Models for the Interaction of Nitrogen with Transition Metals. Part III. Preparation and Properties of some Cationic Arylazo Complexes of Iron

1973 ◽  
Vol 51 (11) ◽  
pp. 1697-1703 ◽  
Author(s):  
D. R. Fisher ◽  
D. Sutton
Keyword(s):  
Transition Metals ◽  
Quadrupole Splitting ◽  
Catalytic Hydrogenation ◽  
Mössbauer Spectra ◽  
Complex Cation ◽  
Isotopic Substitution ◽  
Spectroscopic Measurements ◽  
Mossbauer Spectra ◽  
Strong Band ◽  
Azo Group

Fe(CO)3(PPh3)2 reacts with p-substituted aryl diazonium tetrafluoroborates to yield the compounds [Fe(CO)2(PPh3)2(N2C6H4X)]BF4 (where X = F, Cl, Br, H, NO2, OCH3, and OH but not NEt2). The complex cation displays properties consistent with replacement of an equatorial CO ligand in Fe(CO)3(PPh3)2 by the more effective π-acceptor ligand [N2C6H4X]+ analogous to NO+. A very strong band at ca. 1720 cm−1 in the i.r. spectrum due to v(N2) has been identified by 15N isotopic substitution. This value is much higher than for most other arylazo complexes yet prepared and the azo group resists catalytic hydrogenation. A number of spectroscopic measurements are reported, including unusually small quadrupole splitting effects in the Mössbauer spectra.

Dithiolium and diselenolium compounds of the transition metals

1969 ◽  
Vol 22 (1) ◽  
pp. 83 ◽  
Author(s):  
RL Martin ◽  
IM Stewart
Keyword(s):  
Transition Metals ◽  
Temperature Dependence ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra ◽  
First Time

The preparations are reported of an extended series of compounds of the type ML2X4 where M is Mn, Fe, Co, or Ni; X is Cl or Br; and L is analytically identical with dithioacetylacetone. ��� Electronic, infrared, and Mossbauer spectra together with the temperature dependence of the magnetism (80-300�K) of these compounds establish-contrary to previous suggestions in the literature-that they should be properly formulated as tetrahalometallate salts of the 3,5- dimethyl-1,2-dithiolium cation. Simple salts of this cation (such as the iodide) have also been isolated. ��� During the course of this work salts (I- and [CoCl4]2-) of the hitherto unknown 3,5-dimethyl-1,2-diselenolium ion were synthesized and characterized for the first time.

The Mössbauer spectra of hydroxycarbonate green rusts

Clay Minerals ◽  
1984 ◽  
Vol 19 (1) ◽  
pp. 77-83 ◽  
Author(s):  
E. Murad ◽  
R. M. Taylor
Keyword(s):  
Quadrupole Splitting ◽  
Mössbauer Spectra ◽  
Paramagnetic State ◽  
Type Structure ◽  
Natural Systems ◽  
Mossbauer Spectra ◽  
Green Rusts ◽  
Cation Arrangement ◽  
Excess Fe

AbstractMössbauer spectra of Fe2+Fe3+ and Fe2+Al hydroxycarbonates taken in the paramagnetic state were fitted using two Fe2+ and Fe3+ doublets each. These spectra can be interpreted in terms of an ordered cation arrangement in the pyroaurite-type structure. The inner Fe2+ doublet seems to be the outcome of excess Fe3+ in the samples studied. The outer Fe2+ doublet (quadrupole splitting ∼2·8 mm s−1, FWHM = 0·26 mm s−1) is relatively well-defined and can, together with the fact that this doublet disappears on oxidation, possibly serve to identify these compounds in natural systems.

119Sn Mössbauer spectroscopy of solvothermally synthesized fluorides ASnF3 (A = Na, K, Rb, Cs)

2015 ◽  
Vol 70 (10) ◽  
pp. 765-767
Author(s):  
Birgit Gerke ◽  
Thanh Thao Tran ◽  
Rainer Pöttgen ◽  
P. Shiv Halasyamani
Keyword(s):  
Mössbauer Spectroscopy ◽  
Quadrupole Splitting ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Lone Pair ◽  
Electric Quadrupole ◽  
119Sn Mössbauer Spectroscopy ◽  
Solvothermal Route ◽  
Mossbauer Spectra ◽  
Divalent Tin

AbstractThe complex Sn(II) fluorides ASnF3 (A = Na, K, Rb, Cs) were synthesized from the alkali fluorides and SnF2 in methanol through a solvothermal route. Their 119Sn Mössbauer spectra manifest divalent tin. The isomer shifts range from 3.09 to 2.94 mm s–1. The pronounced lone-pair character at the Sn(II) centres is expressed by strong electric quadrupole splitting (1.91–1.95 mm s–1). The two, respectively four crystallographically independent tin sites in NaSnF3, KSnF3 and RbSnF3 could not be resolved in the 119Sn spectra.

Hyperfine quadrupole splitting and mössbauer spectra for an orbital doublet

1973 ◽  
Vol 59 (2) ◽  
pp. 707-714 ◽  
Author(s):  
I. B. Bersuker ◽  
S. A. Borshch ◽  
I. Ya. Ogurtsov
Keyword(s):  
Quadrupole Splitting ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra

Mössbauer studies in transition metal chemistry. IV. Iron(II) complexes of 2-(2'-Pyridyl)benzimidazole

1978 ◽  
Vol 31 (3) ◽  
pp. 487 ◽  
Author(s):  
RL Martin ◽  
IAG Roos ◽  
DML Goodgame ◽  
AASC Machado
Keyword(s):  
Temperature Dependence ◽  
Mössbauer Spectra ◽  
Spin Crossover ◽  
Complex Cation ◽  
Octahedral Symmetry ◽  
Line Lattice ◽  
Metal Chemistry ◽  
Mossbauer Spectra ◽  
Iv Iron ◽  
Mössbauer Parameters

Mossbauer spectra of a number of compounds containing the [Fe(pyb)3]2+ complex cation [pyb, 2-(2'-pyridyl)benzimidazole] confirm that these compounds undergo a change of spin state with temperature consistent with a 5T2-1A1 spin crossover. The nature of the Mossbauer spectra and their temperature-dependence are sensitive to the associated anion and the method of preparation. ��� The temperature-dependence of the Mossbauer parameters has been used to derive information about the distortions from octahedral symmetry and it is concluded that the dimensions of the crystal-line lattice are changing slightly with temperature.

M÷ssbauer studies in transition metal chemistry. I. Compounds of iron with Dithioacetylacetone (Pentane-2,4-dithione)

1971 ◽  
Vol 24 (11) ◽  
pp. 2231 ◽  
Author(s):  
RL Martin ◽  
IAG Roos
Keyword(s):  
Transition Metal ◽  
Temperature Dependence ◽  
Quadrupole Splitting ◽  
Ground State ◽  
Mössbauer Spectra ◽  
Transition Metal Chemistry ◽  
Temperature Dependent ◽  
Orbital Degeneracy ◽  
Metal Chemistry ◽  
Mossbauer Spectra

The temperature dependence of the Mossbauer spectra of some iron- containing compounds of dithioacetylacetone are reported between 4 and 293 K. ��� The quadrupole splitting ΔEq of [Fe(SacSac)3] is larger than usually observed for low-spin six-coordinated iron(III) and is ascribed to the lifting of orbital degeneracy of the 2T2 ground state by small axial and rhombic distortions. ��� The unsubstituted and phenyl-substituted dithiolium salts of [FeCl4]2- exhibit strongly temperature-dependent quadrupole splittings, which arise directly from the lifting of the orbital degeneracy of the 5E ground state due to distortion of the [FeCl4]2- tetrahedron.

scholarly journals Variation of Quadrupole Splitting in Modified Oxyhemoglobin: A Mössbauer Effect Study

2000 ◽  
Vol 55 (1-2) ◽  
pp. 193-198 ◽  
Author(s):  
M. I. Oshtrakh ◽  
O. B. Milder ◽  
V. A. Semionkin ◽  
A. L. Berkovsky ◽  
M. A. Azhigirova ◽  
...  
Keyword(s):  
Quadrupole Splitting ◽  
Mössbauer Spectra ◽  
Effect Study ◽  
Heme Iron ◽  
Mossbauer Effect ◽  
Frozen Solution ◽  
Mossbauer Spectra ◽  
Human Adult ◽  
Adult Hemoglobin ◽  
Α And Β Subunits

Human adult hemoglobin modified by both pyridoxal-5'-phosphate and glutaraldehyde in the oxy-form was studied by Mössbauer spectroscopy. Mössbauer spectra were measured at 87 and 295 K (hemoglobin in lyophilized form) and at 87 K (hemoglobin in frozen solution). The values of the quadrupole splitting for modified oxyhemoglobin were found to be lower then those of oxyhemoglobin without modifications in lyophilized form and frozen solution, respectively. The Mössbauer spectra of modified oxyhemoglobin were also analyzed in terms of the heme iron inequivalence in α-and β-subunits of the tetramer. Differences of the tendencies of temperature dependencies of quadrupole splitting for modified and non-modified oxyhemoglobin in lyophilized form were shown.

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