Nelson, DJ, Gichuhi, WK, Miller, EM et al. (2 more authors) (2017) Anion Photoelectron Spectroscopy of Deprotonated ortho-, meta-, and para-methylphenol. Journal of Chemical Physics, 146 (7). 074302. ISSN 0021-9606
Abstract
The anion photoelectron spectra of ortho-, meta-, and para-methylphenoxide, as well as methyl deprotonated meta-methylphenol, were measured. Using the Slow Electron Velocity Map Imaging technique, the Electron Affinities (EAs) of the o-, m-, and p-methylphenoxyl radicals were measured as follows: 2.1991±0.0014, 2.2177±0.0014, and 2.1199±0.0014 eV, respectively. The EA of m-methylenephenol was also obtained, 1.024±0.008 eV. In all four cases, the dominant vibrational progressions observed are due to several ring distortion vibrational normal modes that were activated upon photodetachment, leading to vibrational progressions spaced by ∼500 cm−1. Using the methylphenol O–H bond dissociation energies reported by King et al. and revised by Karsili et al., a thermodynamic cycle was constructed and the acidities of the methylphenol isomers were determined as follows: ΔacidH0298K=348.39±0.25, 348.82±0.25, 350.08±0.25, and 349.60±0.25 kcal/mol for cis-ortho-, trans-ortho-, m-, and p-methylphenol, respectively. The excitation energies for the ground doublet state to the lowest excited doublet state electronic transition in o-, m-, and p-methylphenoxyl were also measured as follows: 1.029±0.009, 0.962±0.002, and 1.029±0.009 eV, respectively. In the photoelectron spectra of the neutral excited states, C–O stretching modes were excited in addition to ring distortion modes. Electron autodetachment was observed in the cases of both m- and p-methylphenoxide, with the para isomer showing a lower photon energy onset for this phenomenon.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Authors 2017. The following article appeared in Journal of Chemical Physics 146(7) Article number 074302 on 15 Feb 2017 and may be found at https://doi.org/10.1063/1.4975330. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. |
Keywords: | Excited states; Spectrum analysis; Ground states; Photons; Photoelectron spectra |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Physical Chemistry (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 02 Feb 2017 10:46 |
Last Modified: | 13 Mar 2017 14:16 |
Published Version: | https://doi.org/10.1063/1.4975330 |
Status: | Published |
Publisher: | AIP Publishing |
Identification Number: | 10.1063/1.4975330 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:111507 |