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Title: The nature of the CO2- radical anion in water

Abstract

The reductive conversion of CO2 into industrial products (e.g., oxalic acid, formic acid, methanol) can occur via aqueous CO2- as a transient intermediate. While the formation, structure, and reaction pathways of this radical anion have been modelled for decades using various spectroscopic and theoretical approaches, here, for the first time, we present a vibrational spectroscopic investigation in liquid water, using pulse radiolysis time-resolved resonance Raman spectroscopy for its preparation and observation. Excitation of the radical in resonance with its 235 nm absorption displays a transient Raman band at 1298 cm-1, attributed to the symmetric CO stretch, which is at ~45 cm-1 higher frequency than in inert matrices. Isotopic substitution at C (13CO2-) shifts the frequency downwards by 22 cm-1, which confirms its origin and the assignment. A Raman band of moderate intensity compared to the stronger 1298 cm-1 band also appears at 742 cm-1 and is assignable to the OCO bending mode. A reasonable resonance enhancement of this mode is possible only in a bent CO2-(C2v/Cs) geometry. These resonance Raman features suggest a strong solute-solvent interaction, the water molecules acting as constituents of the radical structure, rather than exerting a minor solvent perturbation. However, there is no evidence of themore » non-equivalence (Cs) of the two CO bonds. A surprising resonance Raman feature is the lack of overtones of the symmetric CO stretch, which we interpret due to the detachment of the electron from the CO2- moiety towards the solvation shell. Electron detachment occurs at the energies of 0.28 ± 0.03 eV or higher with respect to the zero point energy of the ground electronic state. The issue of acid-base equilibrium of the radical, which has been in contention for decades, as reflected in a wide variation in the reported pKa (-0.2 to 3.9), has been resolved. A value of 3.4 ± 0.2 measured in this work is consistent with the vibrational properties, bond structure, and charge distribution in aqueous CO2-.« less

Authors:
ORCiD logo [1];  [1]
  1. Univ. of Notre Dame, IN (United States). Radiation Lab.
Publication Date:
Research Org.:
Univ. of Notre Dame, IN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division
OSTI Identifier:
1470757
Alternate Identifier(s):
OSTI ID: 1248059
Grant/Contract Number:  
FC02-04ER15533
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 144; Journal Issue: 15; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY

Citation Formats

Janik, Ireneusz, and Tripathi, G. N. R. The nature of the CO2- radical anion in water. United States: N. p., 2016. Web. doi:10.1063/1.4946868.
Janik, Ireneusz, & Tripathi, G. N. R. The nature of the CO2- radical anion in water. United States. https://doi.org/10.1063/1.4946868
Janik, Ireneusz, and Tripathi, G. N. R. Tue . "The nature of the CO2- radical anion in water". United States. https://doi.org/10.1063/1.4946868. https://www.osti.gov/servlets/purl/1470757.
@article{osti_1470757,
title = {The nature of the CO2- radical anion in water},
author = {Janik, Ireneusz and Tripathi, G. N. R.},
abstractNote = {The reductive conversion of CO2 into industrial products (e.g., oxalic acid, formic acid, methanol) can occur via aqueous CO2- as a transient intermediate. While the formation, structure, and reaction pathways of this radical anion have been modelled for decades using various spectroscopic and theoretical approaches, here, for the first time, we present a vibrational spectroscopic investigation in liquid water, using pulse radiolysis time-resolved resonance Raman spectroscopy for its preparation and observation. Excitation of the radical in resonance with its 235 nm absorption displays a transient Raman band at 1298 cm-1, attributed to the symmetric CO stretch, which is at ~45 cm-1 higher frequency than in inert matrices. Isotopic substitution at C (13CO2-) shifts the frequency downwards by 22 cm-1, which confirms its origin and the assignment. A Raman band of moderate intensity compared to the stronger 1298 cm-1 band also appears at 742 cm-1 and is assignable to the OCO bending mode. A reasonable resonance enhancement of this mode is possible only in a bent CO2-(C2v/Cs) geometry. These resonance Raman features suggest a strong solute-solvent interaction, the water molecules acting as constituents of the radical structure, rather than exerting a minor solvent perturbation. However, there is no evidence of the non-equivalence (Cs) of the two CO bonds. A surprising resonance Raman feature is the lack of overtones of the symmetric CO stretch, which we interpret due to the detachment of the electron from the CO2- moiety towards the solvation shell. Electron detachment occurs at the energies of 0.28 ± 0.03 eV or higher with respect to the zero point energy of the ground electronic state. The issue of acid-base equilibrium of the radical, which has been in contention for decades, as reflected in a wide variation in the reported pKa (-0.2 to 3.9), has been resolved. A value of 3.4 ± 0.2 measured in this work is consistent with the vibrational properties, bond structure, and charge distribution in aqueous CO2-.},
doi = {10.1063/1.4946868},
journal = {Journal of Chemical Physics},
number = 15,
volume = 144,
place = {United States},
year = {Tue Apr 19 00:00:00 EDT 2016},
month = {Tue Apr 19 00:00:00 EDT 2016}
}

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Works referenced in this record:

The vibrational spectra of CO2+, (CO2)2+, CO2−, and (CO2)2− trapped in solid neon
journal, September 1999

  • Thompson, Warren E.; Jacox, Marilyn E.
  • The Journal of Chemical Physics, Vol. 111, Issue 10
  • DOI: 10.1063/1.479212

Photodissociation of CO2− in water clusters via Renner-Teller and conical interactions
journal, April 2007

  • Habteyes, Terefe; Velarde, Luis; Sanov, Andrei
  • The Journal of Chemical Physics, Vol. 126, Issue 15
  • DOI: 10.1063/1.2717932

Ab initio molecular dynamics simulations reveal localization and time evolution dynamics of an excess electron in heterogeneous CO 2 –H 2 O systems
journal, January 2014

  • Liu, Ping; Zhao, Jing; Liu, Jinxiang
  • The Journal of Chemical Physics, Vol. 140, Issue 4
  • DOI: 10.1063/1.4863343

The interaction of negative charge with carbon dioxide – insight into solvation, speciation and reductive activation from cluster studies
journal, September 2014


Collisional ionization of Na, K, and Cs by CO2, COS, and CS2: Molecular electron affinities
journal, January 1975

  • Compton, R. N.; Reinhardt, P. W.; Cooper, C. D.
  • The Journal of Chemical Physics, Vol. 63, Issue 9
  • DOI: 10.1063/1.431875

Electronic absorption spectra of CO 2 - trapped in γ-irradiated crystalline sodium formate
journal, March 1962


Proton Reactivity and Electronic Structure of Phenoxyl Radicals in Water
journal, March 1998

  • Tripathi, G. N. R.
  • The Journal of Physical Chemistry A, Vol. 102, Issue 13
  • DOI: 10.1021/jp9808633

Pulse radiolytic investigation of the carboxyl radical in aqueous solution
journal, August 1970

  • Fojtik, A.; Czapski, Gideon; Henglein, A.
  • The Journal of Physical Chemistry, Vol. 74, Issue 17
  • DOI: 10.1021/j100711a008

Raman Spectra of Polyatomic Gases
journal, August 1929


Reactions of Hydrated Electrons (H2O)n− with Carbon Dioxide and Molecular Oxygen: Hydration of the CO2− and O2− Ions
journal, October 2004

  • Balaj, O. Petru; Siu, Chi-Kit; Balteanu, Iulia
  • Chemistry - A European Journal, Vol. 10, Issue 19
  • DOI: 10.1002/chem.200400416

A Simple ab Initio Model for the Hydrated Electron That Matches Experiment
journal, August 2015

  • Kumar, Anil; Walker, Jonathan A.; Bartels, David M.
  • The Journal of Physical Chemistry A, Vol. 119, Issue 34
  • DOI: 10.1021/acs.jpca.5b04721

Acid dissociation constant of the carboxyl radical. Pulse radiolysis studies of aqueous solutions of formic acid and sodium formate
journal, January 1973

  • Buxton, G. V.; Sellers, R. M.
  • Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, Vol. 69, Issue 0
  • DOI: 10.1039/f19736900555

ESR measurement of the pKa of carboxyl radical and ab initio calculation of the carbon-13 hyperfine constant
journal, February 1990

  • Jeevarajan, A. S.; Carmichael, Ian.; Fessenden, Richard W.
  • The Journal of Physical Chemistry, Vol. 94, Issue 4
  • DOI: 10.1021/j100367a033

The nature of the superoxide radical anion in water
journal, July 2013

  • Janik, Ireneusz; Tripathi, G. N. R.
  • The Journal of Chemical Physics, Vol. 139, Issue 1
  • DOI: 10.1063/1.4811697

Pulse radiolysis of aliphatic acids in aqueous solutions. I. Simple monocarboxylic acids
journal, December 1969

  • Neta, Pedatsur; Simic, Miomir; Hayon, Elie
  • The Journal of Physical Chemistry, Vol. 73, Issue 12
  • DOI: 10.1021/j100846a029

Comment on the structure and stability of (CO 2 ) 2
journal, May 1979

  • Rossi, Angelo R.; Jordan, Kenneth D.
  • The Journal of Chemical Physics, Vol. 70, Issue 9
  • DOI: 10.1063/1.438018

Electron affinities of CO2, OCS, and CS2
journal, April 1998

  • Gutsev, Gennady L.; Bartlett, Rodney J.; Compton, Robert N.
  • The Journal of Chemical Physics, Vol. 108, Issue 16
  • DOI: 10.1063/1.476091

The early events in the OH radical oxidation of dimethyl sulfide in water
journal, January 2013

  • Janik, Ireneusz; Tripathi, G. N. R.
  • The Journal of Chemical Physics, Vol. 138, Issue 4
  • DOI: 10.1063/1.4788664

Electron attachment to van der Waals polymers of carbon dioxide and nitrous oxide
journal, August 1978

  • Klots, Cornelius E.; Compton, R. N.
  • The Journal of Chemical Physics, Vol. 69, Issue 4
  • DOI: 10.1063/1.436738

Stable gas phase hydrates of the CO 2 anion
journal, November 1979

  • Klots, Cornelius E.
  • The Journal of Chemical Physics, Vol. 71, Issue 10
  • DOI: 10.1063/1.438193

Estimation of rate constants for near-diffusion-controlled reactions in water at high temperatures
journal, January 1990

  • Elliot, A. John; McCracken, David R.; Buxton, George V.
  • Journal of the Chemical Society, Faraday Transactions, Vol. 86, Issue 9
  • DOI: 10.1039/ft9908601539

Reactions of hydrated electron clusters (H2O)n-: scavenging the excess electron
journal, February 1989

  • Posey, Lynmarie A.; DeLuca, Michael J.; Campagnola, Paul J.
  • The Journal of Physical Chemistry, Vol. 93, Issue 4
  • DOI: 10.1021/j100341a003

Bottom-Up View of Water Network-Mediated CO 2 Reduction Using Cryogenic Cluster Ion Spectroscopy and Direct Dynamics Simulations
journal, December 2011

  • Breen, Kristin J.; DeBlase, Andrew F.; Guasco, Timothy L.
  • The Journal of Physical Chemistry A, Vol. 116, Issue 3
  • DOI: 10.1021/jp209493v

Thermal Energy Reactions of Size-Selected Hydrated Electron Clusters (H 2 O) n -
journal, January 1996

  • Arnold, Susan T.; Morris, Robert A.; Viggiano, A. A.
  • The Journal of Physical Chemistry, Vol. 100, Issue 8
  • DOI: 10.1021/jp952584a

Pulse radiolysis of sodium formate aqueous solution up to 400°C: Absorption spectra, kinetics and yield of carboxyl radical CO2−
journal, October 2008


Electron attachment to carbon dioxide clusters in a supersonic beam
journal, August 1977

  • Klots, Cornelius E.; Compton, R. N.
  • The Journal of Chemical Physics, Vol. 67, Issue 4
  • DOI: 10.1063/1.435044

Critical Review of rate constants for reactions of hydrated electrons, hydrogen atoms and hydroxyl radicals (⋅OH/⋅O in Aqueous Solution
journal, April 1988

  • Buxton, George V.; Greenstock, Clive L.; Helman, W. Phillips
  • Journal of Physical and Chemical Reference Data, Vol. 17, Issue 2
  • DOI: 10.1063/1.555805

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Infrared Spectroscopy of Size‐Selected Hydrated Carbon Dioxide Radical Anions CO 2 .− (H 2 O) n ( n =2–61) in the C−O Stretch Region
journal, June 2019

  • Herburger, Andreas; Ončák, Milan; Siu, Chi‐Kit
  • Chemistry – A European Journal, Vol. 25, Issue 43
  • DOI: 10.1002/chem.201901650

Infrared Multiple Photon Dissociation Spectroscopy of Hydrated Cobalt Anions Doped with Carbon Dioxide CoCO 2 (H 2 O) n , n =1–10, in the C−O Stretch Region
journal, January 2020

  • Barwa, Erik; Ončák, Milan; Pascher, Tobias F.
  • Chemistry – A European Journal, Vol. 26, Issue 5
  • DOI: 10.1002/chem.201904182

Photocatalytic Reverse Semi‐Combustion Driven by Ionic Liquids
journal, February 2019

  • Qadir, Muhammad I.; Zanatta, Marcileia; Gil, Eduarda S.
  • ChemSusChem, Vol. 12, Issue 5
  • DOI: 10.1002/cssc.201802974

Single- and double-electron reductions of CO 2 by using superalkalis: An ab initio study
journal, February 2018

  • Srivastava, Ambrish Kumar
  • International Journal of Quantum Chemistry, Vol. 118, Issue 14
  • DOI: 10.1002/qua.25598

Photochemistry of glyoxylate embedded in sodium chloride clusters, a laboratory model for tropospheric sea-salt aerosols
journal, January 2018

  • Bersenkowitsch, Nina K.; Ončák, Milan; van der Linde, Christian
  • Physical Chemistry Chemical Physics, Vol. 20, Issue 12
  • DOI: 10.1039/c8cp00399h

Radiolytic formation of the carbon dioxide radical anion in acetonitrile revealed by transient IR spectroscopy
journal, January 2018

  • Grills, David C.; Lymar, Sergei V.
  • Physical Chemistry Chemical Physics, Vol. 20, Issue 15
  • DOI: 10.1039/c8cp00977e

The selenocyanate dimer radical anion in water: Transient Raman spectra, structure, and reaction dynamics
journal, March 2019

  • Janik, Ireneusz; Tripathi, G. N. R.
  • The Journal of Chemical Physics, Vol. 150, Issue 9
  • DOI: 10.1063/1.5086400

On the origin of the elusive first intermediate of CO 2 electroreduction
journal, September 2018

  • Chernyshova, Irina V.; Somasundaran, Ponisseril; Ponnurangam, Sathish
  • Proceedings of the National Academy of Sciences, Vol. 115, Issue 40
  • DOI: 10.1073/pnas.1802256115