Complex formation of 4‐[3,5‐bis(2‐hydroxyphenyl)‐1,2,4‐triazol‐1‐yl]benzoic acid (ICL670, H3Lx), 4‐[3,5‐bis(2‐hydroxyphenyl)‐1,2,4‐triazol‐1‐yl]benzosulfonic acid (H3Ly), and 3,5‐bis(2‐hydroxyphenyl)‐1‐phenyl‐1,2,4‐triazole (H2Lz) with Fe3+ and Fe2+ was investigated in H2O and in H2O/DMSO mixtures by potentiometry, spectrophotometry and cyclic voltammetry. ICL670 has previously been considered as a promising drug for an oral treatment of iron overload. In this paper, the stability and redox properties of the various FeII and FeIII complexes were elucidated with a particular focus on their potential involvement in the generation of oxidative stress. The overall stability constants of [FeIII(Lx)] and [FeIII(Lx)2]3− (25 °C, 0.1 M KCl in H2O) are log β1 = 22.0 and log β2 = 36.9, respectively. The affinity of these ligands for Fe2+ is remarkably poor. In particular, the 1:2 complexes [FeII(Lx)2]4− and [FeII(Ly)2]4− were found to be less stable. As a consequence, the redox chemistry of the [FeIII(Lx)]/[FeII(Lx)]− and the [FeIII(Lx)2]3−/[FeII(Lx)2]4− couples differs significantly. [FeIII(Lx)2]3− is a very weak oxidizing agent (E1/2 is approximately −0.6 V versus NHE) and reduction of [FeIII(Lx)2]3− is not anticipated under physiological conditions. The reduction potential of the [FeIII(Lx)]/[FeII(Lx)]− couple is considerably less negative and was estimated to be +0.1 V (versus NHE). The possible roles of the various Fe complexes as catalysts for the Fenton reaction in biological media are discussed. The crystal structures of H3Lx, Na[Fe(Lz)2]·4EtOH, Na[Al(Lz)2]· 4EtOH, and [Cu(Lz)(pyridine)]2 were investigated by single‐crystal X‐ray diffraction, and the possible influence of the particular steric requirements of these ligands on the stability of the metal complexes has been analyzed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

The pFe values of the two ligands H3Lx and H3Ly in section 2.3 on page 4183 of the original article[1] are incorrect; the corresponding sentence with the correct values should read as follows: In general, the iron binding properties of H3Lx and H3Ly are indeed closely related: the pFe values[30] for H3Lx and H3Ly (total [L] = 10 μM, total [Fe] = 1 μM, pH = 7.4, H2O, I = 0.1 M) are 23.5 and 22.6, respectively.

The new, tridentate, facially coordinating ligand 1,4-diazepan-6-amine (daza) has been prepared from ethane-1,2-diamine and 2,3-dibromo-1-propanol in a seven-step procedure with an overall yield of 22 %. The conformation of the free ligand has been elucidated by pH-and temperaturedependent 1 H NMR spectroscopy and by a single-crystal Xray structure analysis of H 3 dazaCl 3 ·H 2 O. A twisted chair with a predominantly equatorial orientation of the primary amino group has been established for daza and its protonation products

The complex formation of vanadium(IV) with 1,3,5-triamino-1,3,5-trideoxy-cis-inositol (taci) and 1,3,5-trideoxy-1,3,5-tris(dimethylamino)-cis-inositol (tdci) was studied in aqueous solution and in the solid state. The formation constants of [V(IV)O(taci)](2+), [V(IV)O(tdci)](2+), and [V(IV)(tdci)(2)](4+) and of the deprotonation product [V(IV)(tdci)(2)H(-)(1)](3+) were determined (25 degrees C, 0.1 M KNO(3)). Cyclic voltammetry measurements established a reversible one-electron transfer for the [V(IV)(tdci)(2)H(-)(m)]((4)(-)(m))/[V(III)(tdci)(2)H(-)(n)]((3)(-)(n)) couple (0

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