In the present investigation, studies on difference in energy interaction parameters and comparative absorption spectrophotometry involving 4ƒ-4ƒ transitions of Pr(III) with dibenzoyl methane [Pr(dbm)3(H2O)2] and their adducts with dinitrogen donor ligands like ophenanthroline (phen) and bipyridyl (bipy) complexes in different solvents like CH3OH, CH3CN and DMF have been carried out. Variation in the spectral energy interaction parameters like Salter Condon (FK,EK), Lande spin orbit coupling (ξ4f), nephelauxetic ratio (β), bonding parameter (b1/2), percent covalency (δ) were calculated and intensity parameters have been computed on computer using partial multiple regression analysis. The difference in the energy parameters with respect to nitrogen donor atoms and with various solvents reveals that the chemical environment around the Pr(III) ion has great impact on 4ƒ-4ƒ transition. Any change in the environment results in modification of the absorption spectra.
