NMR Evidence of Tautomerism for Some 1-Alkyl-3-Aryltriazenes

Abstract

For several 1,3-diaryl- and 1-alkyl-3-aryltriazenes, infraa red evidence of tautomerism I?II has been given;^1,2 in their ir spectra, in fact, these compounds generally show two separate N-H stretching bands. The relative intensities of these bands are influenced by the substituents,^1,2 It was recognized, how ever, that the tautomeric equilibrium constants K_T cannot be determined with accuracy by ir bands intensity measurements as the molar extinction coefficients of forms I and II are not known.¹