Heptagon-Containing Nanographene Embedded into [10]Cycloparaphenylene |
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Authors: | Dr. Juan P. Mora-Fuentes Marcos D. Codesal Marco Reale Dr. Carlos M. Cruz Dr. Vicente G. Jiménez Dr. Alice Sciortino Prof. Marco Cannas Prof. Fabrizio Messina Dr. Victor Blanco Dr. Araceli G. Campaña |
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Affiliation: | 1. Departamento de Química Orgánica and Unidad de Excelencia de Química (UEQ), Facultad de Ciencias, Universidad de Granada, Avda. Fuente Nueva s/n, 18071 Granada, Spain;2. Department of Physics and Chemistry (DiFC) “E. Segrè”, University of Palermo, 90123 Palermo, Italy |
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Abstract: | We report the synthesis and characterization of a novel type of nanohoop, consisting of a cycloparaphenylene derivative incorporating a curved heptagon-containing π-extended polycyclic aromatic hydrocarbon (PAH) unit. We demonstrate that this new macrocycle behaves as a supramolecular receptor of curved π-systems such as fullerenes C60 and C70, with remarkably large binding constants (ca. 107 M−1), as estimated by fluorescence measurements. Nanosecond and femtosecond spectroscopic analysis show that these host-guest complexes are capable of quasi-instantaneous charge separation upon photoexcitation, due to the ultrafast charge transfer from the macrocycle to the complexed fullerene. These results demonstrate saddle-shaped PAHs with dibenzocycloheptatrienone motifs as structural components for new macrocycles displaying molecular receptor abilities and versatile photochemical responses with promising electron-donor properties in host-guest complexes. |
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Keywords: | Cycloparaphenylenes Host-Guest Systems Macrocycles Nanographenes Transient Absorption Spectroscopy |
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