Dimensionality of manganese(II)-copper(II) bimetallic compounds and design of molecular-based magnets

Stumpf, Humberto O.; Yu, Peng; Kahn, Olivier; Sletten, Jorunn; Renard, Jean

doi:10.1021/ja00068a034

Cited by 224 publications

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“…2 All reagents were used as purchased without further purification. Elemental analyses (C, H, N) were performed on a 2400 CHN-Perkin Elmer instrument.…”

Section: Methodsmentioning

confidence: 99%

“…Data from elemental analysis, IR and Mössbauer spectroscopies and magnetic measurements indicate that this precursor is composed of a mixture of trans (83%) and cis (17%) isomers. The χ M T value at 298K (2.1 emu K mol 2 ] + show that both isomers have spin S = 1/2 in the ground state and S = 3/2 for the trans and S = 5/2 for the cis in the first excited state. The combination of these results leads to χ M T values of 0.375 and 2.3 emu K mol…”

Section: Synthesis and Density Functional Calculations Of The New Molmentioning

confidence: 97%

“…O valor de χ M T a 298 K (2,1 emu K mol -1 ) corresponde ao Fe III com estado de spin (S) entre 3/2 e 5/2. Cálculos teóricos (PBE/DZVP2) de trans-e cis-[Fe(H 2 opba-i)(dmso) 2 ] + mostram que ambos os isômeros têm spin S = 1/2 no estado fundamental e S = 3/2 para o trans e S = 5/2 para o cis no primeiro estado excitado. A combinação destes resultados leva a valores de χ M T de 0,375 emu K mol -1 e 2,3 emu K mol -1 a baixas e altas temperaturas, respectivamente, os quais são concordantes com os dados experimentais para 1.…”

Section: Synthesis and Density Functional Calculations Of The New Molunclassified

“…1 In 1993, the new precursor [Bu 4 N] 2 [Cu(opba)], opba = ortho-phenylenebis(oxamato), was synthesized and largely used as a building block, due to its high solubility in common organic solvents. 2 The majority of the work done with oxamato-based building blocks is with Cu II , most probably due to the stability of the compounds with this metal ion. Another reason for employing this metal ion resides on the ferrimagnetic strategy, which consists in the use of two metal ions with large difference in spin states and with 1535Souza et al Vol.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and density functional calculations of the new molecule-based magnet precursor [Fe(H2opba-i)(dmso)2]Cl

Souza¹,

Konzen²,

Ardisson³

et al. 2006

J. Braz. Chem. Soc.

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Um precursor inédito de sistemas magnéticos moleculares, [Fe(H 2 opba-i)(dmso) 2 ]Cl (1), onde opba = orto-fenilenobis(oxamato) na forma tautomérica iminoálcool, foi obtido como produto da reação entre H 4 opba e FeCl 3 . Os dados de análise elementar, espectroscopias de absorção no infravermelho e Mössbauer e medidas magnéticas indicam que este precursor é constituído por uma mistura de isômeros trans (83%) e cis (17%). O valor de χ M T a 298 K (2,1 emu K mol -1 ) corresponde ao Fe III com estado de spin (S) entre 3/2 e 5/2. Cálculos teóricos (PBE/DZVP2) de trans-e cis- [Fe(H 2 opba-i)(dmso) 2 ]+ mostram que ambos os isômeros têm spin S = 1/2 no estado fundamental e S = 3/2 para o trans e S = 5/2 para o cis no primeiro estado excitado. A combinação destes resultados leva a valores de χ M T de 0,375 emu K mol -1 e 2,3 emu K mol -1 a baixas e altas temperaturas, respectivamente, os quais são concordantes com os dados experimentais para 1.A new precursor of molecule-based magnetic systems, [Fe(H 2 opba-i)(dmso) 2 ]Cl (1), with opba = ortho-phenylenebis(oxamato) in an iminoalcohol tautomeric form, was obtained as a product from the reaction between H 4 opba and FeCl 3 . Data from elemental analysis, IR and Mössbauer spectroscopies and magnetic measurements indicate that this precursor is composed of a mixture of trans (83%) and cis (17%) isomers. The χ M T value at 298K (2.1 emu K mol -1 ) corresponds to Fe III with spin state (S) between 3/2 and 5/2. Theoretical calculations (PBE/ DZVP2) of trans-and cis-[Fe(H 2 opba-i)(dmso) 2 ] + show that both isomers have spin S = 1/2 in the ground state and S = 3/2 for the trans and S = 5/2 for the cis in the first excited state. The combination of these results leads to χ M T values of 0.375 and 2.3 emu K mol -1 , at low and high temperature respectively, which are in accordance with the experimental data for 1. Keywords: molecule-based magnet, oxamate, iron(III), PBE/DZVP theoretical calculations, cis/trans isomerism IntroductionThe oxamato-based ligands have an important role in molecular magnetism. In the seventies, the proligand 1,3-propylenebis(oxamato), pba, was synthesized, and some years later it was used in the preparation of molecule-based magnets.1 In 1993, the new precursor [Bu 4 N] 2 [Cu(opba)], opba = ortho-phenylenebis(oxamato), was synthesized and largely used as a building block, due to its high solubility in common organic solvents. 2The majority of the work done with oxamato-based building blocks is with Cu II , most probably due to the stability of the compounds with this metal ion. Another reason for employing this metal ion resides on the ferrimagnetic strategy, which consists in the use of two metal ions with large difference in spin states and with 1535 Souza et al. Vol. 17, No. 8, 2006 antiferromagnetic coupling. In this approach, copper complexes can bridge several metal ions resulting in extended molecular systems (chains, two-and threedimensional networks) and clusters. ExperimentalThe proligand H 4 opba was prepared using an adaptation of a ...

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“…2 All reagents were used as purchased without further purification. Elemental analyses (C, H, N) were performed on a 2400 CHN-Perkin Elmer instrument.…”

Section: Methodsmentioning

confidence: 99%

Section: Synthesis and Density Functional Calculations Of The New Molmentioning

confidence: 97%

Section: Synthesis and Density Functional Calculations Of The New Molunclassified

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Synthesis and density functional calculations of the new molecule-based magnet precursor [Fe(H2opba-i)(dmso)2]Cl

Souza¹,

Konzen²,

Ardisson³

et al. 2006

J. Braz. Chem. Soc.

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“…Syntheses: The radical 2-(pyridine-4-yl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, abbreviated as rad, [36,37,44] the ligand opba, and the tetrabutylammonium salt of the Cu 2 precursor, [(NBu 4 ) 2 Cu(opba)], [11,37] were prepared as already described. À4 mol) in DMSO (6 mL).…”

Section: Methodsmentioning

confidence: 99%

Soft and Hard Molecule-Based Magnets of Formula [(Etrad)2M2{Cu(opba)}3]⋅S [Etrad+=Radical Cation, MII=MnII or CoII, opba=Ortho-phenylenebis(oxamato), S=Solvent Molecules], with a Fully Interlocked Structure

et al. 1999

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The goal of this work was to explore the chemistry and the physics of a family of molecule-based magnets containing three spin carriers, with a fully interlocked structure. The main emphasis was on the coercivity of these magnets, which confers a memory effect on the materials. stands for the radical cation 2-(1-ethylpyridinium-4-yl)-4,4,5,5-tetramethylimidazolin-1-oxyl-3-oxide, and opba stands for ortho-phenylenebis-(oxamato). The crystal structures of the three compounds have been determined. The structure of 1 consists of planar Cu(opba) units with one of the radical cations weakly bound to the Cu 2 ion, the other radical cation being rather isolated. Compounds 2 and 3 are isomorphous. Their structure consists of two interpenetrating graphitelike networks with edge-sharing hexagons. The magnetic properties of the three compounds have been investigated in detail. For compounds 2 and 3 the temperature dependences of the direct current (dc) and alternating current (ac) magnetic responses have been measured along with the field dependence of the magnetization. Both compounds exhibit a long-range magnetic ordering with a spontaneous magnetization. The critical temperatures are 22.8 K and 37 K for 2 and 3, respectively. While 2 is a soft magnet, 3 has been found to be a very hard magnet, with a coercive field depending on the particle size. This coercive field may reach 24 kOe at 6 K for a sample consisting of very small crystals. Mixed materials with the abbreviated formula [Etrad 2 Mn 2À2x Co 2x Cu 3 ] (4Àx) have also been synthesized. Their critical temperatures have been found to vary almost linearly with x. The x dependence of the coercive field has also been investigated and analyzed.

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Synthesis and Structural Study by Wide-Angle X-ray Scattering (WAXS) of Polymeric {Ln2[M(opba)]3}·S Compounds Containing 4f LnIII and 3d MII {Ln2[M(opba)]3}·S Ions [opba =ortho-Phenylenebis(oxamato), S = Solvent Molecules]

Kahn

Verelst

Lecante

et al. 1999

Eur. J. Inorg. Chem.

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The compounds of formula Ln2[M(opba)]3·xH2O·yDMSO containing 4f LnIII and 3d MII ions have been synthesized; opba stands for ortho‐phenylenebis(oxamato). These compounds crystallize poorly, and hence structural information has been obtained from the wide angle X‐ray scattering (WAXS) technique. It has been shown that the compounds present the same ladder‐like motif as that previously described for Tm2[Cu(opba)]3·4H2O·10DMF. Changing the LnIII and/or MII ions results in more or less pronounced distortions of the ladders. For a given MII ion, changing the LnIII ion from LaIII to LuIII results in a decrease of the Ln–M distance parallel to the lanthanide contraction. In the same way, for a given rare earth, changing the MII ion from CuII to NiII and ZnII ions also results in the decrease of the Ln–M distance in accord with the decreasing radii of the MII ions. The structural details have been analyzed and discussed.

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Dimensionality of manganese(II)-copper(II) bimetallic compounds and design of molecular-based magnets

Cited by 224 publications

References 1 publication

Synthesis and density functional calculations of the new molecule-based magnet precursor [Fe(H2opba-i)(dmso)2]Cl

Synthesis and density functional calculations of the new molecule-based magnet precursor [Fe(H2opba-i)(dmso)2]Cl

Soft and Hard Molecule-Based Magnets of Formula [(Etrad)2M2{Cu(opba)}3]⋅S [Etrad+=Radical Cation, MII=MnII or CoII, opba=Ortho-phenylenebis(oxamato), S=Solvent Molecules], with a Fully Interlocked Structure

Synthesis and Structural Study by Wide-Angle X-ray Scattering (WAXS) of Polymeric {Ln2[M(opba)]3}·S Compounds Containing 4f LnIII and 3d MII {Ln2[M(opba)]3}·S Ions [opba =ortho-Phenylenebis(oxamato), S = Solvent Molecules]

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