Proton-Coupled Electron Transfer in the Reduction of Arenes by SmI2–Water Complexes

TitleProton-Coupled Electron Transfer in the Reduction of Arenes by SmI2–Water Complexes
Publication TypeJournal Article
Year of Publication2015
AuthorsChciuk TV, Flowers, II RA
JournalJournal of the American Chemical Society
Volume137
Issue35
Pagination11526-11531
Date Published08/2015
Abstract

The presence of water has a significant impact on the reduction of substrates by SmI2. The reactivity of the Sm(II)-water reducing system and the relationship between sequential or concerted electron-transfer, proton-transfer is not well understood. In this work, we demonstrate that the reduction of an arene by SmI2-water proceeds through an initial proton-coupled electron transfer. The use of thermochemical data available in the literature shows that upon coordination of water to Sm(II) in THF, significant weakening of the O–H bond occurs. The derived value of nearly 73 kcal/mol for the decrease in the bond dissociation energy of the O–H bond in the Sm(II)–water complex is the largest reported to date for low-valent reductants containing bound water.

DOI10.1021/jacs.5b07518