One-electron oxidation of [CCOCC]-* in the gas phase forms stable and decomposing forms of CCCCO

Mark Fitzgerald; Suresh Dua; John H Bowie

doi:10.1039/b502458g

One-electron oxidation of [CCOCC]-* in the gas phase forms stable and decomposing forms of CCCCO

Org Biomol Chem. 2005 Jul 21;3(14):2646-51. doi: 10.1039/b502458g. Epub 2005 Jun 17.

Authors

Mark Fitzgerald¹, Suresh Dua, John H Bowie

Affiliation

¹ Department of Chemistry, The University of Adelaide, South Australia 5005.

PMID: 15999200
DOI: 10.1039/b502458g

Abstract

The radical anion [CCOCC]-* may be made in the source of a VG ZAB 2HF mass spectrometer by the reaction between F-(from SF6) and (CH3)3SiC[triple bond]COC[triple bond]CSi(CH3)3. Vertical (Franck-Condon) one-electron oxidation of [CCOCC]-* in the first collision cell produces both singlet and triplet CCOCC. A combination of experiment and molecular modelling (at the CCSD(T)/aug-cc-pVDZ//B3LYP/6-31G* level of theory) gives data which are consistent with the CCOCC neutrals rearranging over small barriers to form singlet and triplet CCCCO in exothermic reactions. Both singlet and triplet CCCCO formed in this way have excess energy. Singlet CCCCO has sufficient excess energy to effect decomposition exclusively to CCC and CO. In contrast, some of the triplet CCCCO neutrals are stable, while others decompose to CCC and CO.