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.

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.

Temperature dependence of the Mossbauer spectra of several iron(III) trisdithiocarbamate complexes

1990 ◽  
Vol 2 (50) ◽  
pp. 10091-10107 ◽  
Author(s):  
J M Fiddy ◽  
I Hall ◽  
F Grandjean ◽  
G J Long ◽  
U Russo
Keyword(s):  
Temperature Dependence ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra

scholarly journals Verteilung und Valenz der Kationen in Spinellsystemen mit Eisen und Vanadium, III Röntgenographische und Mößbauer-spektroskopische Untersuchung des Spinellsystems ZnFeVO4-Fe3O4 / Distribution and Valence of the Cations in Spinel Systems with Iron and Vanadium, III X-ray Investigation and Mössbauer Spectra of the Spinel System ZnFeVO4-Fe3O4

1981 ◽  
Vol 36 (10) ◽  
pp. 1228-1233 ◽  
Author(s):  
Erwin Riedel ◽  
Hümeyra Anik ◽  
Till Dützmann
Keyword(s):  
Mössbauer Spectra ◽  
X Ray ◽  
Lattice Constants ◽  
Mossbauer Spectra ◽  
Mössbauer Parameters ◽  
Spinel System

Abstract The spinel system Zni_zFe2:[Fei+2;Vi_I]04 has been prepared by heating mixtures of ZnFeV(>4 and Fe3Ü4 at 1000 °C. The lattice constants, the oxygen parameters and the Mössbauer parameters show that a transition from a nearly normal to an inverse distribu-tion of Fe(II) and Fe(III) exists.

Positive Temperature Dependence of Quadrupole Splittings in Mössbauer Spectra of Fe1.33Nb2.67Se10

2002 ◽  
Vol 57 (6-7) ◽  
pp. 627-630 ◽  
Author(s):  
Takashi Suzuki ◽  
Noriaki Okubo
Keyword(s):  
Temperature Dependence ◽  
Mössbauer Effect ◽  
Mössbauer Spectra ◽  
Positive Temperature ◽  
Mossbauer Effect ◽  
Mossbauer Spectra ◽  
Positive Temperature Dependence ◽  
Low Dimensional

The Mössbauer effect in the low-dimensional compound Fe1.33Nb2.67Se10 has been examined between 78 and 414 K. An anusual positive temperature dependence of the quadrupole splittings was found above 250 K. As a possible origin a mechanism due to π bonding is suggested

119Sn Mössbauer Spectra of Sn–Ni Compounds

1975 ◽  
Vol 53 (2) ◽  
pp. 307-310 ◽  
Author(s):  
G. Michael Bancroft ◽  
K. David Butler
Keyword(s):  
Transition Metal ◽  
Mössbauer Spectra ◽  
Solvent Molecule ◽  
Mossbauer Spectra ◽  
Nickel Compounds ◽  
Mössbauer Parameters ◽  
Solvent Molecules

Sn Mössbauer spectra have been recorded for eleven tin-nickel compounds of the type Clx,Sn[NiLCp]4−x (L = CO, PPh3;x = 2,3) and Cl3SnNiL2Cp.S (S = solvent molecule). The center shifts are used to distinguish coordinated SnCl3 and uncoordinated ionic SnCl3−, respectively. In the SnCl3− compounds, the Mössbauer parameters indicate that the solvent molecules are not bonded to the Sn atom. In compounds containing Sn—Ni bonds, the center shifts and quadropole splittings show that Ni(PPh3)Cp is the best donor of the first row transition metal moieties, and that the Sn—Ni bond has the highest Sn s character. Ni(CO)Cp is a slightly poorer donor than Ni(PPh3)Cp, and the Sn—Ni bond has a smaller s character.

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.

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