Figure 8.
Studies on protonation of the metal ion complex by acid titration of the 15-Zn2+ complex (ccomplex = 10 μM, λexcitation= 249 nm, filter = 350 nm cut-off, slit width = 3 nm) with nitric acid in acetonitrile as an example (A) Series of fluorescence emission spectra for acid titration of the 15-Zn2+ complex, (B) Globally fitted nonlinear regression curve for determination of pKa.