Match and Mismatch of Charges in Bifunctional Molecules

The concepts of resonance and charge alternation are nearly synonyms and useful for the description of electron distribution of conjugated % systems bound to heteroatoms [1, 2]. Alternation of the charge along a saturated chain was definitively confirmed by the semiempirical CNDO/2 method [3]. 

When two functional groups with an electronegative heteroatom are present in an organic molecule, a charge alternation can result in their match or mismatch as presented for two oxygen functionalities in Fig. 4.2. 

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