Charge distribution and aromaticity in protonated urazole

Abstract

Urazol was reacted in various superacidic media, its` mono- and diprotonated species were isolated and characterized by Raman and NMR spectroscopy as well as single crystal X-ray structure determination. Quantum chemical calculations are employed to characterize charge localization with Mapped Electrostatic Potentials and NPA charges. NICS(0) is calculated to evaluate aromatic character of urazole and its` cations. The results are used to compare the protonation of urazole to that of parabanic acid.