These molecules are characterised by large dipole moments, unsurprisingly, with species (g) outstanding at µ = 9.14 D. Of the five cyclic compounds present none of them appear to be likely candidates for detection since they do not fit the Ellinger criteria. Although there has been a tentative detection of aziridine in hot cores around young stars, the aziridine N-oxide, Fig. , does have an enhanced dipole moment vis-à-vis aziridine which would make it more liable for detection since it yet retains the high symmetry and rigid structure of its parent. However, apart probably from the nitrone, Fig. , which corresponds to Z C-methyl nitrone discussed earlier and whose values are listed in Table , energetically these compounds are unlikely to be of relevance based on our current understanding of conditions in the ISM.