Ground states of molecules. Part XXXII. A MINDO/3 study of mesoionic oxazoles and imidazoles

Abstract

MINDO/3 Calculations are reported for a number of mesoionic species derived from oxazole and imidazole and for isomeric ‘classical’ species. The mesoionic compounds are predicted to be highly polar and much less stable than their classical counterparts. The calculated geometries of the latter correspond to the expected classical structures. Those of the mesoionic compounds on the other hand mostly differ from the structures expected in terms of current treatments of resonance theory.