Intrinsically incompatible crystal (ligand) field parameter sets for transition ions at orthorhombic and lower symmetry sites in crystals and their implications

2010 ◽  
Vol 405 (1) ◽  
pp. 113-132 ◽  
Author(s):  
C. Rudowicz ◽  
P. Gnutek
1966 ◽  
Vol 19 (2) ◽  
pp. 207 ◽  
Author(s):  
RW Adams ◽  
E Bishop ◽  
RL Martin ◽  
G Winter

The magnetic moments and electronic spectra are reported for the following divalent transition metal methoxides: Cr(OCH3)2, Mn(OCH3)2, Fe(OCH3)2, Co(OCH3)2, Ni(OCH3)2, and Cu(OCH3)2. These measurements when coupled with the involatility and insolubility of the compounds favour structures based on infinite lattices composed either of regular (Mn, Fe, Co, and Ni) or distorted (Cr and Cu) MO6 octahedra. The spectral data place the ligand field parameter, Δ, for the methoxide group very close to that of water.


1956 ◽  
Vol 10 ◽  
pp. 1501-1503 ◽  
Author(s):  
Ole Bostrup ◽  
Chr. Klixbüll Jørgensen ◽  
R. A. Cox ◽  
A. R. Peacocke

1975 ◽  
Vol 30 (11-12) ◽  
pp. 970-972 ◽  
Author(s):  
Claus Friebel

From EPR and ligand field parameter some significant structural details of Cu(II)-compounds can be determined to a notable accuracy: a) the symmetry (tetragonal or orhombic) of Jahn-Teller distorted octahedral Cu(II)-sites, and b) the ordering of Jahn-Teller coupled Cu(II)-polyhedra with respect to each other as well as to the crystallographic axes of the Cu(II)-compound under investigation.


1977 ◽  
Vol 55 (13) ◽  
pp. 2473-2477 ◽  
Author(s):  
K. C. Lee ◽  
F. Aubke

The syntheses of Pd(SO3F)2 and Pd(SO3F)3 by the reactions of palladium with BrOSO2F and S2O6F2 are described. Structural information on both compounds is based on infrared, Raman, diffuse reflectance, and electronic mull spectra as well as magnetic measurements from ∼300 to ∼100 K. Palladium bisfluorosulfate is found to have a polymeric structure with the fluorosulfate group acting as a tridentate ligand. As a consequence, an octahedral environment is found for Pd2+ with a 3A2g ground state, a µeff298 value of 3.39 BM and the ligand field parameter Dq = 1177 cm−1 and B = 633 cm−1. Pd(SO3F)3 is best regarded as PdII[PdIV(SO3F)6].


1998 ◽  
Vol 51 (3) ◽  
pp. 229 ◽  
Author(s):  
Philip A. Reynolds ◽  
Brian N. Figgis ◽  
Boujemaa Moubaraki ◽  
Keith S. Murray

The magnetic susceptibilities of tris(acetylacetonato)ruthenium(III) have been measured between 2·5 and 300 K along the a, b, c, and a* axis directions, together with the magnetizations along the same directions up to a magnetic field of 5 T. There is a small amount of magnetic exchange interaction apparent below 10 K, with Weiss constants up to –0·35 K and the magnetization is fitted with exchange integrals up to –0·38 K in magnitude. A pathway for magnetic exchange in terms of a pair of symmetry-related Ru(acac) rings lying parallel and close is obvious from the structure. The susceptibility results above 10 K have been interpreted in terms of a four-parameter ligand field model (CF1) operating on the ground 2T2g term of the d5 configuration. The t2g orbitals are found to be split by 475 cm-1 by a dominant trigonal symmetry component and then by –50 cm-1 by a subsidiary rhombic component. The single-electron spin-orbit coupling constant is 875 cm-1 and the orbital angular momentum reduction parameter is 0·7. The g-values deduced for the ground Kramers doublet are not in good agreement with those from e.s.r. experiments, but rather better agreement is found for closely allied ligand field parameter sets (CF2) which can fit the susceptibilities at particular temperatures but do not reproduce their temperature dependence well. Consideration of the variation of structural details with temperature indicate that, in fact, the CF2 sets may be more realistic.


1971 ◽  
Vol 74 (1_2) ◽  
pp. 11-16 ◽  
Author(s):  
I. Gănescu ◽  
Margareta Teodorescu ◽  
C. I. Lepădatu
Keyword(s):  

1988 ◽  
Vol 53 (1) ◽  
pp. 56-60
Author(s):  
Anna Mašlejová ◽  
Reinhard Kirmse

ESR spectra of thianatocopper(II) complexes with imidazole derivatives were studied in ethanolic solutions at 295 and 123 K. Axialsymmetric spectra, attributed to the monomeric complex units, were obtained for the frozen solutions. The bonding parameters were interpreted by using calculated g, Cu-hyperfine, and 14N-ligand hyperfine splitting values. The Cu-N bond parameters indicate a considerable delocalization of the unpaired electron. The values of the isotropic Cu-hyperfine splitting suggest that the deviations from the planar symmetry of the CuN4 units are due to tetrahedral perturbation of the ligand field.


1998 ◽  
Vol 63 (5) ◽  
pp. 628-635 ◽  
Author(s):  
Jana Holubová ◽  
Zdeněk Černošek ◽  
Ivan Pavlík

The effect of the halide ligand on the bonding of niobium in niobocene dichloride and niobocene diiodide was investigated. The electronic absorption spectra of the two compounds in the range of d-d transitions were resolved into four bands corresponding to transitions of the d1 electron between five frontier orbitals in a molecule of symmetry point group C2v. The energies of the frontier molecular orbitals were determined relatively to the energy of the orbitals in the spherically symmetric ligand field formed by the appropriate halide ligands. The effect of the halide ligands on the spin-orbital interaction of the HOMO orbital is discussed qualitatively on the basis the ESR spectra.


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