ABSTRACT
The TRE model was independently introduced by Aihara [101,109] and it Is presently used by several research groups [110-115]. However, with the increasing use of the TRE model, criticisms of it (some justified and some not) have also increased [116-118]. It appears that the majority of these critical remarks (non-physical reference structure, unacceptably large values c i TRE indices for radicals, ions, radical-ions, etc.) are really criticisms of all DRE-like resonance energy indices and not only TRE, because it has been shown by several people that DRE, REPE, and TRE are strongly related aromaticity indices [4]. Nevertheless, it is clear that the TRE model must undergo a major revision in order to be applicable to all kinds of conjugated systems. Work in this direction is in progress.
