Complexation of Pr3+ with L-methionine in the presence/absence of Mg2+ : Their reaction dynamics and thermodynamic properties

Abstract

The 4f-4f transition spectra for the bimetallic complexation of the 2-amino-4-(methylthio) butanoic acid with Pr(III) and Mg(II) has been explored in aquated organic solvents (50% v/v) of CH3CN, DMF, CH3OH, and C4H8O2. In DMF medium our study is extended for different pH (2, 4, 6). The variations in the theoretically computed values of the absorption spectral parameters: bonding parameter (b1/2), nephelauxetic ratio (β), Slater-Condon (Fk), Spin-orbit interaction (ξ4f), Racah energy (Ek), and percentage covalency (δ) could provide the detailed information about the nature of complexation theoretically. The values of evaluated oscillator strengths (P) and Judd-Ofelt electric dipole intensity parameters(Tλ,λ=2,4,6) were analyzed to see the possibility of inner and outer sphere coordination of Pr(III) with methionine in presence and absence of Mg(II). Further, the mode of complexation was studied through kinetic and thermodynamic studies.

Keywords

• Lanthanide
• Methionine
• Nephelauxetic-ratio
• Judd-Ofelt
• Pseudohypersensitive