4f–4f Spectral Analysis and Solvent Effect for the Interaction of Pr(III) with l-Tryptophan Using Different Aquated Solvents in the Presence and Absence of Zn(II)

Abstract

In this study, the absorption spectra due to the interaction between Pr(III) and l-tryptophan system exhibiting 4f–4f transitions in presence and absence of Zn(II) using different aquated organic solvents such as methanol, dioxane, acetonitrile and N,N-dimethylformamide (DMF) were investigated and the same were also analyzed for the equimolar mixtures (1:1) of two different solvents. The energy parameters such as Slater–Condon (FK) factor, Lande spin–orbit coupling constant ($$\xi_{4f}$$), Nephelauxetic ratio ($$\beta )$$, bonding parameter (b1/2) and percent covalency ($$\delta )$$, are also calculated and the observed variation in these parameters with the change of solvents indicates the nature of bond formed between Pr(III) and l-tryptophan. The oscillator strength (P) and Judd–Ofelt parameters Tλ (λ = 2, 4, 6) have also been determined for the four transitions namely 3H4 to 3P2, 3P1, 3P0 and 1D2.The solvent DMF has the most effective for the promotion of 4f–4f electric dipole intensity. Comparative absorption spectra of Pr(III):l-Tryptophan in different solvents.