CaltechAUTHORS
  A Caltech Library Service

Proton-hydride tautomerism in hydrogen evolution catalysis

Blakemore, James D. and Aguirre Quintana, Luis M. and Johnson, Samantha I. and Winkler, Jay R. and Gray, Harry B. (2016) Proton-hydride tautomerism in hydrogen evolution catalysis. In: 251st American Chemical Society National Meeting & Exposition, March 13-17, 2016, San Diego, CA. https://resolver.caltech.edu/CaltechAUTHORS:20160413-095050455

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20160413-095050455

Abstract

Efficient generation of hydrogen from renewable resources requires development of catalysts that avoid deep wells and high barriers. Information about such features can be obtained by chem. characterization of catalytic intermediates, but few have been obsd. to date. Here, we have mapped the energy landscape of hydrogen evolution in a 2e- + 2H+ reaction sequence by chem. characterization of the intermediate formed upon initial protonation. This intermediate, obtained by treatment of Cp*Rh (bpy) (Cp* = η^5-pentamethylcyclcopentadienyl; bpy = κ^2- 2, 2'- bipyridyl) with acid, is not a hydride species but rather bears [η^4-Cp*H] as a ligand. The preserved Rh^I center can readily be protonated, leading to evolution of H_2 and reformation of η^4-Cp* bound to rhodium(III) . To the best of our knowledge, this is the first direct observation of a proton- relay role for the ubiquitous Cp* ligand, which is revealed here to minimize energy barriers by enabling proton- hydride tautomerism. These low barriers enable reversible catalysis; interconversion of H+ and H_2 can be achieved by minor variation of base concn. in the system. In this presentation, the energy landscape of the system will be discussed, including details from spectroscopic studies of the newly detected intermediate.


Item Type:Conference or Workshop Item (Paper)
Related URLs:
URLURL TypeDescription
http://www.acs.org/content/acs/en/meetings/spring-2016.htmlOrganizationConference Website
ORCID:
AuthorORCID
Blakemore, James D.0000-0003-4172-7460
Winkler, Jay R.0000-0002-4453-9716
Gray, Harry B.0000-0002-7937-7876
Additional Information:© 2016 American Chemical Society.
Record Number:CaltechAUTHORS:20160413-095050455
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20160413-095050455
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:66109
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:13 Apr 2016 17:11
Last Modified:22 Nov 2019 09:58

Repository Staff Only: item control page