Ferromagnetic coupling in a unique Cu(II) metallacyclophane with functionalized diazamesocyclic ligands formed by Cu(II)-directed self-assembly: magneto-structural correlations for dichloro-bridged Cu(II) dinuclear complexes

Du, Miao; Guo, Yun; Bu, Xian‐He; Ribas, Joan; Monfort, Montserrat

doi:10.1039/b110465a

Cited by 40 publications

(6 citation statements)

References 31 publications

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“…5 In this work, the experimental values 2J = −1.2 cm −1 (with α/R = 32.9°Å −1 ) and 2J = −2.4 cm −1 (with α/R = 34.3°Å −1 ) determined for dichloro-bridged complexes L 1 -Cl and L 2 -Cl respectively are in contrast with the correlation rule for type II compounds previously described 52 and add to other similar cases of inconsistency. 11,54 However, the obtained results are quantitatively in agreement with other type II values, where the exchange interaction within dimer is generally −10 cm −1 < J < 10 cm −1 . 4 For dibromo-bridged copper dimers, the situation is even more complicated.…”

Section: Magneto-structural Correlationsupporting

confidence: 86%

“…7 Magnetostructural correlation in dihalo-bridged copper(II) complexes seems to be more complicated compared to dihydroxo-bridged complexes. [8][9][10][11] It should be noted also, that among dihalobridged complexes, the vast majority of reports are related to dichloro species and considerably less information is available on structural and magnetic properties of dibromo-bridged copper(II) dimers. 10,12 N,N'-disubstituted oxalamides have proved to be very useful ligands in designing homo-and heterometallic complexes.…”

Section: Introductionmentioning

confidence: 99%

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Crystal structures and magnetic properties of a set of dihalo-bridged oxalamidato copper(ii) dimers

et al. 2014

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A set of four copper(II) complexes, L 1 -X and L 2 -X (X = Cl, Br; L 1 = N-(L-leucine methyl ester)-N'-((2-pyridin-2-yl)methyl)oxalamide and L 2 = N-benzyl-N'-((2-pyridin-2-yl)methyl)oxalamide) have been synthesized and characterized by X-ray structural analysis, electron paramagnetic resonance (EPR) spectroscopy on single crystal and by SQUID magnetization measurements. X-ray diffraction studies show one-dimensional hydrogen bonded networks of dimeric copper(II)-complexes bridged by two halide ions and with the two metal centers 3.44-3.69Å apart. The geometry at each copper(II) atom is ideal or near ideal square pyramidal. EPR and SQUID studies indicate that all complexes exhibit weak antiferromagnetic interactions between the Cu(II) paramagnetic centers, with exchange parameter |J| ∼1 cm −1 . Magneto-structural comparisons among similar dihalo-bridged Cu(II) dinuclear complexes are also provided, and a possible correlation has been established.

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Section: Magneto-structural Correlationsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Crystal structures and magnetic properties of a set of dihalo-bridged oxalamidato copper(ii) dimers

et al. 2014

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“…Since the pioneering studies by Fujita and Saalfrank et al on metallamacrocycles, considerable efforts have been focused on designing such compounds. 1e,4c, Complexes 1 and 2 described here are rare water-soluble Cu II metallamacrocycles . Another interesting point is the stacking patterns of the two assembly species in the solid state: (i) For 1 , the cation parts are parallel stacked along a axis about 8.0 Å apart to form a column, and the adjacent columns further interlace, resulting in a quasi 3-D-like arrangement (Figure a).…”

Section: Resultsmentioning

confidence: 92%

From Metallacyclophanes to 1-D Coordination Polymers: Role of Anions in Self-Assembly Processes of Copper(II) and 2,5-Bis(3-pyridyl)-1,3,4-oxadiazole

Bu²,

Huang³

et al. 2002

Inorg. Chem.

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101

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The reaction of various CuII salts with 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (L) in CH3CN-H2O medium affords different complexes, the solid structures of which are controlled only by the choice of the counteranions. Reaction of Cu-(ClO4)2.6H2O or Cu(NO3)2.3H2O and L yields the novel bimetallic macrocyclic complex [Cu2L2(H2O)6](ClO4)4(H2O)4 (1) [monoclinic, space group P21/m, a = 8.745(5) A, b = 16.179(10) A, c = 14.930(8) A, beta = 93.253(10) degrees, Z = 2] or [CuL(NO3)2]2(CH3CN)2 (2) [triclinic, space group P1, a = 7.863(3) A, b = 8.679(3) A, c = 13.375(5) A, alpha = 74.121(5) degrees, beta = 78.407(6) degrees, gamma = 86.307(6) degrees, Z = 1]. However, with the replacement of CuII perchlorate or nitrate salts with CuSO4.5H2O or Cu(OAc)2.H2O in the above reaction, two different one-dimensional (1-D) coordination polymers [[Cu2L2(H2O)6(SO4)2](H2O)6]n (3) [triclinic, space group P1, a = 7.078(3) A, b = 11.565(4) A, c = 12.561(5) A, alpha = 109.511(6) degrees, beta = 105.265(6) degrees, gamma = 94.042(6) degrees, Z = 1] or [[Cu2L(mu-OAc)4]]n (4) [monoclinic, space group C2/c, a = 20.007(7) A, b = 7.506(2) A, c = 16.062(5) A, beta = 108.912(5) degrees, Z = 4] were obtained. These results unequivocally indicate that the nature of the counteranions, which play different roles in each complex, is the key factor governing the structural topologies of them. The magnetic properties of these CuII complexes have been investigated by variable-temperature magnetic susceptibility and magnetization measurements, and the magneto-structural correlation has been analyzed in detail.

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“…The longer Cu–X apical bond lengths (2.6572(4) Å in 1 ; 2.6479(8) Å in 2 ) as compared to the basal Cu–X distances (weighted mean value 2.47(3) Ǻ in 1 ; 2.29(2) Å in 2 ) are associated to the pseudo-Jahn–Teller effect on the copper(II) ion. All Cu–X bond distances are in good agreement with those found in the literature for related bis(μ-bromo)-bis(μ-chloro)copper(II) complexes. − The Cu–Cl–Cu bridging angle of 89.35(3)° in 2 is slightly narrower than the corresponding Cu–Br–Cu angle [92.60(1)°] found in 1 , while the Cl1–Cu–Cl angle of 90.65(3)° is slightly larger than the Br1–Cu1–Br1 ii angle in 1 [87.401(12)°]. It is noteworthy to mention that, in spite of the similar formula units, 1 and 2 are not isostructural.…”

Section: Resultsmentioning

confidence: 99%

Framework Solids Based on Copper(II) Halides (Cl/Br) and Methylene-Bridged Bis(1-hydroxybenzotriazole): Synthesis, Crystal Structures, Magneto-Structural Correlation, and Density Functional Theory (DFT) Studies

et al. 2012

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A methylene-bridged 1-hydroxybenzotriazole derived ligand L [L = 1, 3-bis(benzotriazol-1-yl)-1,3-dioxapropane] has been synthesized and characterized by spectroscopic and structural methods. Reaction of L with two different copper(II) halides [CuX(2); X = Br, Cl] in an identical condition yields two different compounds of similar compositions, {[Cu(μ-Br)(Br)(μ-L)](2)}(n)·2nH(2)O (1) and {[Cu(μ-Cl)(Cl)(μ-L)](2)}(n)·2nH(2)O (2), both being characterized by various physicochemical techniques. Single crystal X-ray studies reveal that they appear as 2D coordination polymers with similar bridging fashion of L. Low temperature magnetic susceptibility measurements reveal antiferromagnetic and ferromagnetic behaviors for 1 and 2 with magnetic coupling constants J = -15.2 and +1.7 cm(-1), which are in a reasonable agreement with their calculated values (J = -9.79 and +0.68 cm(-1) respectively, for 1 and 2). The role of bridging halides in the structure and magnetic properties of the complexes are investigated, and a possible magneto-structural correlation has been established. Influence of spin density of bridging halides on the magnitude of coupling constants has been discussed with the help of density functional theory (DFT) calculations.

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Ferromagnetic coupling in a unique Cu(II) metallacyclophane with functionalized diazamesocyclic ligands formed by Cu(II)-directed self-assembly: magneto-structural correlations for dichloro-bridged Cu(II) dinuclear complexes

Cited by 40 publications

References 31 publications

Crystal structures and magnetic properties of a set of dihalo-bridged oxalamidato copper(ii) dimers

Crystal structures and magnetic properties of a set of dihalo-bridged oxalamidato copper(ii) dimers

From Metallacyclophanes to 1-D Coordination Polymers: Role of Anions in Self-Assembly Processes of Copper(II) and 2,5-Bis(3-pyridyl)-1,3,4-oxadiazole

Framework Solids Based on Copper(II) Halides (Cl/Br) and Methylene-Bridged Bis(1-hydroxybenzotriazole): Synthesis, Crystal Structures, Magneto-Structural Correlation, and Density Functional Theory (DFT) Studies

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