Showing posts with label carbon dioxide;solvent effects;solvolysis;supercritical fluids;sustainable chemistry. Show all posts
Showing posts with label carbon dioxide;solvent effects;solvolysis;supercritical fluids;sustainable chemistry. Show all posts

Tuesday, 10 December 2013

Supercritical Carbon Dioxide: A Promoter of Carbon–Halogen Bond Heterolysis


Thumbnail image of graphical abstract

Angewandte Chemie International Edition

Volume 52Issue 50pages 13298–13301December 9, 2013

Thais Delgado-Abad, Dr. Jaime Martínez-Ferrer, Prof. Dr. Ana Caballero, Dr. Andrea Olmos, Prof. Dr. Rossella Mello, Prof. Dr. María Elena González-Núñez, Prof. Dr. Pedro J. Pérez and Prof. Dr. Gregorio Asensio
Article first published online: 15 OCT 2013 | DOI: 10.1002/anie.201303819

Amazing reaction medium: Supercritical carbon dioxide, with zero dipole moment, lower dielectric constant than pentane, and non-hydrogen-bonding behavior, ionizes carbon–halogen bonds, dissociates the resulting ion pairs, and escapes from capture by the carbocation intermediates at temperatures above 40 °C. These properties allow the observation of carbocation chemistry in the absence of acids.