Mössbauer-Spektroskopische Untersuchungen an der high/low spin Eisen(II)-Verbindung Cs2FeHFeL(CN)6 / Mössbauer Spectroscopic Investigation of the High/Low Spin Iron(II) Compound Cs2FeHFeL(CN)6

1977 ◽  
Vol 32 (9) ◽  
pp. 992-997 ◽  
Author(s):  
W. D. Griebler ◽  
J. Pebler ◽  
K. Schmidt ◽  
D. Babel
Keyword(s):  
Magnetic Susceptibility ◽  
Low Temperature ◽  
Ir Spectra ◽  
High Spin ◽  
Spectroscopic Investigation ◽  
Ir Absorption ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion ◽  
High Spin Iron

By Mössbauer spectroscopy the cubic compound CsFe(CN)3, α = 5.208 Å, is shown to contain high and low spin iron(II) in 1:1 proportion independant of temperature 4.2 ≦ T ≦ 600 K. This gives evidence of isomorphism with the elpasolite Cs2MgFe(CN)6. The quadrupol splitting of the high spin iron(II) spectra strongly depends on temperature and vanishes beyond 400 K. This behaviour is interpreted in terms of static Jahn Teller distortion in the low temperature range, also indicated by the splitting of the IR absorption associated with the Fe-N stretching frequency.The data of Mössbauer and IR spectra, as well as of magnetic susceptibility measurements are given and discussed.

N-Substituted salicylaldimine complexes of manganese(III). Synthesis, magnetism, and spectra

1969 ◽  
Vol 22 (1) ◽  
pp. 39 ◽  
Author(s):  
A van den Bergen ◽  
KS Murray ◽  
MJ O'Conner ◽  
BO West
Keyword(s):  
High Spin ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Magnetic Behaviour ◽  
Teller Distortion ◽  
Small Deviations ◽  
Near Infrared Spectra ◽  
Jahn Teller ◽  
Jahn Teller Distortion

Complexes of manganese(III) and N-substituted salicylaldimines have been prepared of general formulae Mn(sal-NR)3 and Nn(sal-NR)2X (X = Cl, Br, OAc). The complexes show high-spin magnetic behaviour with small deviations of the susceptibilities from the Curie law. Complexes of the type Mn(salen)X(X = Br, I) have also been studied and these show somewhat larger deviations from Curie behaviour. It is difficult to interpret this Curie-Weiss behaviour with certainty, but it can be explained for the salen derivatives, in particular, in terms of very weak antiferromagnetic interactions. The visible and near-infrared spectra for all the complexes are assigned. A Jahn-Teller splitting of the d-d transition is observed. Comparison of the i.r. spectra of the M(sal)3 derivatives (M = CrIII, MnIII, and FeIII) in the region 700-250 cm-1 has enabled assignments of the v(M-O) modes to be made. The spectra suggest that a Jahn-Teller distortion is operative in the Mn(sal)3 complex.

Structure of the clinopyroxene-type compound CaCuGe2O6 between 15 and 800 K

2005 ◽  
Vol 61 (4) ◽  
pp. 367-380 ◽  
Author(s):  
Günther J. Redhammer ◽  
Gerold Tippelt ◽  
Michael Merz ◽  
Georg Roth ◽  
Werner Treutmann ◽  
...  
Keyword(s):  
Phase Transition ◽  
Magnetic Susceptibility ◽  
Magnetic Phase ◽  
Metal Layer ◽  
Lattice Parameters ◽  
Zigzag Chain ◽  
Two Dimensional ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion

CaCuGe2O6 shows a strongly distorted clinopyroxene-type structure with P21/c symmetry at 298 K. The Cu2+ ion at the M1 site is coordinated by six O atoms forming an octahedron, which deviates significantly from ideal geometry. Individual M1 sites are connected via common edges to form an infinite zigzag chain parallel to the crystallographic c axis. The Ca2+ ion at M2 shows a sevenfold coordination. M2 sites are connected to the M1 chain via three common edges, thereby forming a metal layer within the bc plane. Besides the strong Jahn–Teller distortion of the Cu site, the structure of the title compound differs from `normal' clinopyroxenes by a distortion of alternate layers of Ge sites. While the Ge(A) site is fourfold coordinated by O atoms, forming infinite chains of corner-sharing chains parallel to the c axis, the Ge(B) site exhibits a fivefold coordination, thereby forming a true two-dimensional layer of edge-sharing GeO5 bipyramids. Decreasing the temperature causes a magnetic phase transition at 40 K, as monitored by a broad maximum in the magnetic susceptibility and by discontinuities in the lattice parameters. Increasing the temperature causes variations in bond lengths, edge lengths and bond angles. Most prominent is the increase of one bond length of the Ge(B) site and the increase of the tetrahedral bridging angle of the Ge(A) site. At 660 K a crystallographic phase transition is observed where the symmetry changes from P21/c to C2/c. The transition is accompanied by large changes in the lattice parameters which are indicative of distinct topological changes of several structural building units. The high-temperature C2/c structure is similar to that of the germanate clinopyroxene CaMgGe2O6.

scholarly journals Unexpected Spin-Crossover and a Low-Pressure Phase Change in an Iron(II)/Dipyrazolylpyridine Complex Exhibiting a High-Spin Jahn–Teller Distortion

2015 ◽  
Vol 54 (13) ◽  
pp. 6319-6330 ◽  
Author(s):  
Laurence J. Kershaw Cook ◽  
Flora L. Thorp-Greenwood ◽  
Tim P. Comyn ◽  
Oscar Cespedes ◽  
Guillaume Chastanet ◽  
...  
Keyword(s):  
Phase Change ◽  
High Spin ◽  
Spin Crossover ◽  
Low Pressure ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion ◽  
Pressure Phase

Structure-Property Relations in xCuO-(1-x)As2O3-0.7B2O3 (0.01≤x≤0.05) Glasses by Magnetic Susceptibility Measurements, IR and EPR Spectroscopy

2006 ◽  
Vol 111 ◽  
pp. 103-106
Author(s):  
B.B. Das ◽  
A. Gopinath
Keyword(s):  
Magnetic Susceptibility ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
Teller Distortion ◽  
Property Relations ◽  
Structure Sensitive ◽  
Jahn Teller ◽  
Linear Fit ◽  
Jahn Teller Distortion

Studies on xCuO-(1-x)As2O3-0.7B2O3(0.01≤x≤0.05) (G1-G5: x = 0.01, 0.02, 0.03, 0.04, 0.05) glasses were done using varieties of structure sensitive techniques. The powder X-ray diffraction (XRD) studies show the formation of glasses in the composition. The IR spectral results show the presence of Cu-O bond, planar [BO3/2] and [BO3 -n](n=1, 2, 3) units and tetrahedral {BO4/2]- units. The magnetic susceptibility results show Curie-Weiss behaviour in the range 4.2-400 K. The calculated values of the exchange integral from the Weiss constant obtained form the linear fit of the Curie-Weiss law are found to be in the range 5.22-29.50 meV. From the trend of the gmatrices of gơ>g⊥>ge (ge =2.0023) obtained from electron paramagnetic resonance (EPR) lineshapes simulation we conclude that the paramagnetic site in these glasses is Cu2+(3d9) which is in a tetragonally elongated octahedron [O1/2-CuO4/2-O1/2] exhibiting Jahn-Teller distortion having D4h symmetry with orbital singlet 3dx2-y2 (2B1g) as the ground state.

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