Search results for "SSB"

Organotin(IV) chloride complexes with phosphocholine and dimyristoyl-L-?-phosphatidylcholine

2000

Several complexes of R n SnCl 4-n (R = Me, Ph, n = 1-3; R = nBu, n = 2, 3) with phosphocholine and dimyristoyl-L-α-phosphatidylcholine (phospholipid) have been synthesized and characterized by means of Mossbauer spectroscopy and NMR. Triorganotin chlorides form complexes of (R 3 SnCl) 2 .L stoichiometry with a trigonal bipyramidal pentacoordinate tin environment, while the others form 1:1 complexes with an octahedral hexacoordinate tin environment, with the ligands coordinating through anionic phosphodiester moieties in all cases.

Crystal structure and mössbauer spectroscopy studies of the ferrimagnetic complex bimetallic salt hexaamminechromium (III) hexachloroferrate (III), […

1992

The crystal and molecular structures of the ferrimagnetic bimetallic complex salt hexaamminechromium(III) hexachloroferrate(III), [Cr(NH3)6][FeCl6], have been determined from single-crystal, three-dimensional x-ray diffraction counter data. The compound crystallizes as orange coloured crystals in the space groupC2/c of the monoclinic system with Z=4 and has cell dimensionsa=11.325(1) A,b=11.387(1) A,c=11.233(1) A, and β=90.83(1)A. The structure was refined by using segmented block diagonal least-squares techniques to discrepancy indices R and Rw of 0.0233 and 0.0285, respectively. The metal ions occupy sites with symmetry $$\bar 1$$ and are nearly octahedrally coordinated. In the [FeCl6]3− …

Reactivity and Structural Defects in Glaserite-Type Iron-Vanadates

2018

Chemical characterization of iron in atmospheric aerosols

1992

Abstract The total Fe content, the soluble fractions of Fe(II) and Fe(III), and several species of Fe were determined in various atmospheric aerosol samples by means of atomic absorption spectrometry, ion chromatography and Mossbauer spectrometry.

An ESCA and Mössbauer study of the oxide layer formed on steel in water containing chromate and chloride ions

1983

Abstract The formation of oxidic layers on steel in chromate solutions was studied by photo-electron and Mossbauer spectroscopy. To simulate more aggressive realistic systems, some chloride ions were added to the solution. The layers formed under these conditions were found to be thicker by an order of magnitude than those formed in the absence of chloride ions. They probably consist of ferric and chromic oxides of the corundum type (Fe 1−2 Cr x ) 2 O 3 , with the Cr : Fe ratio being depth dependent. The oxide layer is subdivided into small regions behaving superparamagnetically. This heterogeneity of the layer is ascribed to the attack by the chloride ions. The structure of the oxides foun…

Towards a revisitation of vesuvianite-group nomenclature: the crystal structure of Ti-rich vesuvianite from Alchuri, Shigar Valley

2016

Vesuvianite containing 5.85 wt% TiO2from an Alpine-cleft-type assemblage outcropped near Alchuri, Shigar Valley, Northern Areas, has been investigated by means of electron microprobe analyses, gas-chromatographic analysis of H2O, X-ray powder diffraction, single-crystal X-ray structure refinement,27Al NMR,57Fe Mössbauer spectroscopy, IR spectroscopy and optical measurements. Tetragonal unit-cell parameters are:a= 15.5326 (2),c= 11.8040 (2) Å, space groupP4/nnc. The structure was refined to finalR1= 0.031,wR2= 0.057 for 11247I> 2σ(I). A general crystal-chemical formula of studied sample can be written as follows (Z= 2):[8–9](Ca17.1Na0.9)[8]Ca1.0[5](Fe2+0.44Fe3+0.34Mg0.22)[6](Al3.59Mg0.41)…

Mössbauer Spectroscopic Evidence of Angle-Dependent Intersystem Crossing in LiNbO3:Fe3+

1986

M\"ossbauer emission spectra of LiNb${\mathrm{O}}_{3}$:$^{57}\mathrm{Co}$ single crystals in magnetic fields up to 5 T at 4.2 K show initial populations of the $^{6}A_{1\mathrm{g}}$ Zeeman substates of ${\mathrm{Fe}}^{3+}$ which depend strongly on the angle between the crystallographic $c$ axis and the magnetic field. This is interpreted in terms of a crystal-field effect on excited states which influences the initial populations of the Zeeman sublevels of the $^{6}A_{1\mathrm{g}}$ ground term after the electron-capture decay of $^{57}\mathrm{Co}$. An intersystem crossing process due to orbit-lattice interaction can fairly well explain the angular dependence.

Pyridazine-Supported Polymeric Cyanometallates with Spin Transitions

2019

Heterometallic cyano-bridged spin-crossover complexes form a large family of switchable compounds with different structural motives and diverse transition characteristics. Here we report on the hysteretic water-dependent spin transitions found in the family of [Fe(pyridazine)2M(CN)4] frameworks (M = Ni, Pd, Pt). The structure of three new spin-crossover compounds is built of cyanometallic layers supported by pyridazine ligands. The frameworks contain water guest molecules that can be removed upon heating. Spin transition was found in both hydrated and dehydrated compounds, while the removal of water stimulated a complete spin state switch. Mössbauer spectroscopy revealed two different …

The effect of low pressure on a high-spin—low-spin transition

1983

Abstract The effect of low pressure ( p = 150 bar) on the high-spin (HS)—low-spin (LS) transition in [Fe x Zn 1− x (2-pic) 3 ]Cl 2 · EtOH ( x = 0.5, 1.0) was measured by Mossbauer spectroscopy and the results compared with theory. The linear dependence of the volume of the lattice on the HS fraction, which is the basic assumption of the theory, was proven by temperature dependent X-ray measurements.

Spin crossover in a tetranuclear Cr(III)-Fe(III)3 complex

2004

A novel heteronuclear exchange-coupled complex [Cr I I I {(CN)Fe I I I -( 5 L)} 3 (CN) 3 ] containing a pentadentate blocking ligand 5 L was synthesized. The X-ray structure shows that a meridional isomer applies with inequivalent Fe I I I centers. The complex exhibits a thermally induced spin crossover along with the exchange coupling. Mossbauer spectra indicate a spin transition between S = ½ and S = 5/2 states although a considerable amount of Fe I I I centers stays high-spin at T = 6 K. The magnetization, the magnetic susceptibility, and the Mossbauer data were fitted in one run with a spin crossover model taking into account exchange interactions among all metal centers.