A discharge flow-photoionization mass spectrometric study of the FO(X 2Πi) radical: Photoionization efficiency spectrum and ionization energy

✍ Scribed by Zhengyu Zhang; Szu-Cherng Kuo; R.Bruce Klemm; Paul S. Monks; Louis J. Stief

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 481 KB
• Volume: 229
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(94)01064-1

✦ Synopsis

Photoionization efficiency spectra of FO were measured over the wavelength range 80.0-100.0 nm and in the ionization threshold region, 94.0-100.0 nm, using a discharge flow-photoionization mass spectrometer apparatus coupled to a synchrotron radiation source, FO was generated by the reaction of F( 'P) atoms with NO, and via a F,/OZ discharge. A value of 12.78 f 0.03 eV was obtained for the adiabatic ionization energy of FO from photoion thresholds which corresponds to FO+ (X 'C-) +FO( X 'II,). These results, which are the first to be obtained by direct PIMS measurements, corroborate those of a photoelectron spectroscopy study; however, the ionization energy determined here is free from interferences due to other species which complicated the PES measurement. A value of 109.5 f 8.0 kJ mol-' for ArH& (FO) is computed from the present value of IE(F0) and a previous appearance energy measurement, and a value for the proton affinity of FO is calculated to be 511.5~10.0kJmol-'.