Absorption spectral studies of 4f–4f transitions for the complexation of Pr(III) and Nd(III) with glutathione reduced (GSH) in presence of Zn(II) in different aquated organic solvents and kinetics for the complexation of Pr(III):GSH with Zn(II)

Comparative absorption and spectral analysis of 4f–4f transitions of the heterobimetallic complexation of glutathione reduced (GSH) with Pr(III) and Nd(III) in presence of Zn(II) has been explored in different aquated organic solvents like methanol (CH3OH), acetonitrile (CH3CN), dioxane, DMF and their equimolar mixtures. The variation in the energy parameters like Slater Condon (FK), Racah (EK) and Lande (ξ4f), Nephelauxetic parameter (β) bonding parameter (b1/2) and percent covalency parameter (δ) are computed to explain the nature of complexation. The values of experimentally calculated oscillator strengths (P) and computed values of Judd–Ofelt electric dipole intensity parameters, Tλ (λ = 2, 4, 6) are studied for different 4f–4f transitions in different experimental conditions. The changes in the values of oscillator strengths (P) and Tλ parameters also suggest the specific correlation between relative intensities, ligand structures and nature of interaction of Pr(III) and Nd(III) with GSH in presence of Zn(II). Kinetics for the formation of the complex, Pr(III):GSH:Zn(II) have also been studied at different temperatures in DMF medium and activation energy (Ea) of the complexation is calculated.