The Raman fingerprint of cyclic conjugation: the case of the stabilization of cations and dications in cycloparaphenylenes
| Autor: | Paul J. Evans, Miklos Kertesz, Valentín G. Baonza, Shigeru Yamago, Ramesh Jasti, M. Carmen Ruiz Delgado, Juan Casado, Mercedes Taravillo, Miriam Peña Alvarez, Juan T. López Navarrete |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Cyclic strain
010405 organic chemistry Chemistry General Chemistry Electronic structure Electron deficiency 010402 general chemistry 01 natural sciences 0104 chemical sciences Ring strain Crystallography symbols.namesake Condensed Matter::Materials Science Computational chemistry Molecular vibration symbols Turning point Density functional theory Physics::Chemical Physics Raman spectroscopy |
| Zdroj: | Pena Alvarez, M, Ruiz Delgado, M C, Taravillo, M, Baonza, V G, Lopez Navarrete, J T, Evans, P, Jasti, R, Yamago, S, Kertesz, M & Casado, J 2016, ' The Raman Fingerprint of Cyclic Conjugation: The case of the Stabilization of Cations and Dications in Cycloparaphenylenes ', Chemical Science . https://doi.org/10.1039/c6sc00765a |
| ISSN: | 2041-6520 |
| Popis: | Radical cations and dications of [n]CPP from n = 5 to n = 12 have been studied by Raman spectroscopy and density functional theory. Small [n]CPP dications owe their stability to the closed-shell electronic structure imposed by cyclic conjugation surpassing the destabilizing effect of ring strain and of the electron deficiency of the charged states. Large [n]CPP dications mitigate cyclic strain by forming diradicals. The Raman spectra reflect the balance among cyclic conjugation, cyclic strain and biradicaloid stabilization by finding an unexpected turning point in the frequency behavior of the G vibrational modes as a function of size. These Raman data represent the vibrational fingerprint of this rare form of conjugation which is central to stabilize both cations and dications of [n]CPP macrocycles. |
| Databáze: | OpenAIRE |
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