Figure 1.

Absorption spectra of Fe^III–HTRAP⁵⁻-Bha⁻ equilibrium systems. Open symbols and solid lines represent experimental and calculated absorbance values, respectively. ([Fe(TRAP)(OH)_x^(−3−x)] = 0.2 mM, [HBha] = 0.0 mM (black). $0.25$ mM (blue), $0.5$ mM (purple), $0.75$ mM (green), $1.0$ mM (brown), and $1.5$ mM (red), x = 0 and 1, pH = 10.0, 0.15 M NaNO₃, 25°C).