On the paradigm

A survey of the existing experimental and theoretical data on the trinitrogen dioxide anion N 3 O 2 - that manifests a controversy as to the number of isomers and their chemical structures is presented. To resolve the controversy, new computational studies are performed at the MP2/aug-cc-pVTZ computational level. Two hitherto unknown isomers are predicted, one with singlet and one with triplet spin multiplicity. The singlet isomer, structurally characterized as N2 · [ONO]−, is the most stable among all known isomers and accounts for fragmentation patterns observed in the recent dissociative photodetachment experiments.