Enhancing the cumulene character of one‐dimensional acetylene‐based systems by stimuli‐induced planarization of their two pro‐diradicaloid cyclopenta[h,i]aceanthrylene units
Acetylene/polyynes (C≡C)n and cumulenes =(C=)n are connectors widely used for the realization of one-dimensional (1D) π-conjugates. Although both π-moieties are constituted by sp carbon atoms, their different bond connectivity confers distinct physicochemical properties to the resulting systems. In...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/716574 |
| Acceso en línea: | http://hdl.handle.net/10486/716574 https://dx.doi.org/10.1002/anie.202419832 |
| Access Level: | acceso abierto |
| Palabra clave: | Acetylene Cooperative Supramolecular Polymerization Cyclopenta[h,i]aceanthrylene Cumulene Pro-diradicaloid Species Química |
| Sumario: | Acetylene/polyynes (C≡C)n and cumulenes =(C=)n are connectors widely used for the realization of one-dimensional (1D) π-conjugates. Although both π-moieties are constituted by sp carbon atoms, their different bond connectivity confers distinct physicochemical properties to the resulting systems. In this context, while many acetylene/polyyne- and cumulene-based derivatives have been prepared and studied, no reports have tackled the possibility to reversibly alter the acetylene/polyyne-cumulene electronic character of these derivatives using mild conditions. Herein, we present a novel approach to enhance the cumulene character of 1D acetylene-based conjugates consisting in the preparation of derivatives featuring an acetylene moiety connecting two pro-diradicaloid species, namely cyclopenta-[h,i]aceanthrylene (CPA), at their pro-radical positions. A thoughtful spectroscopic study of the prepared dimers, complemented by theoretical calculations, suggest a high π-electronic delocalization of the pro-diradicaloid CPAs through the central acetylene spacer upon the dimers’ planarization which, in turn, increases the cumulenic character of the acetylenic π-bridge, a feature enhanced for one of the two dimers at low temperature and in methylcyclohexane due to an aggregation-induced planarization process. We reckon that the proposed approach offers an interesting avenue towards the realization of 1D systems which cumulenic character of the acetylenic π-connector could be altered in response to external stimuli |
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