EPR AND MAGNETIC SUSCEPTIBILITY STUDIES OF CALCIUM-BORATE OXIDE GLASSES CONTAINING IRON IONS

2002 ◽  
Vol 16 (07) ◽  
pp. 231-239 ◽  
Author(s):  
I. ARDELEAN ◽  
P. PASCUTA ◽  
M. PETEANU
Keyword(s):  
Magnetic Susceptibility ◽  
Iron Content ◽  
Exchange Interactions ◽  
Ionic Species ◽  
Iron Ions ◽  
Oxide Glasses ◽  
Calcium Borate ◽  
Octahedral Symmetry ◽  
Distorted Octahedral ◽  
Borate Oxide

EPR and magnetic susceptibility measurements have been performed on x Fe 2 O 3·(100-x) [3B2O3·CaO] glasses with 0<x≤40 mol%. The Fe 3+ ions in sites of distorted octahedral symmetry and clustered formations containing both Fe 3+ and Fe 2+ ionic species were found. Dipolar and magnetic super-exchange interactions involving iron ions were revealed to depend on the iron content of the sample.

EPR and Magnetic Susceptibility Investigations of Fe2O3-B2O3-KCl Glasses

2003 ◽  
Vol 17 (16) ◽  
pp. 3049-3056 ◽  
Author(s):  
I. Ardelean ◽  
P. Păşcuţă ◽  
L. V. Giurgiu
Keyword(s):  
Magnetic Susceptibility ◽  
Iron Content ◽  
Exchange Interactions ◽  
Ionic Species ◽  
Iron Ions ◽  
Octahedral Symmetry ◽  
Distorted Octahedral

Glasses of the x Fe 2 O 3·(100-x) [3 B 2 O 3· KCl ] system, with 0 < x ≤ 20 mol%, were investigated by means of EPR and magnetic susceptibility measurements. The Fe 3+ ions in sites of distorted octahedral symmetry and clustered formations containing both Fe 3+ and Fe 2+ ionic species were verified. Dipolar and super-exchange interactions involving iron ions were revealed depending on the iron content of the sample.

EPR AND MAGNETIC SUSCEPTIBILITY STUDIES OF IRON IONS IN THE 3B2O3·KF GLASS MATRIX

2004 ◽  
Vol 18 (10n11) ◽  
pp. 1525-1535 ◽  
Author(s):  
I. ARDELEAN ◽  
P. PASCUTA
Keyword(s):  
Magnetic Susceptibility ◽  
Iron Content ◽  
Glass Matrix ◽  
Structural Changes ◽  
Magnetic Measurement ◽  
Measurement Data ◽  
Ionic Species ◽  
Iron Ions ◽  
Simultaneous Presence ◽  
Valence States

Glasses of the x Fe 2 O 3·(100–x)[3 B 2 O 3· KF ] system, with 0<x≤35 mol %, were investigated by means of EPR and magnetic susceptibility measurements. When increasing the iron content the EPR absorption spectra undergo modification reflecting structural changes of the glass matrix and also the distribution and valence states of iron ions. The magnetic measurement data pointed out the character of interaction involving iron ions as depending on concentration and the simultaneous presence of both Fe 3+ and Fe 2+ ionic species.

EPR AND MAGNETIC SUSCEPTIBILITY STUDIES OF COPPER IONS IN THE 2B2O3·Ag2O GLASS MATRIX

2004 ◽  
Vol 18 (20n21) ◽  
pp. 2915-2921 ◽  
Author(s):  
R. CICEO LUCACEL ◽  
I. ARDELEAN
Keyword(s):  
Magnetic Susceptibility ◽  
Glass Matrix ◽  
Magnetic Measurements ◽  
Copper Ions ◽  
Gradual Increase ◽  
Glass Structure ◽  
Ionic Species ◽  
Magnetic Interactions ◽  
Simultaneous Presence ◽  
Distorted Octahedral

Glasses of the x CuO ·(100-x)[2 B 2 O 3· Ag 2 O ] system, with 0<x≤30 mol %, were investigated by means of EPR and magnetic susceptibility measurements. The influence of a gradual increase in CuO content on the glass structure and magnetic interactions that involved copper ions, have been discussed. EPR absorption spectra show Cu 2+ ions in axially distorted octahedral environments. Both EPR and magnetic measurements data pointed out the simultaneous presence in the glasses with x>5 mol % of Cu 2+ and Cu + ionic species. The Curie behavior of magnetic susceptibility indicates the absence of the superexchange interactions in these glasses.

Chromium(III) Complexes with Some Optically Active α-Hydroxy Acids

1993 ◽  
Vol 48 (3) ◽  
pp. 282-286 ◽  
Author(s):  
M. S. El-Shahawi ◽  
A. A. El-Bindary
Keyword(s):  
Magnetic Susceptibility ◽  
Local Symmetry ◽  
Optically Active ◽  
Octahedral Symmetry ◽  
Hydroxy Acids ◽  
Susceptibility Data ◽  
Pyridine Nitrogen ◽  
Distorted Octahedral ◽  
Cotton Effects ◽  
Two Peaks

Complexes obtained from CrCl3Py3 with some optically active α-hydroxy acids have been characterized by elemental analysis, magnetic susceptibility, vibrational (IR), electronic and circular dichroism (CD) spectra. The magnetic susceptibility data are close to the spin-only value for a d3 chromium(III) ion in octahedral or distorted octahedral symmetry. Three (Cr—Cl) vibrational modes in the region 410-290 cm-1 are observed for some of the complexes indicating C2ν, local symmetry of ligand atoms around the chromium(III). In the electronic spectra two peaks are observed in the range 16949-18018 and 22986-24570 cm-1. They are assigned to d—d transitions in pseudo octahedral symmetry. The structure of the complexes is likely to be facial since strong and well defined Cotton effects are observed. The parameters (Dq, B, β35) for the complexes provide reassurance that pyridine nitrogen is preserved.

MAGNETIC BEHAVIOR OF IRON IONS IN THE P2O5·CaO GLASS MATRIX

2003 ◽  
Vol 17 (24) ◽  
pp. 1271-1275 ◽  
Author(s):  
I. ARDELEAN ◽  
C. ANDRONACHE ◽  
P. PǍŞCUŢǍ
Keyword(s):  
Magnetic Susceptibility ◽  
High Temperature ◽  
Magnetic Moment ◽  
Glass Matrix ◽  
Magnetic Behavior ◽  
Iron Ions ◽  
Ion Content ◽  
Dipole Interactions ◽  
Valence States ◽  
Temperature Susceptibility

The temperature dependence of the magnetic susceptibility of x Fe 2 O 3·(100-x)-[ P 2 O 5· CaO ] glasses with 0<x≤50 mol % have been investigated. These data revealed that the valence states and the distribution of iron ions in the glass matrix depend on the Fe 2 O 3 content. For the glasses with x≤1 mol % only Fe 3+ ions are evidenced. In the case of the glasses with 3≤x≤35 mol % both Fe 3+ and Fe 2 ions co-exist in the P 2 O 5· CaO glass matrix, the Fe 2+ ion content is higher than that of the Fe 3+ ions for glasses with x≥10 mol %. For the glasses with x>35 mol %, the evaluated values of the μ eff indicate either the presence of Fe + ions or the coordination influence on the magnetic moment of iron ions, but the presence of small quantities of the antiferromagnetic or ferrimagnetic interactions between iron ions in studied temperature range cannot be excluded. The high temperature susceptibility results indicate that the iron ions are isolated or participate in dipole-dipole interactions for glasses with x≤35 mol % and are antiferromagnetically coupled for higher contents of Fe 2 O 3.

Studies of Distorted Octahedral Complexes of Cobalt, Nickel and Copper and Their Antibacterial Properties

2018 ◽  
Vol 34 (4) ◽  
pp. 1937-1944 ◽  
Author(s):  
Vijay Kumar ◽  
Rajiv Kumar Singh ◽  
Veena Kumari ◽  
Birendra Kumar ◽  
Shivadhar Sharma
Keyword(s):  
Magnetic Moment ◽  
Electronic Spectra ◽  
Antibacterial Properties ◽  
Octahedral Geometry ◽  
Azomethine Nitrogen ◽  
Distorted Octahedral Geometry ◽  
Octahedral Symmetry ◽  
Orbital Contribution ◽  
Distorted Octahedral ◽  
Crystal Field Parameters

The ligand, 3-hydroxy-4-methoxybenzaldehydethiosemicarbazone has been prepared by the condensation of 3-hydroxy-4-methoxybenzaldehyde and thiosemicarbazide. With the help of this ligand the complexes of Co(II), Ni(II) and Cu(II) have been prepared with general formula [ML2X2] where X is secondary ligand, Cl–, NO3– and CH3COO–. The composition of complexes has been established by their microanalysis, while the metal contents have been determined gravimetrically and volumetrically. On the basis of IR spectra, the coordinating mode of ligand has been determined and has been found to have coordinated through azomethine nitrogen and thione sulphur. The magnetic moment of Co(II) complexes has been found between 4.96-4.72 B. M. The value is slightly higher than the μs value corresponding to three unpaired electrons (3.872 B.M). The increase in value may be attributed to orbital contribution from 4T1g ground state cubic term. The appearance of four bands in their electronic spectra is indicative of tetragonally distorted octahedral geometry of Co(II) complexes. The magnetic moment (3.20-3.30 B. M.) and appearance of 4 bands in the electronic spectra of Ni(II) complexes confirms the distorted octahedral geometry of the complexes. The magnetic moment of Cu(II) complexes has been determined to be (1.95-2.20 B. M.) which shows that Cu(II) complexes are magnetically dilute complexes. The appearance of three bands in their electronic spectra confirms John - Tellor distortion in octahedral symmetry of Cu(II) complexes. The various crystal field parameters exhibiting tetragonal distortion in the octahedral symmetry have also been derived. The positive value of Dt predicts tetragonal elongation in Oh symmetry.

scholarly journals Manganese Fluorene Phosphonates: Formation of Isolated Chains

Inorganics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 92 ◽  
Author(s):  
Clarisse Bloyet ◽  
Jean-Michel Rueff ◽  
Vincent Caignaert ◽  
Bernard Raveau ◽  
Jean-François Lohier ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Hydrogen Bonds ◽  
Phosphonic Acid ◽  
Van Der Waals ◽  
Exchange Interactions ◽  
Van Der Waals Interactions ◽  
Antiferromagnetic Exchange ◽  
Hydrothermal Conditions ◽  
Hirshfeld Surfaces ◽  
Nitrate Tetrahydrate

9,9-dimethylfluorenyl-2-phosphonic acid 1 was reacted with manganese nitrate tetrahydrate to produce under hydrothermal conditions the crystalline manganese phosphonate Mn(H2O)2[O2(OH)PC15H13]2·2H2O which crystallize in the P21/c space group. This compound is a rare example of Mn-phosphonate material featuring isolated chains. The interactions between these chains containing the 9,9-dimethylfluorenyl moieties, result from Van der Waals interactions involving the fluorene ligands and C···H–C hydrogen bonds as revealed by Hirshfeld Surfaces. This material features antiferromagnetic exchange interactions as revealed by the magnetic susceptibility as a function of the temperature.

scholarly journals Synthesis, Spectral Characterization and Biological Activity of Metal(II) Complexes of 2,4,5-Trimethoxybenzaldehyde-S-Benzyldithiocarbazone

2019 ◽  
Vol 32 (1) ◽  
pp. 209-214
Author(s):  
Deepak Kumar ◽  
Arun Kumar Singh ◽  
Ajay Kumar ◽  
Dayanand Prasad ◽  
Vijay Kumar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Metal Complexes ◽  
Metal Ion ◽  
Free Ligand ◽  
Azomethine Nitrogen ◽  
Octahedral Symmetry ◽  
Spectral Bands ◽  
Distorted Octahedral ◽  
And Staphylococcus Aureus

2,4,5-Trimethoxybenzaldehyde was condensed with S-benzyldithiocarbazate to give Schiff base 2,4,5-trimethoxy benzaldehyde-S-benzyldithiocarbazone (BBTC), which was used for complexation with Mn(II), Fe(II) and Co(II) metal ions. The complexes were formulated as M(BBTC)2X2 where X is Cl−, NO3− and CH3COO−. The FTIR spectra of the metal complexes in comparison to that of free ligand suggested the coordination through azomethine nitrogen and thion sulphur forming six membered chelating with metal ion. The magnetic susceptibility and electronic spectral bands revealed octahedral symmetry (Oh) around Mn(II) but tetragonally distorted octahedral symmetry (D4h) of Fe(II) and Co(II) complexes. The positive value of Dt for Fe(II) (68.42-135.2 cm-1) and Co(II) (263-280 cm-1) clearly indicated elongation along z-axis in these complexes which was also supported by the less value of Dq(z) than Dq(xy) for the metal complexes. The ligand as well as its metal complexes have been found active against the bacteria Escherichia coli and Staphylococcus aureus, and antibacterial activity of the free ligand has been observed to have enhanced in metal complexes.

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