jz5b02881_si_001.pdf (623.02 kB)
What Makes Oxidized N‑Acylanthranilamides Stable?
journal contribution
posted on 2016-02-10, 00:00 authored by Eli M. Espinoza, Jillian
M. Larsen, Valentine I. VullevOligoamides
composed of anthranilic acid derivatives present a
promising choice for mediating long-range charge transfer and controlling
its directionality. Hole hopping, modulated by the anthranilamide
(Aa) permanent dipoles, provides a plausible means for such rectified
long-range charge transduction. All aliphatic and most aromatic amides,
however, decompose upon oxidation, rendering them unacceptable for
hole-hopping pathways. We, therefore, employ electrochemical and computational
analysis to examine how to suppress oxidative degradation and stabilize
the radical cations of N-acylated Aa derivatives.
Our findings reveal two requirements for attaining long-lived radical
cations of these aromatic amides: (1) keeping the reduction potentials
for oxidizing the Aa residues under about 1.4 V vs SCE and (2) adding
an electron-donating group para to the N-terminal amide of the aromatic
ring, which prevents the electron spin density of the radical cation
from extending over the C-terminal amide. These findings provide essential
information for the design of hole-transfer amides.