The molecules we have studied here are all highly (quasi-)symmetric, as the small substituents we use only slightly perturb the symmetry of the molecular cores. This severely limits the oscillator strengths of the S 1 transition because the HOMO-LUMO overlap is small. Listed in Table and S5, none of the molecules achieve appreciable oscillator strengths from S 1 , although some of the molecules are not far from potentially being in an experimentally measurable range. Consequently, many of them may not obey Kasha's rule, as is the case for s-indacene, azulene and pyrene. However, larger substituents were found to yield higher oscillator strenghts in otherwise highly symmetric azaphenalenes. In the previously-identified cases of azupyrene and bicalicene (Figure ), the requisite symmetry was induced by precise polycyclic push-pull ring motifs. The structures described here correspond to a much simpler, robust and transferable design rule: the alleviation of antiaromaticity and concommitant double-bond delocalization through substituent effects (Figure ). The scope and conceptual simplicity of this approach provide reason for optimism that perhaps larger substituents will be able to induce the same double-bond delocalization while enabling optically useful oscillator strengths.