Untersuchungen über die Struktur von Formazanen I. 15N-H-Kopplung des Chelatwasserstoffatoms

¹⁵N-H-Coupling in 1, 3, 5-triphenylformazan derivatives demonstrates that these compounds are not resonance hybrids but tautomeric pairs. The position of the tautomeric equilibrium is a function of the substituents present in the phenyl nuclei on N-1 and N-5.