Datensatz

Zusammenfassung

Electron-transfer series are described for three ferric complexes of the pentadentate ligand 4,8,11-trimethyl-1,4,8,11-tetraazacyclotetradecane-1-acetate (Me₃cyclam−acetate) with axial chloride, fluoride, and azide ligands. These complexes can all be reduced coulometrically to their Fe(II) analogs and oxidized reversibly to the corresponding Fe(IV) species. The Fe(II), Fe(III), and Fe(IV) species have been studied spectroscopically and their UV−vis, Mössbauer, EPR, and IR spectra are presented. The fluoro species [(Me₃cyclam−acetate)FeF]ⁿ⁺ (n = 0, 1, 2) have been studied computationally using density functional theory (DFT), and the electronic structure of the Fe(IV) dication [(Me₃cyclam−acetate)FeF]²⁺ is compared with that of the isoelectronic Fe(IV) oxo cation [(Me₃cyclam−acetate)FeO]⁺; the different properties of the two species are mainly due to the significantly covalent Fe=O π bonds in the latter.