Intramolecular hydrogen bond in alkoxyamines. Influence on the C-ON bond homolysis.
The C-ON bond homolysis in alkoxyamines can be influenced by the presence of an intramolecular hydrogen bond (IHB) between the alkyl and the nitroxyl fragments, which leads to an 8-fold decrease in the homolysis rate constant k(d). When the IHB is disrupted by the solvent or by substitution of the hydrogen involved in the IHB by a protecting group (OMe, OAc, OBz, OBn, or OTBDMS), a higher homolysis rate constant k(d) is observed, as expected from the correlations developed by Marque (Bertin, D.; Gigmes, D.; Marque, S.; Tordo, P. Macromolecules 2005, 38, 2638-2650). Results were confirmed by DFT calculations at the B3LYP/6-31G(d,p) level.
Aix-Marseille Université , CNRS, Institut de Chimie Radicalaire UMR7273, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
Paul
P
Brémond
Teddy
T
Butscher
Valérie
V
Roubaud
Didier
D
Siri
Stéphane
S
Viel