Stable Iridium(IV) Complexes of an Oxidation-Resistant Pyridine-Alkoxide Ligand: Highly Divergent Redox Properties Depending on the Isomeric Form Adopted

Dimitar Y Shopov; Benjamin Rudshteyn; Jesús Campos; Victor S Batista; Robert H Crabtree; Gary W Brudvig

doi:10.1021/jacs.5b04185

Stable Iridium(IV) Complexes of an Oxidation-Resistant Pyridine-Alkoxide Ligand: Highly Divergent Redox Properties Depending on the Isomeric Form Adopted

J Am Chem Soc. 2015 Jun 10;137(22):7243-50. doi: 10.1021/jacs.5b04185. Epub 2015 Jun 1.

Authors

Dimitar Y Shopov¹, Benjamin Rudshteyn¹, Jesús Campos¹, Victor S Batista¹, Robert H Crabtree¹, Gary W Brudvig¹

Affiliation

¹ Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.

PMID: 25988658
DOI: 10.1021/jacs.5b04185

Abstract

The preparation of the facial and meridional isomers of [Ir(pyalk)3] (pyalk = 2-(2-pyridyl)isopropanoate), as model complexes for a powerful water oxidation catalyst, is reported. The strongly donating N3O3 ligand set is very oxidation-resistant, yet promotes facile metal-centered oxidation to form stable Ir(IV) compounds. The Ir(III/IV) reduction potentials of the two isomers differ by 340 mV despite the identical ligand set. A ligand field rationalization is advanced and supported by DFT calculations.