Abstract
AbstractHomoaromatic compounds possess an interruptedπsystem but display aromatic properties due to through-space or through-bond interactions. Stable neutral homoaromatic hydrocarbons have remained rare and are typically unstable. Here we present the preparation of a class of stable neutral homoaromatic molecules, supported by experimental evidence (ring current observed by NMR spectroscopy and equalization of bond lengths by X-ray structure analysis) and computational analysis via nucleus-independent chemical shifts (NICS) and anisotropy of the induced current density (ACID). We also show that one homoaromatic hydrocarbon is a photoswitch through a reversible photochemical [1, 11] sigmatropic rearrangement. Our computational analysis suggests that, upon photoswitching, the nature of the homoaromatic state changes in its perimeter from a more pronounced local 6πhomoaromatic state to a global 10πhomoaromatic state. These demonstrations of stable and accessible homoaromatic neutral hydrocarbons and their photoswitching behaviour provide new understanding and insights into the study of homoconjugative interactions in organic molecules, and for the design of new responsive molecular materials.
Funder
Deutsche Forschungsgemeinschaft
Verband der Chemischen Industrie
Publisher
Springer Science and Business Media LLC
Subject
General Chemical Engineering,General Chemistry
Reference66 articles.
1. Williams, R. V. Homoaromaticity. Chem. Rev. 101, 1185–1204 (2001).
2. Cremer, D., Childs, R. F. & Kraka, E. in The Chemistry of the Cyclopropyl Group Vol. 2 (ed. Rappoport, Z.) 339–410 (Wiley, 1995).
3. Childs, R. F., Cremer, D. & Elia, G. in The Chemistry of the Cyclopropyl Group Vol. 2 (ed. Rappoport, Z.) 411–468 (Wiley, 1995).
4. Fernández, I. (ed.). Aromaticity. Modern Computational Methods and Applications (Elsevier, 2021).
5. Winstein, S. Homo-aromatic structures. J. Am. Chem. Soc. 81, 6524–6525 (1959).
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