Spectroelectrochemistry of iron complexes of the C₂-capped porphyrin ligand

The coordination chemistry of iron complexes of C₂-capped porphyrin ligand has been examined by spectroelectrochemistry. In solution, in dimethylsulphoxide (DMSO), the chloride ion of [Fe¹¹¹(C₂cap)Cl] remained bound to iron(III). In the presence of 1-methylimidazole (1-MeIm) the Cl^- ion is substituted by OH^-, generated by reaction of 1-MeIm with trace amounts of water in the system. Controlled potential reduction of [Fe¹¹¹(C₂cap)(OH)] in DMSO solution produced the six-coordinate iron(II) complex [Fe¹¹(C₂cap)(1-MeIm)(DMSO)], with the DMSO ligand bound within the capping group. Reduction of [Fe¹¹¹(C₂cap)Cl], in solution in CH₂Cl₂ containing 1-MeIm, produced the five coordinate iron(II) species, Fe¹¹(C₂cap)(1-MeIm). © 1993.