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Title: High-resolution photoelectron imaging spectroscopy of cryogenically cooled Fe{sub 4}O{sup −} and Fe{sub 5}O{sup −}

Abstract

We report high-resolution photodetachment spectra of the cryogenically cooled iron monoxide clusters Fe{sub 4}O{sup −} and Fe{sub 5}O{sup −} obtained with slow photoelectron velocity-map imaging (cryo-SEVI). Well-resolved vibrational progressions are observed in both sets of spectra, and transitions to low-lying excited states of both species are seen. In order to identify the structural isomers, electronic states, and vibrational modes that contribute to the cryo-SEVI spectra of these clusters, experimental results are compared with density functional theory calculations and Franck-Condon simulations. The main bands observed in the SEVI spectra are assigned to the {sup 15}A{sub 2}←{sup 16}B{sub 2} photodetachment transition of Fe{sub 4}O{sup −} and the {sup 17}A′←{sup 18}A″ photodetachment transition of Fe{sub 5}O{sup −}. We report electron affinities of 1.6980(3) eV for Fe{sub 4}O and 1.8616(3) eV for Fe{sub 5}O, although there is some uncertainty as to whether the {sup 15}A{sub 2} state is the true ground state of Fe{sub 4}O. The iron atoms have a distorted tetrahedral geometry in Fe{sub 4}O{sup 0/−} and a distorted trigonal-bipyramidal arrangement in Fe{sub 5}O{sup 0/−}. For both neutral and anionic species, the oxygen atom preferably binds in a μ{sub 2}-oxo configuration along the cluster edge. This finding is in contrast to prior predictionsmore » that Fe{sub 5}O{sup 0/−} exhibits a μ{sub 3} face-bound structure.« less

Authors:
;  [1];  [1];  [2]
  1. Department of Chemistry, University of California, Berkeley, California 94720 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22678970
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 145; Journal Issue: 5; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; DENSITY FUNCTIONAL METHOD; EXCITED STATES; EXPERIMENTAL DATA; GROUND STATES; IRON IONS; IRON OXIDES; PHOTOELECTRON SPECTROSCOPY; SPECTRA

Citation Formats

Weichman, Marissa L., DeVine, Jessalyn A., Neumark, Daniel M., E-mail: dneumark@berkeley.edu, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720. High-resolution photoelectron imaging spectroscopy of cryogenically cooled Fe{sub 4}O{sup −} and Fe{sub 5}O{sup −}. United States: N. p., 2016. Web. doi:10.1063/1.4960176.
Weichman, Marissa L., DeVine, Jessalyn A., Neumark, Daniel M., E-mail: dneumark@berkeley.edu, & Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720. High-resolution photoelectron imaging spectroscopy of cryogenically cooled Fe{sub 4}O{sup −} and Fe{sub 5}O{sup −}. United States. doi:10.1063/1.4960176.
Weichman, Marissa L., DeVine, Jessalyn A., Neumark, Daniel M., E-mail: dneumark@berkeley.edu, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720. Sun . "High-resolution photoelectron imaging spectroscopy of cryogenically cooled Fe{sub 4}O{sup −} and Fe{sub 5}O{sup −}". United States. doi:10.1063/1.4960176.
@article{osti_22678970,
title = {High-resolution photoelectron imaging spectroscopy of cryogenically cooled Fe{sub 4}O{sup −} and Fe{sub 5}O{sup −}},
author = {Weichman, Marissa L. and DeVine, Jessalyn A. and Neumark, Daniel M., E-mail: dneumark@berkeley.edu and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720},
abstractNote = {We report high-resolution photodetachment spectra of the cryogenically cooled iron monoxide clusters Fe{sub 4}O{sup −} and Fe{sub 5}O{sup −} obtained with slow photoelectron velocity-map imaging (cryo-SEVI). Well-resolved vibrational progressions are observed in both sets of spectra, and transitions to low-lying excited states of both species are seen. In order to identify the structural isomers, electronic states, and vibrational modes that contribute to the cryo-SEVI spectra of these clusters, experimental results are compared with density functional theory calculations and Franck-Condon simulations. The main bands observed in the SEVI spectra are assigned to the {sup 15}A{sub 2}←{sup 16}B{sub 2} photodetachment transition of Fe{sub 4}O{sup −} and the {sup 17}A′←{sup 18}A″ photodetachment transition of Fe{sub 5}O{sup −}. We report electron affinities of 1.6980(3) eV for Fe{sub 4}O and 1.8616(3) eV for Fe{sub 5}O, although there is some uncertainty as to whether the {sup 15}A{sub 2} state is the true ground state of Fe{sub 4}O. The iron atoms have a distorted tetrahedral geometry in Fe{sub 4}O{sup 0/−} and a distorted trigonal-bipyramidal arrangement in Fe{sub 5}O{sup 0/−}. For both neutral and anionic species, the oxygen atom preferably binds in a μ{sub 2}-oxo configuration along the cluster edge. This finding is in contrast to prior predictions that Fe{sub 5}O{sup 0/−} exhibits a μ{sub 3} face-bound structure.},
doi = {10.1063/1.4960176},
journal = {Journal of Chemical Physics},
number = 5,
volume = 145,
place = {United States},
year = {Sun Aug 07 00:00:00 EDT 2016},
month = {Sun Aug 07 00:00:00 EDT 2016}
}