Why do cycloaddition reactions involving C60 prefer [6,6] over [5,6] bonds?

The origin of the experimentally known preference for [6,6] over [5,6] bonds in cycloaddition reactions involving C60 has been computationally explored. To this end, the Diels-Alder reaction between cyclopentadiene and C60 has been analysed by means of the recently introduced activation strain model...

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Detalles Bibliográficos
Autores: Fenández López, Israel, Solà i Puig, Miquel, Bickelhaupt, F. Matthias
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10256/11433
Acceso en línea:http://hdl.handle.net/10256/11433
Access Level:acceso embargado
Palabra clave:Reaccions d'addició
Addition reactions
Funcional de densitat, Teoria del
Density functionals
Diels-Alder, Reacció de
Diels-Alder reaction
Fullerenes
Ful·lerens
Ciclització (Química)
Ring formation (Chemistry)
Descripción
Sumario:The origin of the experimentally known preference for [6,6] over [5,6] bonds in cycloaddition reactions involving C60 has been computationally explored. To this end, the Diels-Alder reaction between cyclopentadiene and C60 has been analysed by means of the recently introduced activation strain model of reactivity in combination with the energy decomposition analysis method. Other issues, such as the aromaticity of the corresponding transition states, have also been considered. These results indicate that the major factor controlling the observed regioselectivity is the more stabilising interaction between the deformed reactants in the [6,6] reaction pathway along the entire reaction coordinate. Why [6,6]? The preference for [6,6] over [5,6] bonds in cycloaddition reactions involving C60 is experimentally well-established (see figure). However, the reasons (i.e., physical factors) behind this preference are so far completely unknown. By means of the recently introduced activation strain model of reactivity in combination with the energy decomposition analysis method, a definite answer to the question in the title is provided