Factors Affecting Stability and Equilibria of Free Radicals, XVII+ EPR Evidence for Formation of N-Alkoxypicramides on Oxidation of N-Alkoxy-dinitroanilines. Electronic Structure of Aminyl Radicals

Abstract

Oxidation of N-alkoxy-2,6- or -2,4-dinitroanilines with various oxidizing agents yields the corresponding N-alkoxydinitrophenyl-aminyls, which then undergo spontaneous conversion into the corresponding N-alkoxy-2,4,6-trinitrophenyl-aminyls. The EPR spectra of all these persistent aminyls are presented and discussed. Such disproportionations did not occur in capto-dative diaryl-aminyls which had lower spin densities on the electron-acceptor group than the present N–alkoxy-polynitrophenyl-aminyls (these have, in addition. Ν—Ο bonds which are less strong than N—C bonds). Electronic structures of diaryl-aminyls and N-alkoxy-aryl-aminyls are discussed: both are π-radicals, but they probably possess at the nitrogen atom an approximately linear, and a kinked structure, respectively.