What Makes Oxidized N-Acylanthranilamides Stable?

J Phys Chem Lett. 2016 Mar 3;7(5):758-64. doi: 10.1021/acs.jpclett.5b02881. Epub 2016 Feb 15.

Abstract

Oligoamides 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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Electrochemical Techniques
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Models, Molecular
  • Oxidation-Reduction
  • ortho-Aminobenzoates / chemistry*

Substances

  • ortho-Aminobenzoates
  • anthranilamide