Generation of C6H4+* by laser vaporization of magnesium with o-C6H4F2 in argon carrier gas.
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.
Liu
Haichuan
H
Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Yang
Shihe
S
Balteanu
Iulia
I
Balaj
O Petru
OP
Fox-Beyer
Brigitte S
BS
Beyer
Martin K
MK
Bondybey
Vladimir E
VE