Molecular Engineering To Control the Magnetic Interaction between Single-Chain Magnets Assembled in a Two-Dimensional Network

2012 ◽  
Vol 134 (37) ◽  
pp. 15265-15268 ◽  
Author(s):  
Luminita M. Toma ◽  
Catalina Ruiz-Pérez ◽  
Jorge Pasán ◽  
Wolfgang Wernsdorfer ◽  
Francesc Lloret ◽  
...  
2016 ◽  
Vol 52 (56) ◽  
pp. 8722-8725 ◽  
Author(s):  
Lei Su ◽  
Wei-Chao Song ◽  
Jiong-Peng Zhao ◽  
Fu-Chen Liu

A synthetic strategy of control of the arrangement and the magnetism of the SCMs by assembly of the chains into a high dimensional network was illustrated in a family of a weak antiferromagnetic chain based 3D framework.


2008 ◽  
Vol 80 (11) ◽  
pp. 2297-2308 ◽  
Author(s):  
Takashi Kajiwara ◽  
Hiroki Tanaka ◽  
Masahiro Yamashita

A novel class of single-chain magnets (SCMs), catena-[FeII(ClO4)2{FeIII(bpca)2}]ClO4 and its derivative, were synthesized using the spin-carrier components possessing hard-axis anisotropy (or easy-plane anisotropy, D > 0). The easy-axis-type anisotropy of whole molecules of these compounds, which is essential for the formation of SCMs, arises from the twisted arrangement of easy-planes of Fe(II) along the chain axis. Alternating high-spin Fe(II) and low-spin Fe(III) chain complexes behave as an SCM with a typical frequency-dependent ac susceptibility which obeys Arrhenius law. Below 7 K, catena-[FeII(ClO4)2{FeIII(bpca)2}]ClO4 showed a short-range spin-ordering even in zero external field in a time range of Mössbauer spectroscopy as well as the muon-spin-relaxation (μSR) spectroscopy. Since the easy-axis-type magnetic anisotropy originated from the structural motif of the twisting arrangement of Fe(II) ions, the overall magnetic property was very sensitive to the small structural changes arising from adsorption/desorption of the crystal solvents, and catena-[FeII(ClO4)2{FeIII(bpca)2}]ClO4 showed a reversible change in magnetism that has been referred to as "a magnetic sponge". In its derivative, controls of the molecular structure, the arrangement of chains in the crystal, and magnetic properties both in dc and ac susceptibility have been achieved by the introduction of methyl group on a bpca- ligand, which bridges and mediates the magnetic interaction of the adjoining Fe(II)/Fe(III) ions.


2011 ◽  
Vol 47 (22) ◽  
pp. 6386 ◽  
Author(s):  
Yan-Qin Wang ◽  
Wei-Wei Sun ◽  
Zhen-Dong Wang ◽  
Qin-Xiang Jia ◽  
En-Qing Gao ◽  
...  

Author(s):  
P. F. Flicker ◽  
V.S. Kulkarni ◽  
J. P. Robinson ◽  
G. Stubbs ◽  
B. R. DasGupta

Botulinum toxin is a potent neurotoxin produced by Clostridium botulinum. The toxin inhibits release of neurotransmitter, causing muscle paralysis. There are several serotypes, A to G, all of molecular weight about 150,000. The protein exists as a single chain or or as two chains, with two disulfide linkages. In a recent investigation on intracellular action of neurotoxins it was reported that type B neurotoxin can inhibit the release of Ca++-activated [3H] norepinephrine only if the disulfide bonds are reduced. In order to investigate possible structural changes in the toxin upon reduction of the disulfide bonds, we have prepared two-dimensional crystals of reduced type B neurotoxin. These two-dimensional crystals will be compared with those of the native (unreduced) type B toxin.


2014 ◽  
Vol 70 (12) ◽  
pp. o1252-o1252 ◽  
Author(s):  
Rodolfo Moreno-Fuquen ◽  
Diego F. Sánchez ◽  
Javier Ellena

In the title compound, C10H6N4O5S, the mean plane of the non-H atoms of the central amide fragment C—N—C(=O)—C [r.m.s. deviation = 0.0294 Å] forms dihedral angles of 12.48 (7) and 46.66 (9)° with the planes of the thiazole and benzene rings, respectively. In the crystal, molecules are linked by N—H...O hydrogen bonds, forming chains along [001]. In addition, weak C—H...O hydrogen bonds link these chains, forming a two-dimensional network, containingR44(28) ring motifs parallel to (100).


Author(s):  
Dong Liu

Solvothermal reaction between Cd(NO3)2, 1,4-phenylenediacetate (1,4-PDA) and 1,3-bis(pyridin-4-yl)propane (bpp) afforded the title complex, [Cd(C10H8O4)(C13H14N2)]n. Adjacent carboxylate-bridged CdIIions are related by an inversion centre. The 1,4-PDA ligands adopt acisconformation and connect the CdIIions to form a one-dimensional chain extending along thecaxis. These chains are in turn linked into a two-dimensional network through bpp bridges. The bpp ligands adopt ananti–gaucheconformation. From a topological point of view, each bpp ligand and each pair of 1,4-PDA ligands can be considered as linkers, while the dinuclear CdIIunit can be regarded as a 6-connecting node. Thus, the structure can be simplified to a two-dimensional 6-connected network.


2014 ◽  
Vol 70 (8) ◽  
pp. o875-o876 ◽  
Author(s):  
Naresh Sharma ◽  
Goutam Brahmachari ◽  
Bubun Banerjee ◽  
Rajni Kant ◽  
Vivek K. Gupta

In the title compound, C17H18N4O4, the dihedral angle between the benzene ring and 2,4-dihydropyrano[2,3-c]pyrazole ring system is 89.41 (7)°. The pyran moiety adopts a strongly flattened boat conformation. In the crystal, molecules are linked by N—H...N, N—H...O, C—H...N and C—H...O hydrogen bonds into an infinite two-dimensional network parallel to (110). There are π–π interactions between the pyrazole rings in neighbouring layers [centroid–centroid distance = 3.621 (1) Å].


2008 ◽  
Vol 361 (14-15) ◽  
pp. 3997-4003 ◽  
Author(s):  
G. Calvez ◽  
K. Bernot ◽  
O. Guillou ◽  
C. Daiguebonne ◽  
A. Caneschi ◽  
...  

1991 ◽  
Vol 44 (12) ◽  
pp. 1783 ◽  
Author(s):  
XM Chen ◽  
TCW Mak

The complex silver(I) 3-carboxylato-1-pyridinioacetate monohydrate, [Ag{C5H4(COO)NCH2.COO}]n.nH2O, crystallizes in space group P21/c (No. 14), with Z-4, a 12.233(6), b 5.049(1), c 14.418(7)Ǻ, and β 94.96(4)°; the structure was refined to RF -0.057 for 1721 observed [I ≥ 3σ(I)] Mo Kα data. The silver(I) atom is coordinated by four carboxylato oxygen atoms in a distorted tetrahedral environment [Ag-O 2.284(5)-2.570(5)Ǻ]. The tridentate acetato group bridges the Ag1 atoms into a zigzag chain featuring an uncommon [Ag2( carboxylato -O,O′)(carboxylato-μ-1,1-O)] six- membered ring, and the coordination sphere about each metal centre is completed by the unidentate aromatic carboxylato group, resulting in a two-dimensional network in the solid. The lattice water molecule forms hydrogen bonds with the uncoordinated oxygen atom of the aromatic carboxylato group [2.755(9)Ǻ] and the coordinated oxygen atom of the acetato group [2.936(9)Ǻ].


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