The rapid oscillation of a hydrogen atom between the oxygen and nitrogen atoms in a dynamic nitro-ac — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

In the nitro-acinitro system ($-CH_2-NO_2 \rightleftharpoons -CH=NO-OH$), the mobile hydrogen atom migrates from the $\alpha$ -carbon atom (labeled position 3) to the terminal oxygen atom (position 1) across the $N=O$ bond. Because the delocalization of the hydrogen atom happens across a $1 \rightleftharpoons 3$ spatial arrangement, it is classified strictly as a Triad system.