Complexes of 2-Mercaptopyrimidin-4-ol(2-thiouracil) with RhIII, PdII, PdIV, PtII and PtIV

1975 ◽  
Vol 28 (7) ◽  
pp. 1529 ◽  
Author(s):  
IP Khullar ◽  
U Agarwala
Keyword(s):  
Metal Ions ◽  
Crystal Field ◽  
Electronic Spectra ◽  
Analytical Data ◽  
Bridging Ligand ◽  
Crystal Field Parameters

Complexes of 2-mercaptopyrimidin-4-ol with RhIII, PdII, PdIV, PtII and PtIV have been prepared. Their tentative structures have been assigned on the basis of infrared and electronic spectra and magnetic and analytical data. The ligand behaves as a bidentate bridging ligand towards metal ions except for PtII. Crystal field parameters have also been calculated.

1,3,4-Thiadiazole-2,5-dithiol as a complexing agent. Complexes of RuIII, RuII, RhIII, PdIV IrIII and PtIV

1975 ◽  
Vol 28 (4) ◽  
pp. 763 ◽  
Author(s):  
MR Gajendragad ◽  
U Agarwala
Keyword(s):  
Magnetic Susceptibility ◽  
Metal Ions ◽  
Spectral Data ◽  
Crystal Field ◽  
Complexing Agent ◽  
Chemical Analyses ◽  
Infrared Spectral ◽  
Crystal Field Parameters

Complexes of RuIII, RuII, RhIII, PdIV, IrIII and PtIV with 1,3,4-thiadiazole- 2,5-dithiol have been prepared. Probable structures for the complexes have been proposed on the basis of chemical analyses, magnetic susceptibility and electronic and infrared spectral data. Crystal field parameters have been calculated which are in accordance with the structures proposed. In every complex the ligand behaves as a unidentate towards two metal ions.

An Intuitive Method for the Determination of Crystal-Field Parameters in Laser Crystals

1993 ◽  
Vol 329 ◽  
Author(s):  
Frederick G. Anderson ◽  
H. Weidner ◽  
P. L. Summers ◽  
R. E. Peale ◽  
B. H. T. Chai
Keyword(s):  
Crystal Field ◽  
Irreducible Representations ◽  
Laser Crystals ◽  
Intuitive Method ◽  
Crystal Field Parameters ◽  
Intuitive Interpretation

AbstractExpanding the crystal field in terms of operators that transform as the irreducible representations of the Td group leads to an intuitive interpretation of the crystal-field parameters. We apply this method to the crystal field experienced by Nd3+ dopants in the laser crystals YLiF4, YVO4, and KLiYF5.

Ground configuration splitting in UCl5

1977 ◽  
Vol 55 (10) ◽  
pp. 937-942 ◽  
Author(s):  
A. F. Leung ◽  
Ying-Ming Poon
Keyword(s):  
Crystal Field ◽  
Energy Levels ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupling Constant ◽  
Point Charge Model ◽  
X Ray Crystallography ◽  
Charge Model ◽  
Crystal Field Parameters

The absorption spectra of UCl5 single crystal were observed in the region between 0.6 and 2.4 μm at room, 77, and 4.2 K temperatures. Five pure electronic transitions were assigned at 11 665, 9772, 8950, 6643, and 4300 cm−1. The energy levels associated with these transitions were identified as the splittings of the 5f1 ground configuration under the influence of the spin–orbit coupling and a crystal field of C2v symmetry. The number of crystal field parameters was reduced by assuming the point-charge model where the positions of the ions were determined by X-ray crystallography. Then, the crystal field parameters and the spin–orbit coupling constant were calculated to be [Formula: see text],[Formula: see text], [Formula: see text], and ξ = 1760 cm−1. The vibronic analysis showed that the 90, 200, and 320 cm−1 modes were similar to the T2u(v6), T1u(v4), and T1u(v3) of an UCl6− octahedron, respectively.

Studies of local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) crystals

2021 ◽  
Vol 76 (4) ◽  
pp. 299-304
Author(s):  
Fu Chen ◽  
Jian-Rong Yang ◽  
Zi-Fa Zhou
Keyword(s):  
Crystal Field ◽  
Elongation Ratio ◽  
Paramagnetic Resonance ◽  
Local Structures ◽  
Epr Parameters ◽  
Structure Constants ◽  
Crystal Field Parameters ◽  
Electron Paramagnetic ◽  
Theoretical Results ◽  
Good Agreement

Abstract The electron paramagnetic resonance (EPR) parameters (g factor g i , and hyperfine structure constants A i , with i = x, y, z) and local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) are theoretically investigated using the high order perturbation formulas of these EPR parameters for a 3d 9 ion under orthorhombically elongated octahedra. In the calculations, contribution to these EPR parameters due to the admixture of d-orbitals in the ground state wave function of the Cu2+ ion are taken into account based on the cluster approach, and the required crystal-field parameters are estimated from the superposition model which enables correlation of the crystal-field parameters and hence the studied EPR parameters with the local structures of the Cu2+ centers. Based on the calculations, the Cu–H2O bonds are found to suffer the axial elongation ratio δ of about 3 and 2.9% along the z-axis, meanwhile, the planar bond lengths may experience variation ratio τ (≈3.8 and 1%) along x- and y-axis for Cu2+ center in (NH4)2Zn(SO4)2·6H2O and Rb2Zn(SO4)2·6H2O, respectively. The theoretical results show good agreement with the observed values.

Pseudocontact shifts in lanthanide complexes with variable crystal field parameters

2011 ◽  
Vol 255 (23-24) ◽  
pp. 2810-2820 ◽  
Author(s):  
Sebastiano Di Pietro ◽  
Samuele Lo Piano ◽  
Lorenzo Di Bari
Keyword(s):  
Crystal Field ◽  
Lanthanide Complexes ◽  
Pseudocontact Shifts ◽  
Crystal Field Parameters

Electronic transitions and genuine crystal-field parameters in copper metaborate CuB2O4

2011 ◽  
Vol 84 (7) ◽  
Author(s):  
R. V. Pisarev ◽  
A. M. Kalashnikova ◽  
O. Schöps ◽  
L. N. Bezmaternykh
Keyword(s):  
Crystal Field ◽  
Electronic Transitions ◽  
Crystal Field Parameters

Role of the electrostatic model in calculating rare-earth crystal-field parameters

1998 ◽  
Vol 275-277 ◽  
pp. 230-233 ◽  
Author(s):  
Sverker Edvardsson ◽  
Mattias Klintenberg
Keyword(s):  
Rare Earth ◽  
Crystal Field ◽  
Electrostatic Model ◽  
Crystal Field Parameters

Studies of Distorted Octahedral Complexes of Cobalt, Nickel and Copper and Their Antibacterial Properties

2018 ◽  
Vol 34 (4) ◽  
pp. 1937-1944 ◽  
Author(s):  
Vijay Kumar ◽  
Rajiv Kumar Singh ◽  
Veena Kumari ◽  
Birendra Kumar ◽  
Shivadhar Sharma
Keyword(s):  
Magnetic Moment ◽  
Electronic Spectra ◽  
Antibacterial Properties ◽  
Octahedral Geometry ◽  
Azomethine Nitrogen ◽  
Distorted Octahedral Geometry ◽  
Octahedral Symmetry ◽  
Orbital Contribution ◽  
Distorted Octahedral ◽  
Crystal Field Parameters

The ligand, 3-hydroxy-4-methoxybenzaldehydethiosemicarbazone has been prepared by the condensation of 3-hydroxy-4-methoxybenzaldehyde and thiosemicarbazide. With the help of this ligand the complexes of Co(II), Ni(II) and Cu(II) have been prepared with general formula [ML2X2] where X is secondary ligand, Cl–, NO3– and CH3COO–. The composition of complexes has been established by their microanalysis, while the metal contents have been determined gravimetrically and volumetrically. On the basis of IR spectra, the coordinating mode of ligand has been determined and has been found to have coordinated through azomethine nitrogen and thione sulphur. The magnetic moment of Co(II) complexes has been found between 4.96-4.72 B. M. The value is slightly higher than the μs value corresponding to three unpaired electrons (3.872 B.M). The increase in value may be attributed to orbital contribution from 4T1g ground state cubic term. The appearance of four bands in their electronic spectra is indicative of tetragonally distorted octahedral geometry of Co(II) complexes. The magnetic moment (3.20-3.30 B. M.) and appearance of 4 bands in the electronic spectra of Ni(II) complexes confirms the distorted octahedral geometry of the complexes. The magnetic moment of Cu(II) complexes has been determined to be (1.95-2.20 B. M.) which shows that Cu(II) complexes are magnetically dilute complexes. The appearance of three bands in their electronic spectra confirms John - Tellor distortion in octahedral symmetry of Cu(II) complexes. The various crystal field parameters exhibiting tetragonal distortion in the octahedral symmetry have also been derived. The positive value of Dt predicts tetragonal elongation in Oh symmetry.

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