Emission-titration studies of the formation of adducts of tris(6,6,7,7,-8,8,8- heptafluoro-2,2-dimethyloctane-3,5-dionato)europium(III) with substrates in solution

Abstract

Emission-titration spectroscopy has been used to study the formation of adducts of the title complex. [Eu(fmod)_a]. with substrates in CCl₄ solution. The emission intensity of the ⁵D₀→⁷F₂, Eu³⁺ transition in [Eu(fmod)₃] is very sensitive to interactions between the complex and substrate molecules containing a nucleophilic functional group. Adduct formation between the complex system and a substrate molecule is generally accompanied by a sharp increase in complex emission intensity. Stepwise addition (titration) of substrate to a [Eu(fmod)₃]-CCl₄ solution leads to an emission-titration curve (complex emission intensity plotted as a function of the amount of substrate added) whose shape and limiting values are diagnostic of adduct structure and adduct-formation mechanisms.