Late-Stage Modification of Electronic Properties of Antiaromatic and Diradicaloid Indeno[1,2-<i>b</i>]fluorene Analogues via Sulfur Oxidation
Justin J. Dressler, Joshua E. Barker, Lucas J. Karas, Hannah E. Hashimoto, Ryohei Kishi, Lev N. Zakharov, Samantha N. MacMillan, Carlos J. Gómez‐García, Masayoshi Nakano, Judy I. Wu, Michael M. Haley
Abstract
The ability to alter optoelectronic and magnetic properties of molecules at a late stage in their preparation is in general a nontrivial feat. Here, we report the late-stage oxidation of benzothiophene-fused indacenes and dicyclopentanaphthalenes to their corresponding sulfone derivatives. We find that while such modifications increase the highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy gap to a small degree, other properties such as HOMO and LUMO energy levels, molecule paratropicity, and singlet-triplet energy gaps are influenced to a greater degree. The most surprising finding is a change of the bond alternation pattern within the s-indacene core of the sulfones. Computations corroborate the experimental findings and offer plausible explanations for these changes in molecular properties.