File:Chapter 9 - INNOVATIVE METHODS FOR THE PREDICTION OF AROMATIC, ANTI-AROMATIC AND NON AROMATIC BEHAVIOUR OF HETEROCYCLIC COMPOUNDS pp 92-109.pdf

In this chapter, formulae-based mnemonics have been highlighted by classifying the lone pair of electrons (localized or delocalized) in an innovative and time economic way. Here, I have tried to hub two (02) time economic mnemonics by including two (02) formulae for the prediction of aromatic and antiaromatic behavior of heterocyclic compounds. This chapter includes innovative formulae involving calculation of ‘A' value by just manipulating the no of π bonds within the ring system and delocalized lone pair electron (DLP) with one (01). The heterocyclic compound having cyclic, planar, conjugated with an even number of ‘A' value will be treated as aromatic in nature and with an odd number of ‘A' value will be treated as an antiaromatic in nature. In case of a multi hetero atom based heterocyclic compound, containing both delocalized lone pair electron (DLP) and localized lone pair electron (LLP) based heteroatoms, Aromatic and Anti Aromatic behavior should be predicted with respect to DLP based hetero atom only. But when heterocyclic compounds contain both LLP based hetero atoms then Aromaticity should be predicted with respect to that heteroatom which contains the lowest possible position number as per IUPAC nomenclature or any one of the heteroatom.