title: Vacuum-UV negative photoion spectroscopy of SF5CF3.
abstract: Ion pair formation, generically described as AB-->A(+)+B(-), from vacuum-UV photoexcitation of trifluoromethyl sulfur pentafluoride, SF(5)CF(3), has been studied by anion mass spectrometry using synchrotron radiation in the photon energy range of 10-35 eV. The anions F(-), F(2)(-), and SF(x)(-) (x=1-5) are observed. With the exception of SF(5)(-), the anions observed show a linear dependence of signal with pressure, showing that they arise from ion pair formation. SF(5)(-) arises from dissociative electron attachment, following photoionization of SF(5)CF(3) as the source of low-energy electrons. Cross sections for anion production are put on to an absolute scale by calibration of the signal strengths with those of F(-) from both SF(6) and CF(4). Quantum yields for anion production from SF(5)CF(3), spanning the range of 10(-7)-10(-4), are obtained using vacuum-UV absorption cross sections. Unlike SF(6) and CF(4), the quantum yield for F(-) production from SF(5)CF(3) increases above the onset of photoionization.
authors: School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
authors: M J
authors: MJ
authors: Simpson
authors: R P
authors: RP
authors: Tuckett
authors: K F
authors: KF
authors: Dunn
authors: C A
authors: CA
authors: Hunniford
authors: C J
authors: CJ
authors: Latimer
authors: S W J
authors: SW
authors: Scully