title: The [12]annulene global minimum.
abstract: A new global minimum for [12]annulene has been computationally located. This mono-trans minimum 5 (CCCCCT) is computed to be 1.5 kcal/mol more stable (CCSD(T)/cc-pVDZ//BHHLYP/6-311+G**) than the known tri-trans isomer 1 (CTCTCT) and 2.4 kcal/mol lower than the di-trans isomer 4 (CCTCCT), for which there is indirect evidence. The barriers for several rearrangements of 5 were all computed to be above 15 kcal/mol, indicating that direct experimental characterization of 5 should be possible. The computed barriers for the dynamic processes (including conformational automerization) coupled with computed 1H NMR shift values should aid in the future characterization of this [12]annulene isomer.
authors.affiliation: Department of Chemistry, University of San Francisco, 2130 Fulton Street, San Francisco, California 94117, USA.
authors.forename: Miles N
authors.initials: MN
authors.lastname: Braten
authors.forename: Claire
authors.initials: C
authors.lastname: Castro
authors.forename: Rainer
authors.initials: R
authors.lastname: Herges
authors.forename: Felix
authors.initials: F
authors.lastname: Köhler
authors.forename: William L
authors.initials: WL
authors.lastname: Karney