Temperature-dependent magnetic moments of Fe(III) complexes with high-spin–low-spin transitions

1993 ◽  
Vol 47 (9) ◽  
pp. 5455-5458 ◽  
Author(s):  
Kuang Xiao-Yu ◽  
Irène Morgenstern-Badarau ◽  
Isabelle Malfant
Keyword(s):  
High Spin ◽  
Magnetic Moments ◽  
Temperature Dependent ◽  
Spin Transitions

The effect of the lattice expansion on high spin ⇌ low spin transitions

1982 ◽  
Vol 68 (1-2) ◽  
pp. 65-71 ◽  
Author(s):  
H. Spiering ◽  
E. Meissner ◽  
H. Köppen ◽  
E.W. Müller ◽  
P. Gütlich
Keyword(s):  
High Spin ◽  
Lattice Expansion ◽  
Spin Transitions

Solute-Solvent Interactions and High Spin ⇌ Low Spin Transitions in Ferric Dithiocarbamates

1985 ◽  
Vol 40 (1) ◽  
pp. 79-83
Author(s):  
P. Ganguli
Keyword(s):  
High Spin ◽  
Alkyl Chain ◽  
Preferential Solvation ◽  
Solvent Interactions ◽  
Spin Transitions

The HS ⇌ LS transition in ferric dithiocarbamates in a number of solvents has been investigated using NMR and is interpreted in terms of preferential solvation or second co-ordination sphere reorganisation effects. These studies clearly demonstrate that neglect of pseudo contact shifts can lead to erroneous conclusions about the spin delocalisation mechanisms. The spin derealization in these systems is by direct σ-delocalization along the alkyl chain. The As values of 2T2 and 6A1 states have the same sign.

Quaternary intermetallics RE2Pt3Ga4In (RE=Y, Gd-Tm) – intergrowth structures of NdRh2Sn4 and TiNiSi related slabs

2020 ◽  
Vol 235 (4-5) ◽  
pp. 117-125
Author(s):  
Myroslava Horiacha ◽  
Maximilian K. Reimann ◽  
Jutta Kösters ◽  
Vasyl‘ I. Zaremba ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystals ◽  
High Frequency ◽  
Magnetic Moments ◽  
Intermetallic Phases ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Arc Melting ◽  
Intergrowth Structures ◽  
A Site

AbstractThe quaternary gallium-rich intermetallic phases RE2Pt3Ga4In with RE = Y and Gd-Tm were synthesized by arc-melting of the elements and subsequent annealing. Small single crystals were obtained by high-frequency annealing of the samples in sealed tantalum ampoules. The polycrystalline samples were characterized through their X-ray powder patterns. The RE2Pt3Ga4In phases crystallize with a site ordering variant of the orthorhombic Y2Rh3Sn5 type, space group Cmc 21. The structures of Gd2Pt3Ga4In, Dy2Pt3Ga4.14In0.86, Er2Pt3Ga4.17In0.83 and Tm2Pt3Ga4.21In0.79 were refined from single-crystal X-ray diffraction data. The single crystals reveal small homogeneity ranges RE2Pt3Ga4±xIn1±x. The striking geometrical structural building units are slightly distorted trigonal prisms around the three crystallographically independent platinum atoms: Pt1@RE4Ga2, Pt2@RE2Ga4 and Pt3@RE2Ga2In2. Based on these prismatic building units, the RE2Pt3Ga4In structures can be described as intergrowth variants of TiNiSi and NdRh2Sn4 related structural slabs. Temperature dependent magnetic susceptibility studies of Gd2Pt3Ga4In and Tb2Pt3Ga4In show Curie-Weiss behavior and the experimental magnetic moments confirm stable trivalent gadolinium respectively terbium. Gd2Pt3Ga4In and Tb2Pt3Ga4In order antiferromagnetically at TN = 15.8(1) and 26.0(1) K. Magnetization curves at 3 K show field-induced spin reorientations.

Ternary Indides REMgIn (RE = Y, La–Nd, Sm, Gd–Tm, Lu). Synthesis, Structure and Magnetic Properties

2004 ◽  
Vol 59 (5) ◽  
pp. 513-518 ◽  
Author(s):  
Rainer Kraft ◽  
Martin Valldor ◽  
Daniel Kurowski ◽  
Rolf-Dieter Hoffmann ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Moments ◽  
Three Dimensional ◽  
Temperature Dependent ◽  
Variable Parameters ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Sample Chamber ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

Abstract The equiatomic rare earth-magnesium-indium compounds REMgIn (RE = Y, La-Nd, Sm, Gd- Tm, Lu) were prepared from the elements in sealed tantalum tubes inside a water-cooled sample chamber of an induction furnace. All compounds were characterized through their X-ray powder patterns. They crystallize with the hexagonal ZrNiAl type structure, space group P6̄̄2m, with three formula units per cell. The structure of SmMgIn was refined from X-ray single crystal diffractometer data: a = 761.3(2), c = 470.3(1) pm, wR2 = 0.0429, 380 F2 values and 14 variable parameters. The DyMgIn, HoMgIn, and TmMgIn structures have been analyzed using the Rietveld technique. The REMgIn structures contain two cystallographically independent indium sites, both with tri-capped trigonal prismatic coordination: In1Sm6Mg3 and In2Mg6Sm3. Together the magnesium and indium atoms form a three-dimensional [MgIn] network with Mg-Mg distances of 320 and Mg-In distances in the range 294 - 299 pm. Temperature dependent magnetic susceptibility data show Curie-Weiss behavior for DyMgIn, HoMgIn, and TmMgIn with experimental magnetic moments of 11.0(1) μB/Dy atom, 10.9(1) μB/Ho atom, and 7.5(1) μB/Tm atom. The three compounds order antiferromagnetically at TN = 22(2) K (DyMgIn), 12(1) K (HoMgIn), and 3(1) K (TmMgIn).

scholarly journals Notizen: Nitroxylradikal-Metallkomplexe / Nitroxyl Radical Metal Complexes

1976 ◽  
Vol 31 (2) ◽  
pp. 208-216 ◽  
Author(s):  
Rudolf Weissgerber ◽  
Karl E. Schwarzhans
Keyword(s):  
Free Radicals ◽  
Metal Ions ◽  
Metal Complexes ◽  
Nitroxyl Radical ◽  
Magnetic Moments ◽  
Epr Spectra ◽  
Temperature Dependent ◽  
Stable Free Radicals ◽  
Dependent Interaction

A series of complexes formed between metal ions and the stable free radicals 3-carboxy-2,2,5,5-tetramethylpyrroline-1-oxyl, 3-carboxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl and glyoxal-bis(2,2,6,6-tetramethyl-4-iminopiperidine-1-oxyl) has been prepared. The magnetic moments and the EPR spectra of the complexes and the free ligands have been investigated. Some of the complexes show a temperature dependent interaction between the radicalic groups of the ligands.

Intermetallic Cadmium Compounds M5T2Cd (M = Ca, Yb, Eu; T = Cu, Ag, Au) with Mo5B2Si-type Structure

2011 ◽  
Vol 66 (12) ◽  
pp. 1219-1224
Author(s):  
Frank Tappe ◽  
Christian Schwickert ◽  
Matthias Eul ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Moments ◽  
Small Degree ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Pauli Paramagnetism ◽  
Slab Temperature ◽  
Experimental Magnetic Moment ◽  
The Eu

The intermetallic compounds M5T2Cd (M = Ca, Yb, Eu; T = Cu, Ag, Au) and Yb5Cu2Zn were synthesized by melting the elements in sealed tantalum tubes followed by annealing at 923 K. All phases were characterized on the basis of powder and single-crystal X-ray diffraction data: Mo5B2Si type, I4/mcm, Z = 4, a = 828.7(1), c = 1528.1(3) pm, wR2 = 0.030, 440 F2 values, 16 variables for Eu5Cu2Cd, a = 788.2(1), c = 1459.3(5) pm, wR2 = 0.053, 378 F2 values, 16 variables for Yb5Cu2Cd, and a = 797.2(1), c = 1438.8(3) pm, wR2 = 0.036, 386 F2 values, 17 variables for Yb5Au2.19Cd0.81, which shows a small degree of Au / Cd mixing. The M5T2Cd structures are intergrowth variants of slightly distorted CuAl2- and U3Si2-related slabs. Striking coordination motifs (exemplary for Eu5Cu2Cd) are square antiprisms of the Eu atoms around Cd, Eu8 square prisms around Eu, and trigonal Eu6 prisms around Cu within the AlB2-related slab. Temperature-dependent magnetic susceptibility measurements showed Pauli paramagnetism for Yb5Cu2Zn, indicating purely divalent ytterbium. Eu5Au2Cd exhibits Curie-Weiss behavior above 100 K with an experimental magnetic moment of 8.14 μB per Eu atom and a Weiss constant of 56 K. Antiferromagnetic ordering of the EuII magnetic moments is evident at 36 K, and a metamagnetic transition is observed at 25 K and 13 kOe.

Polyamine ligands. I. The stereochemistry of transition metal complexes with the ligand 1,8-Bis(2'-pyridyl)-3,6-diazaoctane

1970 ◽  
Vol 23 (3) ◽  
pp. 491 ◽  
Author(s):  
AT Phillip ◽  
AT Casey ◽  
CR Thompson
Keyword(s):  
Transition Metal Complexes ◽  
Metal Ion ◽  
Electronic Absorption Spectra ◽  
Magnetic Moments ◽  
Temperature Dependent ◽  
Physical Measurements ◽  
Square Planar ◽  
First Time ◽  
Perchlorate Complex ◽  
Complex Ion

The new polyamine ligand 1,8-bis(2'-pyridyl)-3,6-diazaoctane has been synthesized for the first time by the reaction between 2-vinylpyridine and ethyl-enediamine. The ligand could not be distilled without decomposition and hence it was purified by converting it into the crystalline copper(11) perchlorate complex, from which the ligand was liberated by the reaction with sodium sulphide solution. The pure ligand was obtained in an overall yield of 28%, based on starting materials. The complexes formed by the ligand with the metal ions copper(11), nicke1(11), palladium(11), zinc(11), and cobalt(111) were isolated and characterized by physical measurements of their conductance in solution, magnetic moments, infrared and electronic absorption spectra. The ligand adopts the planar-N4 configuration around the metal ion in the complexes with copper(11), nicke1(11), and palladiurn(11), whereas it probably adopt's a tetrahedral-N4 configuration around the zinc(11) complex ion. The nickel(11) perchlorate complex is diamagnetic in the solid state and it most likely contains the metal ion in square-planar cordination. When dissolved in coordinating solvents, this complex undergoes a reversible, temperature-dependent equilibrium between diamagnetic and solvated, paramagnetic forms.

Ternary indides RE3T2In4 (RE=Dy–Tm; T=Pd, Ir)

2018 ◽  
Vol 73 (11) ◽  
pp. 765-772 ◽  
Author(s):  
Sebastian Stein ◽  
Lukas Heletta ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Transition Metal ◽  
Magnetic Moments ◽  
Hexagonal Structure ◽  
Temperature Dependent ◽  
X Ray ◽  
Wyckoff Position ◽  
Different Types ◽  
High Temperature Reactions

AbstractThe ternary rare earth transition metal-indides RE3T2In4 (RE=Dy–Tm; T=Pd, Ir) were obtained from high-temperature reactions in sealed niobium ampoules. These indides adopt a hexagonal structure of the Lu3Co1.87In4 type (space group P6̅), a ternary ordered superstructure of the aristotype Fe2P. The structures of three different compounds were refined from single-crystal X-ray diffractometer data: a=768.20(6), c=381.97(3) pm, 1441 F2 values, 24 parameters, wR2=0.0338 (Ho3Pd1.90In4); a=774.98(3), c=378.51(2) pm, 577 F2 values, 23 parameters, wR2=0.0742 (Ho3Ir1.69In4.31) and a=780.3(1), c=369.4(1) pm, 573 F2 values, 22 parameters, wR2=0.0403 (Tm3Ir1.51In4.49). Refinements of the occupancies revealed homogeneity ranges in case of the iridium-based crystals resulting from Ir/In mixing. The refined composition of the palladium compound was Ho3Pd1.90In4 resulting from defects on the Wyckoff position 1d, which was already reported for the prototype Lu3Co1.87In4. The geometrical motifs of the RE3T2In4 structures are three different types of tricapped trigonal prisms around the transition metal and indium atoms which are condensed via common edges and triangular faces. Temperature dependent magnetic susceptibility measurements of Dy3Ir2In4 and Tm3Ir2In4 showed Curie-Weiss behavior and the experimental magnetic moments of 10.59(2) μB (Dy3Ir2In4) and 7.40(2) μB (Tm3Ir2In4) confirming stable trivalent RE3+ states. Dy3Ir2In4 and Tm3Ir2In4 order antiferromagnetically with Néel temperatures of TN=13.6(5) and 5.4(5) K, respectively.

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