A Stable Coordination Complex of Rh(IV) in an N,O-Donor Environment

A Stable Coordination Complex of Rh(IV) in an N,O-Donor Environment
 
http://pubs.acs.org/doi/abs/10.1021/jacs.5b12148

Shashi B. Sinha, Dimitar Y. Shopov, Liam S. Sharninghausen, David J. Vinyard, Brandon Q. Mercado, Gary W. Brudvig*, and Robert H. Crabtree*
 
Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
 
J. Am. Chem. Soc., Article ASAP
DOI: 10.1021/jacs.5b12148
Publication Date (Web): December 7, 2015
Copyright © 2015 American Chemical Society

Abstract: We describe facial and meridional isomers of [RhIII(pyalk)3], as well as meridional [RhIV(pyalk)3]+ {pyalk =2-(2-pyridyl)-2-propanoate}, the first coordination complex in an N,O-donor environment to show a clean, reversible RhIII/IV redox couple and to have a stable Rh(IV) form, which we characterize by EPR and UV–visible spectroscopy as well as X-ray crystallography. The unprecedented stability of the Rh(IV) species is ascribed to the exceptional donor strength of the ligands, their oxidation resistance, and the meridional coordination geometry.