Figure 2. Effect of the addition of CaDPA on an aqueous solution of [Eu(Bn)]⁺.

(A) Absorption profile for the formation of Bn by the addition of CaDPA to a solution of [Eu(Bn)]⁺; The numbers in the curves indicate the concentration of CaDPA in equivalents of Bn. (B) Picture of a microplate containing Bn and increasing amounts of EuCl₃ and CaDPA, the background was removed for clarity. [Bn] = 5.8 µmol L^–1, [EuCl₃] = 34.8 µmol L^–1 (6 equiv) in MOPS buffer pH = 7.5.