Photoionization of hydroxymethyl (CD[sub 2]OH and CD[sub 2]OD) and methoxy (CD[sub 3]O) radicals. Photoion efficiency spectra, ionization energies, and thermochemistry

Journal Article · Thu Apr 14 00:00:00 EDT 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100066a021· OSTI ID:7267385

Kuo, S C; Zhang, Z; Klemm, R B ^[1]; Liebman, J F ^[2]; Stief, L J ^[3]; Nesbitt, F L ^[4]

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1. Brookhaven National Lab., Upton, NY (United States)
2. Univ. of Maryland, Baltimore, MD (United States)
3. Goddard Space Flight Center, Greenbelt, MD (United States)
4. Goddard Space Flight Center, Greenbelt, MD (United States) Coppin State College, Baltimore, MD (United States)

Photoion efficiency (PIE) spectra were obtained for CD[sub 2]OH, CD[sub 2]OD, and CD[sub 3]O radicals using the discharge flow-photoionization mass spectrometry technique. The radicals were generated in a flow tube via reaction of F atoms with the appropriate methanol isotopomers (CD[sub 3]OH [yields] CD[sub 2]OH, CD[sub 3]OD [yields] CD[sub 2]OD, and CD[sub 3]OH [yields] CD[sub 3]O), which were in large excess. Deuterated methoxy radicals, CD[sub 3]O, were also generated via the reaction of CD[sub 3] with NO[sub 2]. Photoionization of the radicals was achieved using high intensity, dispersed synchrotron radiation, and ionization energies (IE) of these radicals were derived from the thresholds of the PIE spectra: IE(CD[sub 2]OH) = 7.54 [+-] 0.02 eV, IE(CD[sub 2]OD) = 7.53 [+-] 0.02 eV, and IE(CD[sub 3]O) = 10.74 [+-] 0.02 eV. The PIE spectra for CD[sub 2]OH and CD[sub 3]O are compared to those of a previous photoionization study, and differences are discussed. Integration of previously published photoelectron spectroscopy data for CD[sub 2]OH yields a curve quite similar to our PIE spectrum. Empirical estimates of IE(CH[sub 2]OH) and IE(CH[sub 3]O) are given to corroborate our assignments. The measured ionization energies and the derived thermodynamic quantities are compared with previously reported results. 67 refs., 7 figs., 2 tabs.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7267385
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 98:15; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CHEMICAL BONDS
DISSOCIATION
METHOXY RADICALS
FORMATION HEAT
MASS SPECTRA
PHOTOIONIZATION
RADICALS
DEUTERIUM COMPOUNDS
METHANOL
METHYL RADICALS
SYNCHROTRON RADIATION
THERMOCHEMICAL PROCESSES
THERMODYNAMICS
ALCOHOLS
ALKOXY RADICALS
ALKYL RADICALS
BREMSSTRAHLUNG
ELECTROMAGNETIC RADIATION
ENTHALPY
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
IONIZATION
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
RADIATIONS
REACTION HEAT
SPECTRA
THERMODYNAMIC PROPERTIES
400201* - Chemical & Physicochemical Properties
400500 - Photochemistry