Gas-Phase Synthesis of the Elusive Cyclooctatetraenyl Radical (C 8 H 7 ) via Triplet Aromatic Cyclooctatetraene (C 8 H 8 ) and Non-Aromatic Cyclooctatriene (C 8 H 8 ) Intermediates

Angew Chem Int Ed Engl. 2017 Oct 23;56(44):13655-13660. doi: 10.1002/anie.201706861. Epub 2017 Sep 22.

Abstract

The 1,2,4,7-cyclooctatetraenyl radical (C8 H7 ) has been synthesized for the very first time via the bimolecular gas-phase reaction of ground-state carbon atoms with 1,3,5-cycloheptatriene (C7 H8 ) on the triplet surface under single-collision conditions. The barrier-less route to the cyclic 1,2,4,7-cyclooctatetraenyl radical accesses exotic reaction intermediates on the triplet surface, which cannot be synthesized via classical organic chemistry methods: the triplet non-aromatic 2,4,6-cyclooctatriene (C8 H8 ) and the triplet aromatic 1,3,5,7-cyclooctatetraene (C8 H8 ). Our approach provides a clean gas-phase synthesis of this hitherto elusive cyclic radical species 1,2,4,7-cyclooctatetraenyl via a single-collision event and opens up a versatile, unconventional path to access this previously largely obscure class of cyclooctatetraenyl radicals, which have been impossible to access through classical synthetic methods.

Keywords: gas-phase chemistry; mass spectrometry; reaction dynamics; reaction intermediates; single-collision conditions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.