How do HeteroatomPlacements Affect the Paratropicitiesof Heteroaromatic-Fused Indacenes?

Topological charge stabilization rules explain how heteroatom placements in heteroaromatic-fused <i>s</i>-indacenes (ID) and dicyclopenta[<i>b</i>,<i>g</i>]naphthalenes (IID) modulate the paratropicities of the [4<i>n</i>] core. Nucleus-independent chemical shifts (NICS)-XY scans, natural bond orbital analyses, and computed HOMO–LUMO gaps rationalize the antiaromaticity orders of symmetrically and nonsymmetrically benzoheteroaromatic fused IDs and IIDs containing π-electron-rich and π-electron-deficient heteroatoms.