Photoionization efficiency spectrum, ionization energy, and heat of formation of Br{sub 2}O

Journal Article · Thu Jul 25 04:00:00 EDT 1996 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/jp960405z· OSTI ID:380805

Thorn, Jr, R P; Monks, P S; Stief, L J ^[1]; Kuo, S C; Zhang, Z; Klemm, R B ^[2]

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1. NASA/Goddard Space Flight Center, Greenbelt, MD (United States)
2. Brookhaven National Lab., Upton, NY (United States)

The photoionization efficiency (PIE) spectrum of Br{sub 2}O was measured over the wavelength range {lambda} = 100-125 nm by using a photoionization mass spectrometer apparatus coupled to a synchrotron radiation source. A value of 10.26{sub 4}{+-}0.01{sub 1} eV was obtained for the adiabatic ionization energy of Br{sub 2}O from analysis of the photoionization thresholds. Also, the appearance energy (AE) of BrO{sup +} (from the dissociative ionization of Br{sub 2}O) was determined from the PIE spectrum of BrO{sup +} over the wavelength range {lambda} = 104-110 nm. Combining the AE{sub 298} value, 11.71{sub 4}{+-}0.01{sub 4} eV, with known thermodynamic quantities yields a value for {Delta}{sub f}H{degree}{sub 298}(Br{sub 2}O) = 107.1{+-}3.5 kJ mol{sup -1}. The value for {Delta}{sub f}H{degree}{sub 298}(Br{sub 2}O) may be related to {Delta}{sub f}H{degree}{sub 298}(HOBr) through the equilibrium constant for the reaction Br{sub 2}O + H{sub 2}O 2HOBr. This leads to {Delta}{sub f}H{degree}{sub 298}(HOBr) = -60.0{+-}3.5 kJ mol{sub -1}. 33 refs., 5 figs., 2 tabs.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 380805
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 30 Vol. 100; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ABSORPTION SPECTRA
BINDING ENERGY
BROMINE OXIDES
EFFICIENCY
FORMATION HEAT
IONIZATION POTENTIAL
PHOTOIONIZATION
THERMODYNAMICS