Iridium-based complexes for water oxidation.

Anodic deposition of a robust iridium-based water-oxidation catalyst from organometallic precursors†

Artificial photosynthesis, modeled on natural light-driven oxidation of water in Photosystem II, holds promise as a sustainable source of reducing equivalents for producing fuels. Few robust wateroxidation catalysts capable of mediating this difficult four-electron, four-proton reaction have yet been described. We report a new method for generating an amorphous electrodeposited material, princi...

Cyclometalated iridium(III) Aquo complexes: efficient and tunable catalysts for the homogeneous oxidation of water.

A series of bis-phenylpyridine, bis-aquo iridium(III) complexes is herein shown to robustly and efficiently catalyze the oxidation of water to dioxygen in the presence of a sacrificial oxidant. Through substitution on the cyclometalating ligands of these complexes, it is shown that a broad range of oxidation potentials can be achieved within this class of catalyst. Parallel, dynamic monitoring ...

Cyclometalated cinchophen ligands on iridium(III): towards water-soluble complexes with visible luminescence.

Eight cationic heteroleptic iridium(III) complexes, [Ir(epqc)2(N^N)](+), were prepared in high yield from a cyclometalated iridium bridged-chloride dimer bearing two ethyl-2-phenylquinoline-4-carboxylate (epqc) ligands. Two X-ray crystallographic studies were undertaken on selected complexes (where the ancillary ligand N^N = 4,4'-dimethyl-2,2'-bipyridine and 4,7-diphenyl-1,10-phenanthroline) ea...

Characterization of an amorphous iridium water-oxidation catalyst electrodeposited from organometallic precursors.

Upon electrochemical oxidation of the precursor complexes [Cp*Ir(H(2)O)(3)]SO(4) (1) or [(Cp*Ir)(2)(OH)(3)]OH (2) (Cp* = pentamethylcyclopentadienyl), a blue layer of amorphous iridium oxide containing a carbon admixture (BL) is deposited onto the anode. The solid-state, amorphous iridium oxide material that is formed from the molecular precursors is significantly more active for water-oxidatio...

Water oxidation catalyzed by strong carbene-type donor-ligand complexes of iridium.