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 (F K ) factor, Lande spin-orbit coupling constant ( 4f ), Nephelauxetic ratio ( ) , bonding parameter (b 1/2 ) and percent covalency ( ) , 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 T λ (λ = 2, 4, 6) have also been determined for the four transitions namely 3 H 4 to 3 P 2 , 3 P 1 , 3 P 0 and 1 D 2 .The solvent DMF has the most effective for the promotion of 4f-4f electric dipole intensity. Graphic abstractComparative absorption spectra of Pr(III):l-Tryptophan in different solvents.