The electrochemical reduction of phenylazide or phenylacetylene diazonium salts leads to the grafting of azido or ethynyl groups onto the surface of carbon electrodes. In the presence of copper(I) catalyst, these azide- or alkyne-modified surfaces react efficiently and rapidly with compounds bearing an acetylene or azide function, thus forming a covalent 1,2,3-triazole linkage by means of click chemistry. This was illustrated with the surface coupling of ferrocenes functionalized with an ethynyl or azido group and the biomolecule biotin terminated by an acetylene group.

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Two crystal structures are described in this article: (a) the structure of a monomeric MnII complex with the tridentate N‐centered N3 ligand tris[(1‐methyl‐2‐imidazolyl)methyl]amine (TMIMA) ([MnII(TMIMA)2]2+); and (b) the structure of a monomeric MnIII complex with the tridentate N‐centered N2O ligand 2‐{[(1‐methyl‐2‐imidazolyl)methyl]amino}phenolate (PI–)2 ([MnIII(PI)2]+) (5). The latter was isolated both in the MnII and in the MnIII state, although only MnIII crystals were successfully grown. They are part of a series of Mn complexes prepared as SOD mimics, namely [Mn(BMPG)(H2O)]+ (2) {BMPG = N,N‐bis[(6‐methyl‐2‐pyridyl)methyl]glycinate}, [Mn(IPG)(MeOH)]+ (3) {IPG = N‐[(1‐methyl‐2‐imidazolyl)methyl]‐N‐(2‐pyridylmethyl)glycinate}, [Mn(BIG)(H2O)2]+ (4) {BIG = N,N‐bis[(1‐methyl‐2‐imidazolyl)methyl]glycinate}. The reactivity of MnII complexes 1 and 2 in an anhydrous medium is described and compared to that of complexes 3 and 4, the data for which was previously published. The cyclic voltammograms of the whole complex series were recorded in an aqueous medium (collidine buffer). Their SOD‐like activities were estimated by the McCord–Fridovich test (IC50 with 22 μM cytc FeIII: 1.6 ± 0.1 μMol L–1 for 1, 1.2 ± 0.5 μmol L–1 for 2, 3.0 ± 0.2 μmol L–1 for 3, 3.7 ± 0.6 μmol L–1 for 4, 0.8 ± 0.1 μmol L–1 for 5). IC50 values were converted into the corresponding kinetic constant kMcCF values. A linear correlation between Ea and log(kMcCF) was obtained, indicating that in this series the conversion to MnIII is probably the rate‐limiting step. This is of substantial importance for further Mn–SOD mimic design in this series. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)