title: Manifestations of Bridgehead-Bridgehead Interactions in the Bicyclo[1.1.1]pentane Ring System.
abstract: A series of 3-halo-substituted bicyclo[1.1.1]pentane-1-carboxylic acids 1 (Y = COOH; X = F, Cl, Br, I, and CF(3)) as well as the parent compound 1 (Y = COOH, X = H) have been prepared, and a study of some of their properties have been made. It was found that their reactions with xenon difluoride cover a wide range of reactivities. On one hand, the fluoro acid 1 (Y = COOH, X = F) displayed no apparent reaction at all while, on the other, the bromo acid 1 (Y = COOH, X = Br) and parent compound 1 (Y = COOH, X = H) underwent ready reaction with complete disintegration of the ring system. A possible explanation is advanced based on polar kinetic and thermodynamic effects governing the lifetime of an intermediate acyloxy radical species. The relative ease of oxidation of the carboxylates 1 (Y = COO(-); X = H, F, Cl, Br, I, CF(3), and COOCH(3)), as mirrored by their peak oxidation potential values (E(p)) determined by cyclic voltammetry, also covers a wide range. These data coupled with the dissociation constants (pK(a)) of some of the acids 1 (Y = COOH; X = H, F, Cl, and CF(3)) reflect significantly on the modes of transmission of electronic effects acting through the bicyclo[1.1.1]pentane ring system.
authors.affiliation: Department of Chemistry, The Flinders University of South Australia, Adelaide, Australia, 5001, Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Department of Chemical Sciences, Deakin University, Geelong, Victoria, Australia 3217, Laboratoire a' Electrochimie Moléculaire de L'Université Denis Diderot (Paris 7), 2 place Jussieu, 75251 Paris Cedex 05, France, and Institute of Chemical Technology, Prague, Czech Republic.
authors.forename: William
authors.initials: W
authors.lastname: Adcock
authors.forename: Andrei V.
authors.initials: AV
authors.lastname: Blokhin
authors.forename: Gordon M.
authors.initials: GM
authors.lastname: Elsey
authors.forename: Nicholas H.
authors.initials: NH
authors.lastname: Head
authors.forename: Alexander R.
authors.initials: AR
authors.lastname: Krstic
authors.forename: Michael D.
authors.initials: MD
authors.lastname: Levin
authors.forename: Josef
authors.initials: J
authors.lastname: Michl
authors.forename: Jamie
authors.initials: J
authors.lastname: Munton
authors.forename: Evgueni
authors.initials: E
authors.lastname: Pinkhassik
authors.forename: Marc
authors.initials: M
authors.lastname: Robert
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Savéant
authors.forename: Alexander
authors.initials: A
authors.lastname: Shtarev
authors.forename: Ivan
authors.initials: I
authors.lastname: Stibor