scholarly journals Cobalt(II) Complexes Based on Benzylmalonate Anions Exhibiting Field-Induced Single-Ion Magnet Slow Relaxation Behavior

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1130
Author(s):  
Ekaterina Zorina-Tikhonova ◽  
Anna Matyukhina ◽  
Ivan Skabitskiy ◽  
Maksim Shmelev ◽  
Denis Korchagin ◽  
...  
Keyword(s):  
Molecular Complex ◽  
Magnetic Relaxation ◽  
Ac Susceptibility ◽  
Relaxation Behavior ◽  
Magnetic Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Susceptibility Data ◽  
Molecular And Crystal Structures ◽  
2D Polymer

The reaction of (NBu4)2Bzmal (where Bzmal2− is benzylmalonate dianion) with Co(OAc)2∙4H2O gives the [Co(Bzmal)(EtOH)(H2O)]n 2D-polymer (1). The addition of 2,2′-bipyridine (bpy) to the starting system results in the [Co(Bzmal)(bpy)2]·H2O·EtOH molecular complex (2). Their molecular and crystal structures were analyzed by single-crystal X-ray crystallography. An analysis of the static magnetic data supported by the SA-CASSCF/NEVPT2 calculations revealed the presence of easy-plane magnetic anisotropy in both complexes. The AC susceptibility data confirm that both complexes show a slow field-induced (HDC = 1000 Oe) magnetic relaxation behavior.

scholarly journals Synthesis, Crystal Structure and Magnetic Behaviour of Dimeric and Polymeric Gadolinium Trifluoroacetate Complexes

2006 ◽  
Vol 61 (6) ◽  
pp. 699-707 ◽  
Author(s):  
Daniela John ◽  
Alexander Rohde ◽  
Werner Urland
Keyword(s):  
Crystal Structure ◽  
Magnetic Behaviour ◽  
Magnetic Data ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
Temperature Range ◽  
X Ray Crystallography ◽  
Carboxylate Groups

The gadolinium(III) trifluoroacetates ((CH3)2NH2)[Gd(CF3COO)4] (1), ((CH3)3NH)[Gd(CF3 COO)4(H2O)] (2), Gd(CF3COO)3(H2O)3 (3) as well as Gd2(CF3COO)6(H2O)2(phen)3 · C2H5OH (4) (phen = 1,10-phenanthroline) were synthesized and structurally characterized by X-ray crystallography. These compounds crystallize in the space group P1̅ (No. 2, Z = 2) (1, 2 and 4) and P 21/c (No. 14, Z = 4) (3), respectively, with the following lattice constants 1: a = 884.9(2), b = 1024.9(2), c = 1173.1(2) pm, α = 105.77(2), β = 99.51(2), γ = 107.93(2)°; 2: a = 965.1(1), b = 1028.6(1), c = 1271.3(2) pm, α = 111.83(2), β = 111.33(2), γ = 90.44(2)°; 3: a = 919.6(2), b = 1890.6(4), c = 978.7(2) pm, β = 113.94(2)°; 4: a = 1286.7(8), b = 1639.3(8), c = 1712.2(9) pm, α = 62.57(6), β = 84.13(5), γ = 68.28(5)°. The compounds consist of Gd3+ ions which are bridged by carboxylate groups either to chains (1 and 2) or to dimers (3 and 4). In addition to the Gd3+ dimers, compound (4) also contains monomeric Gd3+ units. The magnetic behaviour of 2 and 3 was investigated in a temperature range of 1.77 to 300 K. The magnetic data for these compounds indicate weak antiferromagnetic interactions

Oligometallic cobalt 3,5-dimethylpyrazolate complexes: synthesis, structural and magnetic studies

1993 ◽  
Vol 71 (9) ◽  
pp. 1425-1436 ◽  
Author(s):  
Martin K. Ehlert ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
Robert C. Thompson ◽  
James Trotter
Keyword(s):  
Magnetic Data ◽  
Antiferromagnetic Coupling ◽  
Antiferromagnetic Exchange ◽  
Nearest Neighbour ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
Dimer Model ◽  
Space Group ◽  
X Ray ◽  
Susceptibility Data

Three oligometallic 3,5-dimethylpyrazolate (dmpz) bridged Co(II) compounds have been synthesized and characterized spectroscopically: dimeric [Co(dmpz)2(Hdmpz)]2, the related oligometallic compound, Co(dmpz)2•0.344(Hdmpz), and the trimetallic [Co(dmpz)2Cl(Hdmpz)]2Co. The first and last of these compounds have been studied magnetically and by single crystal X-ray diffraction. Crystals of [Co(dmpz)2(Hdmpz)]2 are orthorhombic, a = 17.022(1), b = 29.224(2), c = 13.576(3) Å, Z = 8, space group Fddd; and those of [Co(dmpz)2Cl(Hdmpz)]2Co are triclinic, a = 11.742(3), b = 18.604(4), c = 8.950(2) Å, α = 99.76(2)°, β = 102.32(2)°, γ = 93.36(2)°, Z = 2, space group [Formula: see text] The structures were solved by the Patterson method and were refined by full-matrix least-squares procedures to R = 0.035 and 0.042 (Rw = 0.034, 0.047) for 938 and 3853 reflections with I ≥ 3σ(F2), respectively. Magnetic susceptibility studies on the dimeric and trimetallic complex show them to exhibit antiferromagnetic behaviour. Analysis of the magnetic data (2– 300 K) for the trimetallic complexes reveals antiferromagnetic coupling between the terminal and central Co(II) ions with J (Heisenberg) ≈ −3 cm−1. Either intramolecular next-nearest neighbour or intermolecular antiferromagnetic exchange is also present in this compound. The dimeric complex shows significant antiferromagnetic exchange between cobalt centres. Susceptibility data over the range 12–300 K are adequately modelled with the Ising S = 1/2 dimer model (J ≈ −23 cm−1).

Synthesis, Characterization, Crystal Structure and Magnetic Properties of [(en)CuII(ImH)2](ClO4)2 (en = Ethylenediamine, ImH = Imidazole): A Metalloligand as a Building Block for Heterometal Chains

2003 ◽  
Vol 58 (6) ◽  
pp. 505-510 ◽  
Author(s):  
Thorsten Glaser ◽  
Maik Heidemeier ◽  
F. Ekkehardt Hahn ◽  
Tania Pape ◽  
Thomas Lügger
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Building Block ◽  
Exchange Interactions ◽  
High Yield ◽  
Magnetic Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Structural And Electronic Properties ◽  
Dark Blue

The reaction of Cu(ClO4)2·6H2O, imidazole (ImH), and ethylenediamine (en) in a 1 : 2 : 1 ratio afforded in high yield dark-blue single-crystals of [(en)CuII(ImH)2](ClO4)2, 1, which can be used after deprotonation as a building block for heterometallic ferrimagnetic chains. The structural and electronic properties of 1 were examined by X-ray crystallography, FTIR, ESI-MS, electrochemistry, UV/vis/NIR, EPR, and magnetic susceptibility measurements. The structure of 1 exhibits intermolecular π-π interactions and hydrogen bonds but the magnetic data exclude the presence of intermolecular exchange interactions.

scholarly journals Effect of the ruffled porphyrin ring on electronic structures: structure and characterization of [Fe(TalkylP)(OClO3)] and [Fe(TPrP)(THF)2]ClO4 (alkyl = Ethyl, Et and n-Propyl, Pr)

2013 ◽  
Vol 17 (01n02) ◽  
pp. 118-124 ◽  
Author(s):  
Ming Li ◽  
Allen G. Oliver ◽  
Teresa J. Neal ◽  
Charles E. Schulz ◽  
W. Robert Scheidt
Keyword(s):  
Electronic Structures ◽  
Structural Parameters ◽  
Structural Features ◽  
Magnetic Data ◽  
Porphyrin Ring ◽  
Magnetic Susceptibilities ◽  
X Ray ◽  
X Ray Crystallography ◽  
Intermediate Spin

We report the synthesis of Fe(TalkylP)(OClO3)] (alkyl = ethyl and propyl) and [Fe(TPrP)(THF)2]ClO4 , which are characterized by UV-vis, EPR, X-ray crystallography, and solid-state magnetic susceptibilities. The macrocycles of all three complexes are ruffled, all of the structural features for [Fe(TEtP(OClO3)] and [Fe(TPrP)(OClO3)] are characteristic of the nearly pure S = 3/2 state, while the structural parameters for [Fe(TPrP)(THF)2]ClO4 feature a pure intermediate-spin (S = 3/2) state, which are all consistent with EPR and magnetic data. It is clear from these studies that the ruffled conformation plays a significant role in affecting the extent of S = 3/2 character.

SYNTHESIS OF NOVEL MANGANESE-BASED SINGLE-MOLECULE NANOMAGNETS

2002 ◽  
Vol 01 (05n06) ◽  
pp. 455-459 ◽  
Author(s):  
JINKWON KIM ◽  
HAENGKYU CHO ◽  
AHKILESH K. GUPTA ◽  
JIN MOOK LIM ◽  
YOUNGKYU DO
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Anisotropy ◽  
Single Crystal ◽  
Single Molecule ◽  
Ac Susceptibility ◽  
Ac Magnetic Susceptibility ◽  
Temperature Dependent ◽  
X Ray ◽  
X Ray Crystallography

New Mn12 single-molecule nanomagnets [ Mn 12 O 12( O 2 CCHCl 2)( H 2 O )4]· 2CH 2 Cl 2· H 2 O and [ Mn 12 O 12( O 2 CCHCl 2)( H 2 O )4]· 2CH 3 C 6 H 5· 4H 2 O and novel Mn18 complexes [ M 18 O 14( O 2 CR )18( hmp )4( hmpH )2( H 2 O )2] (R=Me, Et) have been synthesized and characterized by single crystal X-ray crystallography and dc- and ac-magnetic susceptibility measurements. Mn12 complexes show characteristic SMM properties, such as temperature-dependent out-of-phase ac-susceptibility. Mn18 does not show relaxation behaviors down to 2.0 K, but reveals magnetic anisotropy in reduced magnetization experiment.

Coordination chemistry of thioether–pyridazine macrocycles II. Synthesis, structural and spectroscopic studies of dinuclear copper(II) and polynuclear copper(I) and silver(I) complexes of a tetrathiapyridazinophane macrocyclic ligand

1992 ◽  
Vol 70 (11) ◽  
pp. 2709-2716 ◽  
Author(s):  
Liqin Chen ◽  
Laurence K. Thompson ◽  
John N. Bridson
Keyword(s):  
Macrocyclic Ligand ◽  
Silver Ions ◽  
Spectroscopic Studies ◽  
Binuclear Complexes ◽  
Monoclinic System ◽  
Magnetic Susceptibility Data ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Susceptibility Data

The preparation and properties of the thioether–pyridazine macrocycle (L3; C11H16N2S4) containing one pyridazine subunit, and its copper(II), copper(I), and silver(I) complexes are described. Magnetic susceptibility data (5–300 K) for the binuclear complexes [CuL3Cl2]2 (I) and [CuL3Br2]2 (II) have been fitted to the Friedberg magnetization expression with a molecular field correction. Intradimer antiferromagnetic exchange is weak (−2J < 18 cm−1), with even weaker interdimer exchange (−zJ′ < 0.3 cm−1). The complexes [CuL3Cl]x (III) and [AgL3ClO4]x (V) have been characterized by X-ray crystallography. III crystallizes in the triclinic system, space group [Formula: see text], with a = 9.410(2) Å, b = 10.291(2) Å, c = 9.208(2) Å, α = 108.56(1)°, β = 91.82(2)°, γ = 68.04(1)°, V = 780.1(2) Å3, and Z = 2(R = 0.035, Rw = 0.031 for 1856 reflections). The ligand acts as a bidentate, S2, bridge between dinuclear Cu2Cl2 units in a double stranded polymer. III crystallized in the monoclinic system, space group P21/n, with a = 9.382(4) Å, b = 19.274(4) Å, c = 10.190(3) Å, β = 106.35(3)°, V = 1768(1) Å3, and Z = 4 (R = 0.036, Rw = 0.029 for 1776 reflections). The structure consists of a polymeric, two dimensional sheet structure, involving pseudo-tetrahedral silver ions linked by exo-bidentate, S2, ligands and bidentate perchlorates.

scholarly journals Syntheses, Structures, and Magnetic Properties of a Series of Heterotri-, Tetra- and Pentanuclear LnIII–CoII Compounds

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 196 ◽  
Author(s):  
Yun Xu ◽  
Luo Feng ◽  
Ji-Min Zheng
Keyword(s):  
Magnetic Properties ◽  
Ir Spectroscopy ◽  
Single Crystal ◽  
Magnetic Relaxation ◽  
Magnetic Measurements ◽  
Relaxation Behavior ◽  
Structural Motif ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray

Three types of Ln(III)–Co(II) heterometallic compounds, LnCo2(L1)7(bipy)2 (Ln = Pr-1, Eu-2, Sm-3, Gd-4, Tb-5, Dy-6) (L1 = 4-chlorobenzoate, bipy = 2,2′-bipyridine), Ln2Co2(L2)10(bipy)2 (Ln = Sm-7, Gd-8, Tb-9, Dy-10, Ho-11, Er-12, Yb-13), (L2 = 2,4-dichlorobenzoate, bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline), and Ln2Co3(L1)12(bipy)2 (Ln = Ho-14, Er-15, Yb-16), were synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction, IR spectroscopy and magnetic measurements. Structural analyses revealed that 14–16 take on a unique linear pentanuclear structural motif. Interestingly, the Ho-containing compound 14 exhibits magnetic relaxation behavior.

Crystal structures and property characterization of two magnetic frustration compounds

2018 ◽  
Vol 33 (3) ◽  
pp. 190-194
Author(s):  
Kunkun Li ◽  
Duanduan Yuan ◽  
Shijie Shen ◽  
Jiangang Guo
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ac Susceptibility ◽  
Weiss Temperature ◽  
Freezing Transition ◽  
X Ray ◽  
Susceptibility Data ◽  
Antiferromagnetic Materials ◽  
Spin Freezing ◽  
Property Characterization

We report the structure and physical properties of two quasi-two-dimensional triangular antiferromagnetic materials, Co0.66Al2Se3.53 and Ni0.61Al2Se3.55, which show highly magnetically frustrated characters. Powder X-ray diffractions demonstrate that Co0.66Al2Se3.53 and Ni0.61Al2Se3.55 possess identical space group of P-3m1 with lattice parameters a = 3.8089(1) Å, c = 12.676(1) Å and a = 3.7880(1) Å, c = 12.650(1) Å, respectively. Analyzing the susceptibility data of Co0.66Al2Se3.53 reveal a Curie Weiss temperature of −216 K, and a spin-freezing transition temperature of 4.5 K, giving a frustration index f = −θcw/Tf ≈ 48. Ni0.61Al2Se3.55 possesses an effective moment of 2.38 µB, a Curie–Weiss temperature of −62 K with no sign of spin-freezing transition down to 2 K. The AC susceptibility data of Co0.66Al2Se3.53 suggest a spin glass-like transition, but no intersite mixing between Co2+ and Al3+ was observed from the X-ray photoelectron spectroscopy measurements.

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