Journal of the American Chemical Society
Communication
(22) Furthermore, DFT calculations predicted that log A = 6.9 for
the reaction of diphenylamine with iso-propylperoxyl radical (see
Figure 2).
(23) DiLabio, G. A.; Johnson, E. R. J. Am. Chem. Soc. 2007, 129,
6199−6203.
(24) Valgimigli, L.; Amorati, R.; Petrucci, S.; Pedulli, G. F.; Hu, D.;
Hanthorn, J. J.; Pratt, D. A. Angew. Chem., Int. Ed. 2009, 48, 8348−
8351.
(25) Diphenylamine has a gas-phase ionization energy of 7.19 eV,
while that for p-methylphenol, whose O−H BDE is essentially the
same as the N−H BDE in diphenylamine, is 8.34 eV. See: Lias, S. G.
In NIST Chemistry WebBook; Linstrom, P. J.; Mallard, W. G., Eds.;
NIST Standard Reference Database 69; National Institute of Standards
and Technology: Gaithersburg, MD.
(26) Jensen, R. K.; Korcek, S.; Zinbo, M.; Gerlock, J. L. J. Org. Chem.
1995, 60, 5396−5400. We recently presented an alternative (see:
Amorati, R.; Pedulli, G. F.; Pratt, D. A.; Valgimigli, L. Chem. Commun.
2010, 46, 5139−5141 ). The greater access to stable but electronically
distinct diarylamines described here should aid in the design of
experiments aimed at distinguishing which mechanism is responsible
for this highly relevant catalytic activity.
those of the best phenolic antioxidantssuggesting that they will
be useful in a far broader range of applications. This is currently
under more detailed investigation.
ASSOCIATED CONTENT
■
S
* Supporting Information
Complete characterization data for amines 3−16 and
experimental data for peroxyl radical kinetics, electrochemical,
and EPR studies. This material is available free of charge via the
AUTHOR INFORMATION
■
Corresponding Author
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We are grateful for the support of NSERC of Canada, the
Ontario Ministry of Research and Innovation, and the Canada
Research Chairs Program for grants to D.A.P. and to the MIUR
(Rome) and the University of Bologna for grants to L.V.
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