Facile synthesis and complete characterization of homoleptic and heteroleptic cyclometalated Iridium(III) complexes for photocatalysis

• Synthesis of iridium photocatalysts directly from IrCl3 in 1 step and high yields.
• Determination of redox properties.
• Determination of triplet state energies.
• Spectral characterization.

Herein we describe an improved synthesis for homoleptic iridium(III) 2-phenylpyridine based photocatalysts that allows rapid access to these compounds in good to high yields which have recently become a vital component within the field of catalysis. In addition, we synthesized a number of heteroleptic iridium(III) 2-phenylpyridine photocatalysts and report their photophysical and electrochemical properties. The emission energies span the range of 473–560 nm and reduction potentials from −2.27 V to −1.23 V and oxidation potentials ranging from 1.81 V to 0.69 V. Additionally, we provide the calculated excited state properties and comment on the role of these properties in designing catalytic cycles.

The emission energies of the cyclometalated iridium-complexes span the range of 473–560 nm and are shown pictographically by their corresponding color. This range corresponds to a 9 kcal/mol energy difference in available triplet state energy.Figure optionsDownload as PowerPoint slide