We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Remote Oxidative Activation of a [Cp*Rh] Monohydride**.
- Authors
Boyd, Emily A.; Hopkins Leseberg, Julie A.; Cosner, Emma L.; Lionetti, Davide; Henke, Wade C.; Day, Victor W.; Blakemore, James D.
- Abstract
Half‐sandwich rhodium monohydrides are often proposed as intermediates in catalysis, but little is known regarding the redox‐induced reactivity accessible to these species. Herein, the bis(diphenylphosphino)ferrocene (dppf) ligand has been used to explore the reactivity that can be induced when a [Cp*Rh] monohydride undergoes remote (dppf‐centered) oxidation by 1e−. Chemical and electrochemical studies show that one‐electron redox chemistry is accessible to Cp*Rh(dppf), including a unique quasi‐reversible RhII/I process at −0.96 V vs. ferrocenium/ferrocene (Fc+/0). This redox manifold was confirmed by isolation of an uncommon RhII species, [Cp*Rh(dppf)]+, that was characterized by electron paramagnetic resonance (EPR) spectroscopy. Protonation of Cp*Rh(dppf) with anilinium triflate yielded an isolable and inert monohydride, [Cp*Rh(dppf)H]+, and this species was found to undergo a quasireversible electrochemical oxidation at +0.41 V vs. Fc+/0 that corresponds to iron‐centered oxidation in the dppf backbone. Thermochemical analysis predicts that this dppf‐centered oxidation drives a dramatic increase in acidity of the Rh−H moiety by 23 pKa units, a reactivity pattern confirmed by in situ 1H NMR studies. Taken together, these results show that remote oxidation can effectively induce M−H activation and suggest that ligand‐centered redox activity could be an attractive feature for the design of new systems relying on hydride intermediates.
- Subjects
ELECTRON paramagnetic resonance spectroscopy; ELECTRON paramagnetic resonance; PROTON transfer reactions
- Publication
Chemistry - A European Journal, 2022, Vol 28, Issue 13, p1
- ISSN
0947-6539
- Publication type
Article
- DOI
10.1002/chem.202104389