Parameters, crystal field

West and colleagues206 have reported the initial examples involving a N -> O/S -> O mixed donor ligand such as 2-(ethylsulphinyl)pyridine A-oxide for transition metal ion and lanthanide metal ion as shown in Scheme 22. Crystal field parameters based on... 

The electrostatic and spin-orbit parameters for Pu + which we have deduced are similar to those proposed by Conway some years ago (32). However, inclusion of the crystal-field interaction in the computation of the energy level structure, which was not done earlier, significantly modifies previous predictions. As an approximation, we have chosen to use the crystal-field parameters derived for CS2UCI6 (33), Table VII, which together with the free-ion parameters lead to the prediction of a distinct group of levels near 1100 cm-. Of course a weaker field would lead to crystal-field levels intermediate between 0 and 1000 cm-1. Similar model calculations have been indicated in Fig. 8 for Nplt+, Pu1 "1 and Amlt+ compared to the solution spectra of the ions. For Am t+ the reference is Am4" in 15 M NHhF solution (34). 

Table VII. Crystal-Field Parameters for Hexahalide 5f -Actinide Ions.

S is the ionic spin and D, ID, and a are crystal field parameters describing the strength of the axial, the rhombohedral, and the cubic crystal field terms, respectively. The coordinate system of the cubic crystal field (ij, rj, g) may differ from that used to describe the axial and the rhombohedral crystal field interactions (x,y,z). 

The Wyboume crystal field parameters B (f, f), B (d, d), and Bjj(f, d), which describe the interaction due to the presence of the ligands onto the electrons of the lanthanide center. They are deduced from the ligand field energies and wave functions obtained from Kohn—Sham orbitals of restricted DFT calculations within the average of configuration (AOC) reference by placing evenly n — 1 electrons in the 4f orbitals and one electron in the 5d.33... 

Wenger OS, Giidel HU (2003) Influence of Crystal Field Parameters on Near-Infrared to Visible Photon Upconversion in Ti2+ andNi2+ Doped Halide Lattices 106 59-70 Wheatley AEH, see Linton DJ (2003) 105 67-139 Wilhelm M, see Haubner R (2002) 102 1-46... 

Table 2.1 Non-forbidden crystal field parameters that a group of point charges may contribute collectively, as a function of their point-group symmetry.

How to Determine the Crystal-Field Parameters 1. The Ishikawa Approach... 

Edvarsson, S. and Klintenberg, M. (1998) Role of the electrostatic model in calculating rare-earth crystal-field parameter. 

E., Gaita-Arino, A. Palii, A. (2014) An Updated Version of the Computational Package SIMPRE that Uses the Standard Conventions for Stevens Crystal Field Parameters. /. Comput. Chem., 35, 1930-1934. 

Table 6.5 Crystal-field parameters for Ishikawa s [Tb(Pc)2] complex obtained ab initio for the experimental geometry [80], for the symmetrized geometry [80] and those obtained from the fitting of the experimental data [1, 78].

These paramagnetic, air-stable complexes could equally well be formulated as Os " arylnitrenes. Both crystal-field and charge-transfer bands have been observed in the diffuse reflectance spectrum of [OSF5] . Calculation of the spin-orbit coupling constant and crystal-field parameters indicated that the degree of covalency is high for a fluorocomplex, and comparable with that found for quadrivalent [MFg] species of the first transition series. ... 

The EPR powder spectra of the low-spin complexes [0s(NH3)5L][CF3S03]3 (L = H20 or (5)) have been analyzed the negative sign obtained for the axial splitting when L = (5) has been rationalized in terms of Os L backbonding. Crystal field parameters have also been derived. The spectral and electrochemical properties of [Ru(NH3)5L]" (Ru or Ru L =RC02 R = 4-py-A-Me+ or L = RCONH R = Ph, 4-py-A-Me", 4-py-A-H+) have been studied in detail as a function of pH the carboxamido Ru complexes are weak bases and are deprotonated only in strongly acidic solution. ... 

Crystal field theory enables us to define certain parameters in order to characterize and distinguish the different europium site configurations. Crystal field parameter calculation involves several steps ... 

Calculation of the B20 and B22 crystal field parameters using the three following equations ... 

The effective and ordered moments in a cubic crystal field were also calculated using the obtained gj values and the wave functions given by Lea, Leask and WolP In the case of the Tg quadruplet the magnetic moment is anisotropic and depends upon the crystal field parameter x. The effective moment is space averaged and given as a function x ° The value of the ordered moment along (001) is given as a function of x also. 

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