Observation of temperature-dependent 1H nuclear magnetic resonance spectra for aziridine and [N-2H]aziridine in the gas phase

Abstract

The n.m.r. spectra of the methylene protons in aziridine and [N-²H]aziridine have been obtained in the gas phase at 35 °C by means of Fourier transform spectroscopy at 100 MHz, and it is found that as the temperature is raised, a ‘coalescence point’ is observed at 68 °C, corresponding to a free energy of activation (ΔG_c^‡) of 17·3 kcal/mol (72·4 kJ/mol); the coalescence temperature in the case of [N-²H]aziridine is 79 °C, corresponding to a ΔG_c^‡ value of 17·9 kcal/mol (74·9 kJ/mol).