1
|
Le Vot C, Lemaire J, Pernot P, Heninger M, Mestdagh H, Louarn E. Oxygen anion (O - ) and hydroxide anion (HO - ) reactivity with a series of old and new refrigerants. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:336-352. [PMID: 29271073 DOI: 10.1002/jms.4054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 12/08/2017] [Accepted: 12/12/2017] [Indexed: 06/07/2023]
Abstract
The reactivity of a series of commonly used halogenated compounds (trihalomethanes, chlorofluorocarbon, hydrochlorofluorocarbon, fluorocarbons, and hydrofluoroolefin) with hydroxide and oxygen anion is studied in a compact Fourier transform ion cyclotron resonance. O- is formed by dissociative electron attachment to N2 O and HO- by a further ion-molecule reaction with ammonia. Kinetic experiments are performed by increasing duration of introduction of the studied molecule at a constant pressure. Hydroxide anion reactions mainly proceed by proton transfer for all the acidic compounds. However, nucleophilic substitution is observed for chlorinated and brominated compounds. For fluorinated compounds, a specific elimination of a neutral fluorinated alkene is observed in our results in parallel with the proton transfer reaction. Oxygen anion reacts rapidly and extensively with all compounds. Main reaction channels result from nucleophilic substitution, proton transfer, and formal H2+ transfer. We highlight the importance of transfer processes (atom or ion) in the intermediate ion-neutral complex, explaining part of the observed reactivity and formed ions. In this paper, we present the first reactivity study of anions with HFO 1234yf. Finally, the potential of O- and HO- as chemical ionization reagents for trace analysis is discussed.
Collapse
Affiliation(s)
- Clotilde Le Vot
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
| | - Joël Lemaire
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
| | - Pascal Pernot
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
| | - Michel Heninger
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
- AlyXan, Juvisy-sur-Orge, France
| | - Hélène Mestdagh
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
| | - Essyllt Louarn
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
| |
Collapse
|
2
|
|
3
|
Wei PY, Chang YP, Lee YS, Lee WB, Lin KC, Chen KT, Chang AHH. Br2 molecular elimination in 248nm photolysis of CHBr2Cl by using cavity ring-down absorption spectroscopy. J Chem Phys 2007; 126:034311. [PMID: 17249875 DOI: 10.1063/1.2426334] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Elimination of molecular bromine is probed in the B (3)Pi(ou) (+)<--X (1)Sigma(g) (+) transition following photodissociation of CHBr(2)Cl at 248 nm by using cavity ring-down absorption spectroscopy. The quantum yield for the Br(2) elimination reaction is determined to be 0.05+/-0.03. The nascent vibrational population ratio of Br(2)(v=1)Br(2)(v=0) is obtained to be 0.5+/-0.2. A supersonic beam of CHBr(2)Cl is similarly photofragmented and the resulting Br atoms are monitored with a velocity map ion-imaging detection, yielding spatial anisotropy parameters of 1.5 and 1.1 with photolyzing wavelengths of 234 and 267 nm, respectively. The results justify that the excited state promoted by 248 nm should have an A(") symmetry. Nevertheless, when CHBr(2)Cl is prepared in a supersonic molecular beam under a cold temperature, photofragmentation gives no Br(2) detectable in a time-of-flight mass spectrometer. A plausible pathway via internal conversion is proposed with the aid of ab initio potential energy calculations. Temperature dependence measurements lend support to the proposed pathway. The production rates of Br(2) between CHBr(2)Cl and CH(2)Br(2) are also compared to examine the chlorine-substituted effect.
Collapse
Affiliation(s)
- Pei-Ying Wei
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | | | | | | | | | | | | |
Collapse
|
4
|
Peverall R, Kennedy R, Mayhew C, Watts P. Selected ion flow tube study of the reactions of O− and O2− with CHC12F, CHC1F2, CHF3, CH2C1F, CH2F2, CH3F, CHF2CHF2, CH2FCF3, and CH3CHF2. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0168-1176(97)00023-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
5
|
Thomas RD, Kennedy RA, Mayhew CA, Watts P. Reactions of H3O+ and H2O+ with Several Fully Halogenated Bromomethanes. J Phys Chem A 1997. [DOI: 10.1021/jp9719624] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R. D. Thomas
- Chemical Physics Laboratory, School of Physics and Space Research, University of Birmingham, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., and PLSD, CBD, Porton Down, Salisbury, Wiltshire SP4 0JQ, U.K
| | - R. A. Kennedy
- Chemical Physics Laboratory, School of Physics and Space Research, University of Birmingham, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., and PLSD, CBD, Porton Down, Salisbury, Wiltshire SP4 0JQ, U.K
| | - C. A. Mayhew
- Chemical Physics Laboratory, School of Physics and Space Research, University of Birmingham, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., and PLSD, CBD, Porton Down, Salisbury, Wiltshire SP4 0JQ, U.K
| | - P. Watts
- Chemical Physics Laboratory, School of Physics and Space Research, University of Birmingham, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K., and PLSD, CBD, Porton Down, Salisbury, Wiltshire SP4 0JQ, U.K
| |
Collapse
|