Computation of energy interaction parameters as well as electric dipole intensity parameters for the absorption spectral study of the interaction of Pr(III) with l-phenylalanine, l-glycine, l-alanine and l-aspartic acid in the presence and absence of Ca2+ in organic solvents.

Studying the absorption difference and comparative absorption spectra of the interaction of Pr(III) and Nd(III) with l-phenylalanine, l-glycine, l-alanine and l-aspartic acid in the presence and absence of Ca(2+) in organic solvents, various energy interaction parameters like Slater-Condon (F(K)), Racah (E(k)), Lande factor (xi(4f)), nephelauxetic ratio (beta), bonding (b(1/2)), percentage-covalency (delta) have been evaluated applying partial and multiple regression analysis. The values of oscillator strength (P) and Judd-Ofelt electric dipole intensity parameter T(lambda) (lambda = 2, 4, 6) for different 4f-4f transitions have been computed. On analysis of the variation of the various energy interaction parameters as well as the changes in the oscillator strength (P) and T(lambda) values reveal the mode of binding with different ligands.