title: Benzocyclopropenyl Anion: A Stable 8pi-Electron Species.
abstract: The conjugate base of benzocyclopropene has been generated in the gas phase. Its reactivity and thermodynamic stability were explored. The measured acidity is DeltaH degrees (acid)(benzocyclopropene) = 386 +/- 3 kcal/mol, and the electron affinity of benzocyclopropenyl radical is 0.51 eV < EA < 1.11 eV. Ab initio calculations satisfactorily reproduce the experimental results and provide additional insights. Benzocyclopropene is found to be 34.5 kcal/mol more acidic than the allylic position of cyclopropene and only 4 +/- 3 kcal/mol less acidic than toluene. These findings are explained in terms of the structure and electronic properties of benzocyclopropenyl anion.
authors.affiliation: Departments of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, and Ruder Boskovic Institute, P.O. Box 1016, 41001 Zagreb, Croatia.
authors.forename: Lenora
authors.initials: L
authors.lastname: Moore
authors.forename: Robin
authors.initials: R
authors.lastname: Lubinski
authors.forename: Michael C.
authors.initials: MC
authors.lastname: Baschky
authors.forename: Gregg D.
authors.initials: GD
authors.lastname: Dahlke
authors.forename: Michael
authors.initials: M
authors.lastname: Hare
authors.forename: Tina
authors.initials: T
authors.lastname: Arrowood
authors.forename: Zoran
authors.initials: Z
authors.lastname: Glasovac
authors.forename: Mirjana
authors.initials: M
authors.lastname: Eckert-Maksic
authors.forename: Steven R.
authors.initials: SR
authors.lastname: Kass