Determination of the Electron Affinity of the Acetyloxyl Radical (CH3COO) by Low-Temperature Anion Photoelectron Spectroscopy and ab Initio Calculations

Journal Article · Thu Apr 20 04:00:00 EDT 2006 · Journal of Physical Chemistry A, 110(15):5047-5050

DOI:https://doi.org/10.1021/jp060138p· OSTI ID:882969

Wang, Xue B; Woo, Hin-koon; Wang, Lai S; Minofar, Babak; Jungwirth, Pavel

The electronic structure and electron affinity of the acetyloxyl radical (CH3COO) were investigated by low-temperature anion photoelectron spectroscopy and ab initio calculations. Photoelectron spectra of the acetate anion (CH3COO-) were obtained at two photon energies (355 and 266 nm) and under three different temperatures (300, 70, and 20 K) using a new low temperature ion-trap photoelectron spectroscopy apparatus. In contrast to a featureless spectrum at 300 K, a well-resolved vibrational progression corresponding to the OCO bending mode was observed at low temperatures in the 355 nm spectrum, yielding an accurate electron affinity for the acetyloxyl radical as 3.250 + 0.010 eV. This experimental result is supported by ab initio calculations, which also indicate three low-lying electronic states observed in the 266 nm spectrum. The calculations suggest a 19° decrease of the OCO angle upon detaching an electron from acetate, consistent with the vibrational progression observed experimentally.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 882969
• Report Number(s): PNNL-SA-49177; 3223; KC0301020
• Journal Information: Journal of Physical Chemistry A, 110(15):5047-5050, Journal Name: Journal of Physical Chemistry A, 110(15):5047-5050
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory