Nitroso-naphthol quinone-monooxime tautomeric equilibrium revisited: evidence for oximo group isomerization Original Research Article

An ab initio and DFT treatment of the nitroso-naphthol/quinone-monooxime tautomeric equilibrium revealed that the proton transfer process within the intramolecular hydrogen bond cannot be responsible for the observed doubling of NMR signals. Our analysis demonstrates that the barrier associated with geometric isomerization of the CN bond is the likely cause of the signal doubling phenomenon. The conclusion of our study would suggest the need for re-interpretation of the dynamics in tautomeric equilibria of this type.