scholarly journals A Novel Family of Triangular CoII2LnIII and CoII2YIII Clusters by the Employment of Di-2-Pyridyl Ketone

2019 ◽  
Vol 5 (2) ◽  
pp. 35 ◽  
Author(s):  
Constantinos G. Efthymiou ◽  
Áine Ní Fhuaráin ◽  
Júlia Mayans ◽  
Anastasios Tasiopoulos ◽  
Spyros P. Perlepes ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Solid State ◽  
Structural Characterization ◽  
Metal Clusters ◽  
Variable Temperature ◽  
Ac Susceptibility ◽  
Exchange Interactions ◽  
Ac Magnetic Susceptibility ◽  
Ferromagnetic Exchange ◽  
Weak Ferromagnetic

The synthesis, structural characterization and magnetic study of novel CoII/4f and CoII/YIII clusters are described. In particular, the initial employment of di-2-pyridyl ketone, (py)2CO, in mixed metal Co/4f chemistry, provided access to four triangular clusters, [CoII2MIII{(py)2C(OEt)(O)}4(NO3)(H2O)]2[M(NO3)5](ClO4)2 (M = Gd, 1; Dy, 2; Tb, 3; Y, 4), where (py)2C(OEt)(O)− is the monoanion of the hemiketal form of (py)2CO. Clusters 1–4 are the first reported Co/4f (1–3) and Co/Y (4) species bearing (py)2CO or its derivatives, despite the fact that over 200 metal clusters bearing this ligand have been reported so far. Variable-temperature, solid-state dc and ac magnetic susceptibility studies were carried out on 1–4 and revealed the presence of weak ferromagnetic exchange interactions between the metal ions (JCo-Co = +1.3 and +0.40 cm−1 in 1 and 4, respectively; JCo-Gd = +0.09 cm−1 in 1). The ac susceptibility studies on 2 revealed nonzero, weak out-of-phase (χ’’M) signals below ~5 K.

scholarly journals Supramolecular Assemblies of Trinuclear Copper(II)-Pyrazolato Units: A Structural, Magnetic and EPR Study

Chemistry ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 626-644
Author(s):  
Kaige Shi ◽  
Logesh Mathivathanan ◽  
Radovan Herchel ◽  
Athanassios K. Boudalis ◽  
Raphael G. Raptis
Keyword(s):  
Magnetic Susceptibility ◽  
Solid State ◽  
Dft Calculations ◽  
Variable Temperature ◽  
One Dimensional ◽  
Frozen Solution ◽  
Variable Temperature Magnetic Susceptibility ◽  
Anionic Complexes ◽  
Weak Ferromagnetic ◽  
Exchange Parameters

Two anionic complexes, {[Cu3(µ3-OH)(µ-4-Ph-pz)3Cl3]2[Cu(4-Ph-pzH)4](µ-Cl)2}2− (1) and [Cu3(µ3-OH)(µ-pz)3(µ1,1-N3)2(N3)]− (2), crystallize as one-dimensional polymers, held together by weak Cu-(µ-Cl) and Cu-(µ-N3) interactions, respectively. Variable temperature magnetic susceptibility analyses determined the dominant antiferromagnetic intra-Cu3 exchange parameters in the solid state for both complexes, whereas the weak ferromagnetic inter-Cu3 interactions manifested also in the solid state EPR spectra, are absent in the corresponding frozen solution spectra. DFT calculations were employed to support the results of the magnetic susceptibility analyses.

scholarly journals Field-Induced Single-Ion Magnet Phenomenon in Hexabromo- and Hexaiodorhenate(IV) Complexes

2020 ◽  
Vol 6 (2) ◽  
pp. 20
Author(s):  
Carlos Rojas-Dotti ◽  
Adrián Sanchis-Perucho ◽  
Marta Orts-Arroyo ◽  
Nicolás Moliner ◽  
Ricardo González ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
General Formula ◽  
Crystal Packing ◽  
Variable Temperature ◽  
Magnetic Behaviour ◽  
Octahedral Geometry ◽  
Organic Cations ◽  
Ac Magnetic Susceptibility ◽  
Halide Ions ◽  
Triclinic System

Two mononuclear ReIV complexes of general formula (PPh4)2[ReX6] [PPh4+ = tetraphenylphosphonium cation, X = Br (1) and I (2)] have been prepared and structurally and magnetically characterised. Both compounds crystallise in the triclinic system with space group Pī. Their structures are made up of hexahalorhenate(IV), [ReX6]2−, anions, and bulky PPh4+ cations. Each ReIV ion in 1 and 2 is six-coordinate and bonded to six halide ions in a quasi regular octahedral geometry. In their crystal packing, the [ReX6]2− anions are well separated from each other through the organic cations, generating alternated anionic and cationic layers, and no intermolecular Re−X···X−Re interactions are present. Variable-temperature dc magnetic susceptibility measurements performed on microcrystalline samples of 1 and 2 show a very similar magnetic behaviour, which is typical of noninteracting mononuclear ReIV complexes with S = 3/2. Ac magnetic susceptibility measurements reveal the slow relaxation of the magnetisation in the presence of external dc fields for 1 and 2, hence indicating the occurrence of the field-induced single-ion magnet (SIM) phenomenon in these hexabromo- and hexaiodorhenate(IV) complexes.

THE EFFECT OF PARTIAL ATOMIC SUBSTITUTION ON ELECTRIC AND MAGNETIC PROPERTIES OF (Bi,Pb):2223 SINTERED SUPERCONDUCTORS

2003 ◽  
Vol 17 (26) ◽  
pp. 4675-4681 ◽  
Author(s):  
A. V. POP ◽  
M. POP ◽  
I. I. GERU
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Electrical Resistance ◽  
Ac Susceptibility ◽  
Partial Substitution ◽  
Superconducting Transition ◽  
Ac Magnetic Susceptibility ◽  
Atomic Concentration ◽  
Susceptibility Data ◽  
Atomic Substitution

The effect of partial substitution of Ca by x = 0.02 La on the electrical and magnetically properties of two (Bi,Pb):2223 superconductor ceramic S1 and S2 (with different Pb and Sr atomic concentration) were investigated by using electrical resistance and AC magnetic susceptibility measurements. The parameters from linear resistivity data in the normal state and superconducting transition are sensitive to the compounds stoechiomerty. The intergrain critical current density JcJ(T) dependence near Tc obtained from immaginary AC susceptibility data agrees with the assumption of SNS intergrain junctions.

scholarly journals Low pH constructed Co(ii) and Ni(ii) 1D coordination polymers based on Cα-substituted analogues of zoledronic acid: structural characterization, and spectroscopic and magnetic properties

RSC Advances ◽  
2019 ◽  
Vol 9 (54) ◽  
pp. 31497-31510 ◽  
Author(s):  
Tomasz Rojek ◽  
Waldemar Goldeman ◽  
Katarzyna Ślepokura ◽  
Marek Duczmal ◽  
Agnieszka Wojciechowska ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Zoledronic Acid ◽  
Coordination Polymers ◽  
Structural Characterization ◽  
Exchange Interactions ◽  
Low Ph ◽  
Metal Centers ◽  
Ferromagnetic Exchange

1D Co(ii)/Ni(ii) coordination polymers with alternating antiferromagnetic–ferromagnetic exchange interactions between metal centers propagated through double (–O–P–O–)2 bridges.

Structural characterization of polyallene in the solid state as studied by variable-temperature high-resolution carbon-13 NMR spectroscopy

1991 ◽  
Vol 24 (8) ◽  
pp. 2011-2014 ◽  
Author(s):  
Kyung Hoon Min ◽  
Hiromichi Kurosu ◽  
Isao Ando ◽  
Takakazu Yamamoto ◽  
Takaki Kanbara
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
High Resolution ◽  
Structural Characterization ◽  
Variable Temperature

Superconductivity in Y-Ba-Cu-Ag-O and Y-Ba-Cu-Pt-O Systems

1987 ◽  
Vol 99 ◽  
Author(s):  
V. T. Kovachev ◽  
M. M. Gospodinov ◽  
E. S. Vlachov ◽  
V. A. Lovchinov ◽  
P. K. Svestarov ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Transition Temperature ◽  
Solid State ◽  
Superconducting State ◽  
High Purity ◽  
Solid State Synthesis ◽  
Pure Oxygen ◽  
Ac Magnetic Susceptibility ◽  
Source Materials

A STUDY OF THE Y-Ba-Cu-Ag-O SYSTEM: The specimens studied were produced using the standard ceramic technique. High purity source materials Y2O3, BaCO3CuO, and Ag2O were used. Solid state synthesis was carried out at 900 C for six hours in oxygen ambient. Pressed samples of 16 mm diameter and 2 mm thick were processed in an atmosphere of pure oxygen at 950 C for 12 hours. The transition temperature to the superconducting state was measured by the four point probe resistance technique. The ac magnetic susceptibility was determined by the method outlined in [1].

Rhenium-platinum mixed-metal clusters. Synthesis and solid-state structural characterization of [Re2Pt(.mu.-H)2(CO)8(COD)] and [Re3Pt(.mu.-H)3(CO)14] (COD = 1,5-cyclooctadiene)

1992 ◽  
Vol 11 (5) ◽  
pp. 1777-1784 ◽  
Author(s):  
Patrizia Antognazza ◽  
Tiziana Beringhelli ◽  
Giuseppe D'Alfonso ◽  
Anna Minoja ◽  
Gianfranco Ciani ◽  
...  
Keyword(s):  
Solid State ◽  
Structural Characterization ◽  
Metal Clusters ◽  
Mixed Metal ◽  
Mixed Metal Clusters

Synthesis, structure, photoluminescent, optical and magnetic properties of a novel thulium p-hydroxybenzenesulfonate complex

2019 ◽  
Vol 234 (3) ◽  
pp. 177-182
Author(s):  
Rong-Hua Hu ◽  
Wen-Tong Chen ◽  
Jian-gen Huang
Keyword(s):  
Magnetic Susceptibility ◽  
Solid State ◽  
Diffuse Reflectance ◽  
Magnetic Measurements ◽  
Variable Temperature ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray ◽  
Elemental Analyses ◽  
Anti Stokes

Abstract A novel thulium p-hydroxybenzenesulfonate complex [Tm(C6H5O4S)2(H2O)6](C6H5O4S)·3H2O (1) was solvothermally synthesized and characterized by elemental analyses, photoluminescence, solid-state UV/vis diffuse reflectance, magnetic measurements and single-crystal X-ray diffraction. Complex 1 features an ionic structure with the thulium ion possessing a square antiprismatic geometry. Complex 1 crystallized in the monoclinic system with space group P21. Photoluminescent measurements with solid-state sample demonstrate that the anti-Stokes emission bands in the red/NIR spectral region 710 and 812 nm are observed from the Tm3+ 4f intrashell transitions from the 3F2,3 excited states to the 3H6 and 1G4 excited state to the 3H5 state, respectively. Solid-state UV/vis diffuse reflectance spectra of complex 1 show the existence of a wide optical band gap of 3.56 eV. Variable-temperature magnetic susceptibility and field dependence magnetization measurements are also studied and the magnetic susceptibility obeys the Curie-Weiss law (χm=c/(T−θ)) with the value C being of 8.6 K and a negative Weiss constant θ being of −0.2 K.

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