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Updated: Jul 5, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Gas-phase carbene radical anions: new mechanistic insights
Stephanie M Villano1, Nicole Eyet, W Carl Lineberger
1JILA, University of Colorado and the National Institute of Standards and Technology and the University of Colorado, Department of Chemistry and Biochemistry, 215 UCB, Boulder, Colorado 80309-0215, USA.
Abstract:
The gas-phase reactivity of the CHCl*- anion has been investigated with a series of halomethanes (CCl4, CHCl3, CH2Cl2, and CH3Cl) using a FA-SIFT instrument. Results show that this anion primarily reacts via substitution and by proton transfer. In addition, the reactions of CHCl*- with CHCl3 and CH2Cl2 form minor amounts of Cl2*- and Cl-. The isotopic distribution of these two products is consistent with an insertion-elimination mechanism, where the anion inserts into a C-Cl bond to form an unstable intermediate, which eliminates either Cl2*- or Cl- and Cl*. Neutral and cationic carbenes are known to insert into single bonds; however, this is the first observation of such reactivity for carbene anions.
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