title: Synthesis of charged phenyl radicals and biradicals by laser photolysis in a Fourier-transform ion cyclotron resonance mass spectrometer.
abstract: The feasibility of generating substituted phenyl radicals and biradicals (with a charged substituent) in the gas phase by laser photolysis was examined by using a Fourier-transform ion cyclotron resonance mass spectrometer. The precursors were generated by ipso-substitution of a halogen atom in the radical cation of a di- or trihalobenzene by various nucleophiles. Photolytic cleavage of the remaining carbon-halogen bond(s) with 266-nm radiation was found to produce many substituted phenyl radicals in greater yields than the earlier employed method, sustained off-resonance irradiated collision-activated dissociation (SORI-CAD). Furthermore, ion generation by photolysis leads to isomerization less often than collisional activation. Finally, not only phenyl-bromine and phenyl-iodine but also certain phenyl-chlorine bonds can be cleaved by photolysis, whereas the synthetic utility of SORI-CAD appears to be largely limited to the cleavage of phenyl-iodine bonds. Hence, laser photolysis greatly expands the variety of substituted phenyl radicals and biradicals that can be synthesized inside a mass spectrometer.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-1393, USA.
authors.forename: K K
authors.initials: KK
authors.lastname: Thoen
authors.forename: J
authors.initials: J
authors.lastname: Pérez
authors.forename: J J
authors.initials: JJ
authors.lastname: Ferra
authors.forename: H I
authors.initials: HI
authors.lastname: Kenttämaa
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry*; D017357:Cyclotrons; D005583:Fourier Analysis; D005609:Free Radicals; D013058:Mass Spectrometry; D010636:Phenols / Q000737:chemistry*; D010782:Photolysis
chemical_list: D001713:Biphenyl Compounds; D005609:Free Radicals; D010636:Phenols