Electrochemistry of iridium-bipyridine complexes

Abstract

Cyclic voltammetry data have been obtained for the bis-, bisesquis-, and tris(2,2'-bipyridine) (bpy) complexes of iridium(II1) in acetonitrile. A reaction mechanism is proposed based on analysis of electrochemical and luminescence data. For the bisesquis and tris complexes the mechanism involves successive one electron transfers producing stable species on an electrochemical time scale. For [Ir(bpy),Clz]+ the electron transfer sequence is interrupted at several steps by the elimination of a chloride. These elimination reactions are time dependent and can be resolved by the variation of the scan rate. The classification of the redox orbitals as localized or delocalized is also discussed.

A Roadmap Towards Visible Light Mediated Electron Transfer Chemistry with Iridium(III) Complexes

“…For IrN 6 complexes (Figure 3), which have no Ir−C bonds, the electron density at the iridium metal center is relatively low, resulting in highly positive oxidation potentials [12b] . Bipyridine‐type ligands exhibit reduction potentials that are typically around −1 V vs .…”

Cell uptake and cytotoxicity of a novel cyclometalated iridium(III) complex and its octaarginine peptide conjugate

“…S2). The complex exhibits a quasi reversible Ir 3+/4+ redox couple centred at +1.70 V versus Ag/AgCl and two quasi-reversible reductions at −0.85 V assigned to the [dfpp] ligand, −1.47 V attributed to the [dfpp] ligand and a further reversible redox peak at −2.09 V attributed to the [picCOOH] ligand versus Ag/AgCl respectively [48]. The anomalous shape and intensity of the −0.85 V wave is consistent with adsorption and is likely to arise due to film formation on the electrode surface as the carboxyl functional group may adsorb to an anodized glassy carbon electrode surface [49].…”

Synthesis, characterization and reactivity of arene ruthenium compounds based on 2,2′-dipyridylamine and di-2-pyridylbenzylamine and their applications in catalytic hydrogen transfer of ketones

“…The position and integrated intensity of various resonances corroborated well to a system involving coordination of respective ligands to the metal centre ruthenium. The assignments are based on splitting patterns and chemical shifts and comparison with the spectra of other d 6 tris(bipyridine) compounds [20]. In the spectra of uncoordinated ligand and the compounds containing dpa, resonances corresponding to acidic amine proton were displayed as a well resolved signal at d 4.00 and wd 11.00 ppm, respectively with respect to aromatic protons.…”