Evaluation of intensity and energy interaction parameters for the complexation of Pr(III) with selected nucleoside and nucleotide through absorption spectral studies

Abstract

The interactions of Pr(III) with nucleosides and nucleotides have been studied in different organic solvents employing absorption difference and comparative absorption spectrophotometry. The magnitudes of the variations in both energy and intensity interaction parameters were used to explore the degree of outer and inner sphere co-ordination, incidence of covalency and the extent of metal 4f-orbital involvement in chemical bonding. Various electronic spectral parameters like Slater–Condon (Fk), Racah (Ek), Lande parameter (ξ4f), Nephelauxatic ratio (β), bonding (b1/2), percentage covalency (δ) and intensity parameters like oscillator strength (P) and Judd Ofelt electronic dipole intensity parameter (Tλ, λ=2,4,6) have been evaluated. The variation of these evaluated parameters were employed to interpret the nature of binding of Pr(III) with different ligands i.e. Adenosine/ATP in presence and absence of Ca2+.