The interaction of Pr (III) with thenoyltrifluoroacetone [C8H5F3O2S] has been explored in presence of ophenanthroline [C12H8N2] and bipyridyl [C10H8N2]. Using comparative absorption spectroscopy involving 4ƒ-4ƒ transition in various solvents like methanol (CH3OH), acetonitrile (CH3CN) and dimethylformamide [(CH3)2NCOH]. The change in coordination sphere in various solvent medium is observed. The 4ƒ-4ƒ transition spectra yield sharp bands which were analyzed individually by Gaussian curve analysis, the energy interaction parameters (FK,EK), Lande spin orbit coupling (ξ4f), nephelauxetic ratio (β), bonding parameter (b1/2), percent covalency (δ), oscillator strength were calculated and intensity parameters have been computed on computer using partial multiple regression analysis.
