title: Generation of C6H4+* by laser vaporization of magnesium with o-C6H4F2 in argon carrier gas.
abstract: A route to efficient generation of C6H4+*, potentially the benzyne radical cation, is presented. Laser vaporization of Mg+* and supersonic expansion in helium doped with o-, m-, or p-C6H4F2 yields, among other ions, o-, m-, p-C6H4F2Mg+* complexes, but no C6H4+*. Collision-induced dissociation experiments show that the o-C6H4F2Mg+* complex can be converted into C6H4+* in a mildly energetic collision, with a center-of-mass energy around 1-2 eV. These conditions can also be reached in the ion source when argon is used as a carrier gas. In this way, mass spectra containing the desired m/z 76 peak, i.e. C6H4+*, are obtained.
authors.affiliation: Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Haichuan
authors.initials: H
authors.lastname: Liu
authors.forename: Shihe
authors.initials: S
authors.lastname: Yang
authors.forename: Iulia
authors.initials: I
authors.lastname: Balteanu
authors.forename: O Petru
authors.initials: OP
authors.lastname: Balaj
authors.forename: Brigitte S
authors.initials: BS
authors.lastname: Fox-Beyer
authors.forename: Martin K
authors.initials: MK
authors.lastname: Beyer
authors.forename: Vladimir E
authors.initials: VE
authors.lastname: Bondybey