Photoionization Efficiency Spectrum And Ionization Energy of Obro

Published

November 1, 1999

Author(s)

R P. Thorn, L J. Stief, T J. Buckley, Russell D. Johnson III, P S. Monks, R B. Klemm

Abstract

The photoionization efficiency (PIE) spectrum of OBrO was measured over the wavelength range [Lambda] = 86 - 126 nm by using a discharge flow-photoionization mass spectrometer (DF-PIMS) apparatus coupled to a VUV synchrotron radiation source. Bromine dioxide was generated in a flow tube reactor by first forming BrO via the reaction O(³P) + Br₂ and then allowing the BrO to react on the cold flow tube wall. The PIE spectrum of the BrO reactant was obtained and the photoionization threshold evaluated from the half-rise point of the step at threshold. This re-measurement yields IE(BrO) = 10.48 0.02 eV, which supersedes our previous result. The PIE spectrum of OBrO displayed step-like behavior near threshold. A value of 10.29 0.03 eV was obtained for the adiabatic ionization energy (IE) of OBrO from analysis of the photoionization threshold at [Lambda] = 120.5 nm. An ab initio determination of the IE of OBrO using the CCSD(T)/6 311+G(3df)//CCD/6 311+G(3df) level of theory gives a value of 10.26 0.06 eV, which is in good agreement with the experimental result. These results are compared with previous determinations of the IE for both halogen monoxides, XO, and halogen dioxides, OXO (X = Cl, Br, I).

Citation

Journal of Physical Chemistry

Volume

103

Issue

No. 42

Pub Type

Journals

Keywords

ab initio, ionization energy, mass spectroscopy, OBrO, photoionization spectroscopy

Citation

Thorn, R. , Stief, L. , Buckley, T. , Johnson III, R. , Monks, P. and Klemm, R. (1999), Photoionization Efficiency Spectrum And Ionization Energy of Obro, Journal of Physical Chemistry (Accessed October 28, 2025)