Benzocyclopropenyl Anion: A Stable 8pi-Electron Species.
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.
Moore
Lenora
L
Departments of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, and Ruder Boskovic Institute, P.O. Box 1016, 41001 Zagreb, Croatia.
Lubinski
Robin
R
Baschky
Michael C.
MC
Dahlke
Gregg D.
GD
Hare
Michael
M
Arrowood
Tina
T
Glasovac
Zoran
Z
Eckert-Maksic
Mirjana
M
Kass
Steven R.
SR