago, but also on the basis of our recent results on the synthesis of coordination polymers with oxamate ligands. The first part of this review is devoted to a short description of the necessary knowledge in physics and theoretical chemistry that Kahn and his group have used to select oxamate ligands, the complex-as-ligand strategy and the synthesis of heterobimetallic systems. Then, we describe the strategies we have later used to obtain the desired target compounds. The use of complexes as building-blocks, associated to a control of the metal ions chirality and stoichiometry, allowed us to obtain coordination polymers with predictable dimensionality. For the synthesis of single-chain magnets (SCMs) we show IncipitFor this thematic issue dedicated to the attractive legacy of Olivier Kahn, we decided to write this paper on magnetic coordination polymers built from polyoxalamide ligands. Some of the authors of this paper were part of the exciting adventure at the time of the creation of the Kahn's group at the University of Paris-Sud. Kahn's credo was to synthesize magnetic compounds with predictable structure and magnetic properties and in order to achieve this goal one needs some backgrounds in physics, theory and synthetic chemistry. We have therefore tried that the ligand chemical flexibility makes the isolation of the chains in the solid and the occurence of slow magnetic relaxation possible. For 1D and 2D molecule-based magnets (MBMs), the magnetic ordering strongly depends on the interchain or interplane interactions, which are difficult to control. Again the flexibility of the oxamate ligands allowed their strengthening in the solid sate, yielding MBMs with critical temperatures up to 30 K. We will also present our results on 3D coordination polymers, particularly on the porous magnets displaying large octagonal channels. This family of porous MBMs possess outstanding chemical properties, such as post-synthetic transformation in the solid state. Finally, we will also show that oxamate ligands allows the design of multifunctional materials, as in the case of the first chiral SCM. Overall, the results presented in this review show the impressive potential the oxamate ligands have for the design of coordination polymers.throughout this contribution to describe the historical process and the approach of the group's behind the choice of oxamate and oxamidate ligands to synthesize heterometallic coordination polymers.

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Section: D Coordination Polymersmentioning

confidence: 74%

Design of Magnetic Coordination Polymers Built from Polyoxalamide Ligands: A Thirty Year Story

et al. 2018

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“…For instance, the diethylester Et 2 H 2 -opba proligand, with opba = ortho-phenylenebis (oxamato), that our group has thoroughly employed, can be used to form a precursor or ligand such as [Cu(opba)] 2-, suitable to bind to a variety of metal ions. The strategy to use [Cu(opba)] 2-as building block of molecule-based magnets was first proposed 7 and effectively described 8 in 1993. Since that date, there was a concern with the design and synthesis of new molecular edifices, aiming to investigate their structure-properties correlations.…”

Section: Introductionmentioning

confidence: 99%

A new molecular magnetic semiconductor based on tetrathiafulvalene (ttf) and oxamato ligand (opba): [ttf]2[Cu(opba)]·H2O

Dias¹,

Stumpf²,

Mambrini³

et al. 2010

J. Braz. Chem. Soc.

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. As propriedades magnéticas (dc) mostram um valor do produto c M T na temperatura ambiente próximo ao esperado para três spins S = ½ desacoplados e um valor de 0.13 emu K mol -1 a baixas temperaturas (4 K). A curva do produto c M T versus T foi ajustada e o melhor modelo consiste de um termo para o dímero (ttf •+ ) 2 (Bleaney-Bowers, resultando em J 2 = -186 cm ).An oxamato-based compound of formula [ttf] 2 [Cu(opba)]·H 2 O, with ttf = tetrathiafulvalene and opba = ortho-phenylenebis(oxamato), has been prepared and characterized. The complex was obtained by metathesis from (ttf) 3 (BF 4 ) 2 and (Bu 4 N) 2 [Cu(opba)] in acetonitrile at room temperature. The UV-Vis-NIR spectrum reveals the presence of the radical cation in two forms, (ttf Keywords: tetrathiafulvalene, molecular magnetism, semiconductor, oxamato ligand, molecular spintronics IntroductionIn the last few decades, the search for a molecular equivalent of a given material has increased, owed to the possibility to incorporate a new property through organic or coordination compounds maintaining the features of the original system. In the area of electronic materials, for example, molecular conductors constitute a theme of large appeal, where ttf (tetrathiafulvalene, 2,2'-bi-1,3-dithiole) and its derivatives are by far the most investigated. Ttf is a π-electron donor capable to form radical [ttf 2 In Dias et al. 1275 Vol. 21, No. 7, 2010 1973, the first 1D metal [ttf-tcnq] (with tcnq = tetra-cyanop-quinodimethane) was described.3 Its structure consists of stacks of either the tcnq or ttf planar molecules and there is a partial electron transfer from the donor to the acceptor forming the charge-transfer salt [ttf] δ+ [tcnq] containing organic radicals and paramagnetic coordination compounds are found in the literature. The stacking of multilayers is the topological feature of the devices that already use the GMR or MTJ technologies with magnetic control of the flow of spin-polarized electrons. Indeed, a molecular construction of each thin layer with specific properties, promoting tailored interlayer interactions or maintaining isolation through organic or inorganic spacers represents a significant challenge to synthetic chemists.Our group has worked with several planar building blocks and organic radicals that show the capability to form 2D networks, negatively or positively charged, which are candidates to contribute to the development of a molecular branch of spintronics. Recently, a magnetic molecular semiconductor based on a dithiolene ligand derivative and the nitronyl nitroxide radical cation was presented. 24Herein we report the synthesis and properties of the first molecular semiconductor with the tetrathiafulvalene cation and a paramagnetic oxamato-based complex of formula Experimental Physical measurementsInfrared spectra were obtained by using a Fourier transform infrared spectrometer Galaxy 3030 model (Mattson Instrument) with DTGS (deuterated triglycine sulphate) detector on KBr pellets. The UV-Vis-NIR absorption spectra were mea...

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“…We succeeded in designing two-dimensional magnets of formula [ 12 where Me-Rad + is a nitronyl nitroxide radical cation (see Figure 1b). This compound, a magnet with T c of 22 K, presents a rare interlocked structure.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Properties of New Molecule-Based Magnets Containing Mn(II), Cu(II) and Nitronyl Nitroxide Radical Cation

Vaz

Knobel

Speziali

et al. 2002

J. Braz. Chem. Soc.

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Neste trabalho, descrevemos a obtenção de dois novos compostos de cobre(II), ou precursores, (Pr-Rad) 2 3DMSO.6H 2 O (4), respectivamente. As propriedades magnéticas dos precursores 1 e 2 mostram a presença de interações ferromagnéticas entre os radicais cátions e o cobre (II), na faixa de temperatura entre 20 e 300 K. Os magnetos moleculares 3 e 4 exibem magnetização espontânea com temperatura crítica, T c , de 23 K e 24 K, respectivamente.In this work, we describe the synthesis of two new copper(II) compounds, (Pr-Rad) 2 [Cu(opba)].H 2 O (1) and (Bu-Rad) 2 [Cu(opba)].2H 2 O (2) where opba stands for orthophenylenebis(oxamato) and R-Rad + are nitronyl nitroxide radical cations. From 1 and 2, two new molecule-based magnets [Pr-Rad] 2 [Mn 2 {Cu(opba)} 3 ].3.3DMSO.5H 2 O (3) and [Bu-Rad] 2 [Mn 2 {Cu(opba)} 3 ].3DMSO.6H 2 O (4) were obtained, respectively. The magnetic properties of precursors 1 and 2 show the presence of ferromagnetic interaction between the radical cations with copper(II), in the temperature range of 20-300 K. The magnets 3 and 4 exhibit spontaneous magnetization at critical temperatures, T c , of 23 K and 24 K, respectively. Keywords: supramolecular chemistry, molecule-based magnets, molecular materials, catenanes, ferrimagnetism IntroductionAs evidenced by the remarkable increase in publications on the topic, the field of molecule-based magnetism is flourishing. However, the critical temperature of the molecule-based magnets remains low and up to now there have not been compounds of this type used for any technological application. Four molecule-based magnets have been reported to remain magnetically ordered near room temperature.1-3 One of them decomposes at 350 K, and the other three demagnetize near 315 K. The crystal structures of these compounds have not all been determined.One of the outstanding features of molecule-based materials is that the magnetic properties may be transformed by quite small and subtle modifications in the molecular chemistry. Variations in the organic molecules may lead to modifications in the magnetism of the material. Sometimes the molecular fragments only serve as spacers and are not involved directly in the interaction between neighboring atoms. 4 In other cases, the organic part, although not possessing magnetic moment or not being responsible for the transmission of the interaction is essential to the exchange process. 5 In the last few years, numerous magnetic molecular units carrying spin and able to establish 3 ], (pbaOH = 2-hydroxy-1,3-propylenebis(oxamato)) with T c = 4.6 K.In the beginning of the nineties, we initiated a research in the direction to increase the dimensionality of the compounds using a more 'organic' building block: [Cu(opba)] 2-where opba stands for ortho-phenylenebis(oxamato) (see Figure 1a). We succeeded in designing two-dimensional magnets of formula [cat] Figure 1b). This compound, a magnet with T c of 22 K, presents a rare interlocked structure. Moreover, by the time of the description of this compound, no molecular magnet...

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A Molecular-Based Magnet with a Fully Interlocked Three-Dimensional Structure

Cited by 465 publications

References 25 publications

Design of Magnetic Coordination Polymers Built from Polyoxalamide Ligands: A Thirty Year Story

Design of Magnetic Coordination Polymers Built from Polyoxalamide Ligands: A Thirty Year Story

A new molecular magnetic semiconductor based on tetrathiafulvalene (ttf) and oxamato ligand (opba): [ttf]2[Cu(opba)]·H2O

Synthesis and Properties of New Molecule-Based Magnets Containing Mn(II), Cu(II) and Nitronyl Nitroxide Radical Cation

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