Investigation of the EPR parameters and local structures for Cu2+ in Bis(l-asparaginato) M(II) catalysts (M=Zn, Cd, Mg)

Theoretical studies of the local structures and EPR parameters for Cu^{2+} center in Cd_{2}(NH_{4})_{2}(SO_{4})_{3} single crystal

“…A 2 (R 0 ), and A 4 (R 0 ) are intrinsic parameters with the reference distance R 0 [taken as R 0 = R = (R x + R y + R z )/3]. The ratio A 2 (R 0 )/A 4 (R 0 ) was found to be in the range 9 − 12 as per several studies of optical and EPR spectra using superposition model for 3d n ions in crystals [12,[19][20][21][22]. Here, we take A 2 (R 0 )/A 4 (R 0 ) = 12.…”

“…When Cu 2+ is doped in CAS crystal, it enters the lattice at Cd 2+ site. For a 3d 9 (Cu 2+ ) ion in an octahedral complex with a rhombic elongation it would give g z > g x , g y > 2 [12,14,15].…”

“…Here, t 2 ≈ 3 and t 4 ≈ 5 are the power-law exponents due to the dominant ionic nature of the bonds [9,12,[18][19][20]. A 2 (R 0 ), and A 4 (R 0 ) are intrinsic parameters with the reference distance R 0 [taken as R 0 = R = (R x + R y + R z )/3].…”

“…Among these transition metal ions, Cu 2+ ions with 3d 9 configuration are widely used as paramagnetic probes as they represent a relatively simple one-hole magnetic system which can be used to obtain information regarding the electron wave function when there is a ligand field of low symmetry. Thus, EPR spectra of Cu 2+ ion in different diamagnetic host lattices have been studied by many workers to get some data on the structure, dynamics and environment of host lattices [8][9][10][11][12]. For example, the EPR experiments were carried out for Cu 2+ doped in CAS single crystal, and the EPR parameters (anisotropic g factors g i and the hyperfine structure constants A i , i = x, y, z) were also measured for rhombic Cu 2+ center [13].…”