Variable temperature EPR study for confirming dynamic Jahn–Teller distortion in Cu(II) doped zinc ammonium phosphate hexahydrate

An electron magnetic resonance and optical study of Cu2+-doped zinc ammonium phosphate hexahydrate single crystals

“…So, in the present study, we report an EPR and optical absorption study of Cu 2+ -doped ZAPH to obtain site symmetry, associated distortion in the lattice and energy level structure, as well as to discuss the nature of the bonding of the metal ion with different ligands. Poonguzhali et al [9,10] have carried out an EPR and optical study of Cu 2+ -doped ZAPH, but they observed a single site in EPR and four bands in optical absorption due to an inappropriate concentration of dopant in the host lattice [8], which, as a result, yielded different EPR and optical absorption spectra compared to the present study. In our study of Cu 2+ -doped ZAPH, two magnetically inequivalent substitutional sites with spin Hamiltonian parameters slightly different from those reported earlier in EPR and five bands instead of four [9,10] in optical absorption are obtained.…”

Catecholase Activities of Copper(II) Complexes With N4 Ligands

“…g (par) regions are further split by the copper ( I = 3/2) nuclear hyperfine couplings of 160 G for 1 and 163 G for 2 . Since the g (par) > g (per) > g e (=2.0023), the unpaired electron resides on d ( x 2 ‐y 2 ) orbital at the ground state as expected for the complexes in a square pyramidal geometry with a Jahn–Teller effect or a slight equatorial distortion 61–66 …”

“…Since the g (par) > g (per) > g e (=2.0023), the unpaired electron resides on d(x 2 -y 2 ) orbital at the ground state as expected for the complexes in a square pyramidal geometry with a Jahn-Teller effect or a slight equatorial distortion. [61][62][63][64][65][66] The electrochemical properties of the complexes were investigated. Figure 3 displays the cyclic voltamograms of compounds 1 and 2, respectively, measured at a platinum electrode in an acetonitrile solution containing 0.1 M tris(pbromophenyl)amine electrolyte with AgCl/Ag reference electrode.…”

On the dielectric spectroscopy of copper doped layered Na1.6K0.4Ti3O7 ceramics

“…The observation that g II > g ⊥ > 2 indicates that the ground state of the Cu 2+ ion in the distorted octahedral (tetragonal) complex is d x 2 −y 2 [28]. The observed distorted octahedral symmetry of copper complexes suggests that copper occupies Ti 4+ site with divalent oxidation state (Cu 2+ ) giving rise to oxygen vacancy in the lattice required for charge neutrality of the lattice, thereby generating electric dipoles [29][30][31][32]. For the samples having higher concentration of dopants, it can be seen that the peaks get broadened due to dipolar broadening and the exchange interaction of neighboring copper atoms.…”