Two new .mu.-azido nickel(II) uniform chains: syntheses, structures, and magneto-structural correlations

Escuer, Albert; Vicente, Ramón; Ribas, Joan; Fallah, M. Salah El; Soláns, Xavier; Font-Bardı́a, Mercè

doi:10.1021/ic00069a030

Cited by 158 publications

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“…After 3 days, green yellow crystals suitable for X-ray diffraction were easily separated by decantation from a fine yellow powder and collected. Yield: 0. ; elemental analysis calcd (%) for W 24 Magnetic measurements: Magnetic susceptibility measurements were carried out with a Quantum Design SQUID Magnetometer with an applied field of 1000 G. The independence of the susceptibility value with regard to the applied field was checked at room temperature. The susceptibility data were corrected from the diamagnetic contributions as deduced by using Pascals constant tables.…”

Section: Resultsmentioning

confidence: 99%

“…[24] We must point out here that in our model, in order to avoid overparametrization, the J 3 parameter is related to all the Cu II pairs coupled through the central azido ligand in an end-to-end fashion, irrespective of the torsion angle. Focusing then on the M À N À N bond angle, it has been demonstrated by Escuer et (8)8) is then in agreement with this prediction.…”

Section: à4mentioning

confidence: 99%

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A Nonanuclear Copper(II) Polyoxometalate Assembled Around a μ‐1,1,1,3,3,3‐Azido Ligand and Its Parent Tetranuclear Complex

Dolbecq

Marrot

Rivière

et al. 2005

Chemistry A European J

155

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Reaction of Cu(II), [gamma-SiW10O36]8-, and N3- affords three azido polyoxotungstate complexes. Two of them have been characterized by single-crystal X-ray diffraction. Complex KNaCs10[{gamma-SiW10O36Cu2(H2O)(N3)2}2].26H2O (1) is obtained as crystals in few hours after addition of CsCl. This linear tetranuclear Cu(II) complex consists in two [gamma-SiW10O36Cu2(H2O)(N3)2]6- units connected through two W=O bridges. When the filtrate is left to stand for one night, a new complex is obtained. From both elemental analysis and IR spectroscopy, it has been postulated that this compound could be formulated K(1.5)Cs(5.5)[SiW10O37Cu2(H2O)2(N3)].14 H2O (1 a), showing the loss of one azido ligand per polyoxometalate unit. Finally, when no cesium salt is added to the reaction medium, the nonanuclear complex K12Na7[{SiW8O31Cu3(OH)(H2O)2(N3)}3(N3)].24 H2O (2) is obtained after three days. Compound 2 crystallizes in the R3c space group and consists in three {Cu3} units related by a C3 axis passing through the exceptional mu-1,1,1,3,3,3-azido bridging ligand. Each trinuclear Cu(II) unit is embedded in the [gamma-SiW8O31]10- ligand, an unprecedented tetravacant polyoxometalate, showing that partial decomposition of the [gamma-SiW10O36]8- precursor occurs with time in such experimental conditions. Magnetically, complex 1 behaves as two isolated {Cu2(mu(1,1)-N3)2} pairs in which the metal centers are strongly ferromagnetically coupled (J = +224 cm(-1), g = 2.20), the coupling through the W=O bridges being negligible. The magnetic behavior of complex 2 has also been studied. Relatively weak ferromagnetic couplings (J1 = +1.0 cm(-1), J2 = +20.0 cm(-1), g=2.17) have been found inside the {Cu3} units, while the intertrimeric magnetic interactions occurring through the hexadentate azido ligand have been found to be antiferromagnetic (J3 = -5.4 cm(-1)) and ferromagnetic (J4 = +1.3 cm(-1)) with respect to the end-to-end and end-on azido-bridged Cu(II) pairs, respectively.

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Section: Resultsmentioning

confidence: 99%

Section: à4mentioning

confidence: 99%

A Nonanuclear Copper(II) Polyoxometalate Assembled Around a μ‐1,1,1,3,3,3‐Azido Ligand and Its Parent Tetranuclear Complex

Dolbecq

Marrot

Rivière

et al. 2005

Chemistry A European J

155

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“…The antiferromagnetic interactions operate between Ni II of adjacent chains probably by means of electrostatic (dipolar) interactions between the aromatic ring of the coordinating Schiff base ligand due to a close contact between the parallel aromatic rings from two adjacent chains (the closest distance is 3.41 Å). 9 When present interchain hydrogen bonding interactions also play a vital role in intermolecular antiferromagnetic interaction. In our system, no classical hydrogen bonds are present, but only C-H…N bonds in which d (H-N) is ca.…”

Section: This Journal Is © the Royal Society Of Chemistry 2001mentioning

confidence: 99%

“…The equatorial least-square planes of the two Ni II centres are not parallel and form a dihedral angle of 31. 6,7 The intrachain distance between adjacent nickel centres is 5.662(1) Å.…”

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The first metamagnetic one-dimensional molecular material with nickel(ii) and end-to-end azido bridges

et al. 2001

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A novel single azido bridged one-dimensional Ni(II) chain, which represents the first metamagnetic one-dimensional metal-azido system with only end-to-end azido bridges, has been synthesised and characterised by a low temperature magnetic study.In the last decade chemists have dedicated their efforts to the study of molecular-based magnetic materials owing to the need to understand the fundamental science associated with magnetic interactions between the paramagnetic metal ions and the bridging ligand to develop magneto-structural correlation enabling the designed synthesis of interesting magnetic materials. 1 One strategy for the design of molecular-based magnets involves assembling of paramagnetic metal ions in one-, twoand three-dimensional networks using suitable bridging ligands. 1,2 The azido ligand has been widely used because of its diverse binding modes which yield different types of molecules such as dimers, tetramers, one-, two-, and three-dimensional arrays etc. 3 The prime coordination motif for bridging azido is end-on with ferromagnetic interaction and end-to-end having antiferromagnetic coupling. 4 To the best of our knowledge all compounds of Ni II with end-to-end azido bridges are antiferromagnetic with the exception of two compounds which are weakly ferromagnetic: one is a dimer 5 and the other a onedimensional chain of Ni II using a non-chelating capping ligand. 6 Examples of metamagnetic molecular materials in the metal-azido system with only end-to-end bridging azido mode are still lacking. Here, we report the synthesis, ‡ crystal structure and magnetic properties of a new one-dimensional compound, [Ni(L)(N 3 ) 2 ] n 1 (L is a tridentate Schiff base obtained by condensation of pyridine-2-aldehyde and N,N,2,2-tetramethylpropane-1,3-diamine) which represents the first example of a metamagnetic molecular material of Ni II with only end-to-end azido bridges.A crystal structure determination § reveals that complex 1 is a single azido bridged one-dimensional Ni II chain. A perspective view of the polymeric chain of complex 1 with the atom numbering scheme is shown in Fig. 1. Each nickel atom in the chain has an octahedral coordination environment with a NiN 6 core. In the chain, all nickel atoms are linked to one pendant azido in their axial positions. One nitrogen atom, N(7), of the bridging azido is linked to an equatorial position of one nickel while the other nitrogen atom N(9A) of the same azido is coordinated to an axial position of the neighbouring nickel centre. The equatorial least-square planes of the two Ni II centres are not parallel and form a dihedral angle of 31.3(1)°. The deviation of Ni II from the best fit square plane towards N (4) The thermal variation of c M T is shown in Fig. 2. The nature of the c M T vs. T plot is a signature of global intrachain ferromagnetic interaction. The solid line corresponds to the best fit obtained by considering an uniform ferromagnetically coupled chain of spin triplets (Fig. 2). 8 The best fitting parameters are J = +13.5 cm 21 , g = 2.08 and ...

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“…Kopel et al [10] have reported the mononuclear complex of nickel(II) using 3,2,3-tet (as the primary ligand) and trithiocyanurate dianion as the coligand. Bridged Ni complexes with carbonato, cyanato, azido, vanadate [11][12][13][14], etc. have also been reported.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, crystal, and molecular structure of coordination polymers constructed by self-assembly of NiN4 cores with 2,2′-iminodibenzoate and nitroprusside ions

et al. 2006

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Two coordination compounds of compositions [Ni(L 1 )(idba)(H 2 O)]·1.5 H 2 O (1) and [Ni(L 2 )Fe(CN) 5 NO]· C 2 H 5 OH (2) where L 1 is N, N -bis(3-aminopropyl)ethylenediamine, L 2 is 2, 12-dimethyl-3,7,11,17-tetraazabicyclo [11.3.1]heptadeca-1(17),2,11,13,15-pentaene, and idba 2− is 2,2 -iminodibenzoate have been synthesized and characterized by elemental analysis, IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic space group P2 1 /n (No. 14) with a = 9.810(2) Å, b = 10.230(2) Å, c = 25.350(5) Å, V = 2543.6(9) Å 3 , Z = 4, and R = 0.0727. The nickel atom is six-coordinated by four N atoms of amine and two O atoms of water and idba 2− . The molecular packing of the complex comprises of an infinite one-dimensional layered network in which the molecules in the crystal are held together by a system of hydrogen bonding. Complex 2, however, crystallizes in the space group C2/c (No. 15) of the monoclinic system with a = 19.7990(4) Å, b = 14.9440(3) Å, c = 19.8800(3) Å, V = 5115.90(17) Å 3 , Z = 4, and R = 0.0540. The Ni ion in compound 2 has a slightly distorted octahedral arrangement of the N 4 donor atoms of primary ligand L 2 and two N-donor atoms of the secondary nitroprusside ligand. The structure of 2 displays an extended one-dimensional network formed by linear [ Ni NC Fe CN ] units. A cyclic voltammetric study shows that compound 1 undergoes a quasireversible oxidation attributable to Ni 2+ → Ni 3+ in the range 300-420 mV vs SCE.

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Two new .mu.-azido nickel(II) uniform chains: syntheses, structures, and magneto-structural correlations

Cited by 158 publications

References 0 publications

A Nonanuclear Copper(II) Polyoxometalate Assembled Around a μ‐1,1,1,3,3,3‐Azido Ligand and Its Parent Tetranuclear Complex

A Nonanuclear Copper(II) Polyoxometalate Assembled Around a μ‐1,1,1,3,3,3‐Azido Ligand and Its Parent Tetranuclear Complex

The first metamagnetic one-dimensional molecular material with nickel(ii) and end-to-end azido bridges

Synthesis, crystal, and molecular structure of coordination polymers constructed by self-assembly of NiN4 cores with 2,2′-iminodibenzoate and nitroprusside ions

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