Single electron capture by doubly-charged toluene cations upon collision with various target gases has been investigated by sector tandem mass spectrometry. Both non-dissociative and dissociative charge transfer reactions leading to C7H7+ + H and to C5H5+ + [C2,H3] are detected. Seven atomic or molecular target gases have been used with ionisation energies ranging from 8.8 eV to 14 eV. The branching ratios between the different non-dissociative and dissociative exit channels have been determined as well as the translational energy release on the dissociation products. The experimental data are compared to the predictions of a two-state semi-classical theoretical model that takes into account the non-adiabatic transition responsible for the charge transfer reaction. A wide reaction window shows up but the internal energies of the C7H8+ cations produced by single electron capture are observed to be larger than expected. We assign this effect partly to the influence of the large density of vibrational states and to the multichannel nature of the process. Excited states of the dication are also most probably involved in the charge exchange reaction.
MayV.KühnO., Charge and Energy Transfer Dynamics in Molecular Systems.Wiley-VCH, Berlin (2000).
2.
VekeyK., “Multiply Charged Ions”, Mass Spectrom. Rev.14, 195–225 (1995).
3.
ColeR.B., “Some Tenets Pertaining to Electrospray Ionization Mass Spectrometry”, J. Mass Spectrom.35, 763–772 (2000).
4.
de HoffmannE.StroobantV., Mass Spectrometry: Principles and Applications, 2nd Edn.John Wiley & Sons, Chichester (2001).
5.
HermanZ., “Dynamics of Charge Transfer and Chemical Reactions of Doubly-Charged Ions at Low-Collision Energies”, Int. Rev. Phys. Chem.15, 299–324 (1996).
6.
OlsonR.E., “Charge Transfer at Large Internuclear Distances: Application to Asymmetric Alkali-Ion-Alkali-Atom Systems”, Phys. Rev. A6, 1822–1830 (1972).
7.
OlsonR.E.KimuraM., “Angular Scattering in Slow Multiply-Charged Ion, Atom Collisions”, J. Phys. B15, 4321–4328 (1982).
8.
SuzukiR.NakamuraH.IshiguroE., “Semiclassical Scattering Theory Based on the Dynamical-State Representation: Application to the Li+ + Na and Li + Na+ Collisions”, Phys. Rev. A29, 3060–3070 (1984).
9.
FriedrichB.PickŠ.HládekL.HermanZ.NikitinE.E.ReznikovA.I.UmanskiiS. Y., “Dynamics of Charge Transfer Ar2+ (3P) + He (1S) → Ar+ (2P) + He+ (2S) at Low Collision Energies: Comparison of Experimental Results with Quasiclassical Calculations of the Differential Cross Sections”, J. Chem. Phys.84, 807–812 (1986).
10.
HermanZ.JonathanP.BrentonA.G.BeynonJ.H., “Non Dissociative Single-Electron Capture by CO2+ from Rare Gases”, Chem. Phys. Lett.141, 433–442 (1987).
11.
RogersS.A.PriceS.D.LeoneS.R., “Charge Transfer and Collision-Induced Dissociation Reactions of CO2+ with the Rare Gases at ELab=49eV”, J. Chem. Phys.98, 280–289 (1993).
12.
PriceS.D.RogersS.A.LeoneS.R., “Charge Transfer and Collision-Induced Dissociation Reactions of OCS2+ and CO22+ with the Rare Gases at a Laboratory Collision Energy of 49 eV”, J. Chem. Phys.98, 9455–9465 (1993).
13.
ManningM.PriceS.D.LeoneS.R., “Charge Transfer and Collision-Induced Dissociation Reactions of CF2+ and CF22+”, J. Chem. Phys.99, 8695–8704 (1993).
14.
FárníkM.HermanZ.RuhaltingerT.ToenniesJ.P., “Single-Electron Transfer in Collisions of He2+ with NH3 and H2S: Vibrational State Populations of NH3+ and H2S+”, J. Chem. Phys.103, 3495–3500 (1995).
15.
LeyhB.HautotD., “Mechanisms of Single-Electron Capture by the Dichlorocarbene Cation”, J. Am. Soc. Mass Spectrom.7, 266–275 (1996).
16.
KusakabeT.HosomiK.NakanishiH.TawaraH.SasaoM.NakaiY.KimuraM., “Charge-Transfer Processes in Collisions of Ground-State C+ Ions with H2, D2, CO and CO2 Molecules in the Energy Range from 0.15 to 4.5 keV”, Phys. Rev. A60, 344–350 (1999).
17.
McCulloughR.W., “Excited State Formation in Studies of Electron Capture by State Prepared Doubly Charged Atomic Ions”, Int. J. Mass Spectrom.192, 141–147 (1999).
18.
von KödingH.NibberingN.M.M., “A Fourier Transform Ion Cyclotron Resonance Study of Two- and One-Electron Capture Reactions between Doubly Charged Rare Gas Ions and Rare Gas Atoms”, Int. J. Mass Spectrom.185/186/187, 281–289 (1999).
19.
HermanZ.ŽabkaJ.DolejšekZ.FárníkM., “Dynamics of Chemical and Charge Transfer Reactions of Molecular Dications: Beam Scattering and Total Cross Section Data on CF2D+ (CF2H+), CF2+ and CF+ formations in CF22+ + D2 (H2) collisions”, Int. J. Mass Spectrom.192, 191–203 (1999).
20.
VaeckN.Bacchus-MontabonelM.-C.BaloïtchaE.Desouter-LecomteM., “Time-Dependent Wave-Packet Treatment of the Si4+ + He Collision”, Phys. Rev. A63, 042704/1–042704/8 (2001).
21.
VékeyK.BrentonA.G.BeynonJ.H., “Electron Capture-Induced Decomposition (ECID): A New Method to Study Electron-Capture Collisions”, Int. J. Mass Spectrom. Ion Processes70, 277–300 (1986).
22.
HorningS.R.KotiahoT.DejarmeL.E.WoodJ.M.CooksR. G., “Dissociative Charge Transfer of Singly- and Doubly-Charged Rare Gas Ions with W(CO)6”, Int. J. Mass Spectrom. Ion Processes110, 1–29 (1991).
23.
CooksR.G.AstT.KrajlB.KramerV.ŽigonD., “Internal Energy Distributions Deposited in Doubly and Singly Charged Tungsten Hexacarbonyl Ions Generated by Charge Stripping, Electron Impact, and Charge Exchange”, J. Am. Soc. Mass Spectrom.1, 16–27 (1990).
24.
VékeyK.BrentonA.G.BeynonJ.H., “Electron Capture Induced Decomposition of the Benzene C6H62+ Ion”, J. Phys. Chem.90, 3569–3577 (1986).
25.
KingstonR.G.BrentonA.G.BeynonJ.H., “Electron-Capture Reactions of Multiply Charged Polycyclic Aromatic Ions”, Int. J. Mass Spectrom. Ion Processes77, 223–232 (1987).
26.
VékeyK.BrentonA.G.BeynonJ. H., “Electron Capture-Induced Decomposition of the Pyridine [C5H5N]2+ Ion”, Int. J. Mass Spectrom. Ion Processes87, 121–133 (1989).
27.
LeyhB.HoxhaA., “Reaction Window in the Single-Electron-Capture by Ammonia Dications”, Chem. Phys.192, 65–77 (1995).
28.
BombachR.DannacherJ.StadelmannJ.P., “Energy and Time Dependance of the Decay Processes of Toluene Molecular Cations”, J. Am. Chem. Soc.105, 4205–4211 (1983).
29.
LifshitzC., “Tropylium Ion Formation from Toluene: Solution of an Old Problem in Organic Mass Spectrometry”, Acc. Chem. Res.27, 138–144 (1994).
30.
ShawD.A.HollandD.M.P.MacDonaldM.A.HayesM.A.ShpinkovaL.G.RennieE.E.JohnsonC.A.F.ParkerJ.E.von NiessenW., “An Experimental and Theoretical Study of the Spectroscopic and Thermodynamic Properties of Toluene”, Chem. Phys.230, 97–116 (1998).
31.
SchwellM.DulieuF.GéeC.JochimsH.-W.ChotinJ.-L.BaumgärtelH.LeachS., “Photoionization Mass Spectrometry of Six Isomers of C7H8 in the 7–22 photon energy range”, Chem. Phys.260, 261–279 (2000).
32.
FieldT.A.DulieuF.FillionJ.-H.ChotinJ.-L.DouinS.LemaireJ.-L.LeachS., “Fragmentation of Three Isotopic Toluene Monocations in the 15–100 eV Photon Energy Range”, Chem. Phys.250, 81–110 (1999).
33.
HuangF.-S.DunbarR., “Time-Resolved Photodissociation of Toluene Ion”, Int. J. Mass Spectrom. Ion Processes109, 151–170 (1991).
34.
OhmichiN.GotkisI.SteensL.LifshitzC., “Time-Dependent Mass Spectra and Breakdown Graphs: 15-Toluene-d8”, Org. Mass Spectrom.27, 383–389 (1992).
35.
MoonJ.H.ChoeJ.C.KimM.S., “Kinetic Energy Release Distribution in the Dissociation of Toluene Molecular Ion. The Tropylium vs Benzylium Story Continues”, J. Phys. Chem. A104, 458–463 (2000).
36.
BoydR.K.BeynonJ.H., “Scanning of Sector Mass Spectrometers to Observe the Fragmentation of Metastable Ions”, Org. Mass Spectrom.12, 163–165 (1977).
37.
BarberM.GreenB.N.WolstenholmeW.A.JenningsK.R., “Fragmentation Maps and Their Use in Structural Analysis”, Adv. Mass Spectrom.4, 89–98 (1968).
38.
HolmesJ.L., “Assigning Structures to Ions in the Gas Phase”, Org. Mass Spectrom.20, 169–183 (1985).
39.
BeynonJ.H.FontaineA.E.LesterG.R., “Decomposition of Metastable Ions Involving the Release of Internal Energy. Shapes of Ion Kinetic Energy Peaks”, Int. J. Mass Spectrom. Ion Phys.8, 341–363 (1972).
40.
HolmesJ.L.OsborneA.D., “Metastable Ion Studies. (VIII): An Analytical Method for Deriving Kinetic Energy Release Distributions from Metastable Peaks”, Int. J. Mass Spectrom. Ion Phys.23, 189–200 (1977).
41.
CooksR.G.BeynonJ.H.CaprioliR.M.LesterG.R., Metastable Ions.Elsevier, New York (1973).
42.
NakamuraH., “Semi-Classical Approach to Charge-Transfer Processes in Ion-Molecule Collisions”, Adv. Chem. Phys.82, 243–319 (1992).
43.
NakamuraH., Nonadiabatic Transitions. Concepts, Basic Theories and Applications.World Scientific, New Jersey (2002).
44.
LorquetJ.C.LeyhB., “Nonadiabatic reactions”, in Encyclopedia of Mass Spectrometry, Ed by GrossM.L.CaprioliR., Elsevier, New York (2003).
45.
BoydR.K.KingstonE.E.BrentonA.G.BeynonJ.H., “Angle-Dependence of Ion Kinetic Energy Spectra Obtained by Using Mass Spectrometers. I. Theoretical Consequences of Conservation Laws for Collisions”, Proc. Roy. Soc. Lond. A392, 59–88 (1984).
46.
LandauL., “Theory of Energy Transfer”, Physik. Z. Sowjetunion2, 46–51 (1932).
47.
ZenerC., “Non-Adiabatic Crossing of Energy Levels”, Proc. Roy. Soc. London A137, 696–702 (1932).
48.
StueckelbergE.C.G., “Theory of Inelastic Collisions between Atoms”, Helv. Phys. Acta5, 369–422 (1933).
49.
DemkovY.N., “Charge Exchange with Small Energy Transfer”Proc. Int. Conf. Phys. Electron At. Collisions1963, 831–838 (1964).
50.
OlsonR.E.SmithF.T.BauerE., “Estimation of the Coupling Matrix Elements for One-Electron Transfer Systems”, Appl. Optics10, 1848–1855 (1971).
51.
FatiD.LorquetJ.C.LeyhB., “Maximum Entropy Analysis of the Loss of Hydrogen by Toluene Cations”, in preparation.
52.
Jordan-EngelnG.ReutterF., Numerische Mathematik für Ingenieure.B.-I. Wissenschaftsverlag, Mannheim (1982).
53.
RabalaisJ.W., Principles of Ultraviolet Photoelectron Spectroscopy.John Wiley & Sons, New York (1977).
54.
IllenbergerE.MomignyJ., Gaseous Molecular Ions. An Introduction to Elementary Processes Induced by Ionization.Steinkopff Verlag, Darmstadt (1992).
55.
HickmanC.G.GascookeJ.R.LawranceW.D., “The S1-S0 (1B2-1A1) transition of jet-cooled toluene: Excitation and Dispersed Fluorescence Spectra, Fluorescence Lifetimes, and Intramolecular Vibrational Energy Redistribution”, J. Chem. Phys.104, 4887–4901 (1996).
56.
FatiD.LeyhB., “Charge transfer in molecular systems. Role of the vibrational motion”, to be published.
57.
DormanF.H.MorrisonJ. D., “Double and Triple Ionization in Molecules Induced by Electron Impact”, J. Chem. Phys.35, 575–581 (1961).
58.
LiasS.G.BartmessJ.E.LiebmanJ.F.HolmesJ.L.LevinR.D.MallardW.G., “Gas-Phase Ion and Neutral Thermochemistry”, J. Phys. Chem. Ref. Data17, supplement No. 1 (1988).
59.
GlukhovtsevM.N.BachR.D.LaiterS., “Computational Study of the Thermochemistry of C5H5+ Isomers: Which C5H5+ Isomer Is the Most Stable?”, J. Phys. Chem.100, 10952–10955 (1996).
60.
AstT.BeynonJ.H.CooksR.G., “Charge Localization: Doubly-Charged Ion Reactions in Toluene”, Org. Mass Spectrom.6, 741–747 (1972).
61.
LeeT.G.KimM.S.ParkS.G., “Partitioning of the Nonfixed Excess Energy and the Reverse Critical Energy in CH2OH+ → CHO+ + H2: A Classical Trajectory Study”, J. Chem. Phys.104, 5472–5478 (1996).
62.
ChoiT.H.ParkS.T.KimM.S., “Theoretical and Experimental Studies of the Dissociation Dynamics of Methaniminium Cation, CH2NH2+ → CHNH+ + H2: Reaction Path Bifurcation”, J. Chem. Phys.114, 6051–6057 (2001).
63.
LorquetJ.C.LorquetA.J., “Unimolecular Reaction Dynamics from Kinetic Energy Release Distributions. 8. Protonated Fluorobenzene and Structure of the Phenyl Ion”, J. Phys. Chem. A105, 3719–3724 (2001).
64.
JenningsK.R.FutrellJ.H., “Decomposition of Tropylium and Substituted Tropylium Ions”, J. Chem. Phys.44, 4315–4319 (1966).
65.
LablanquieP.OhashiK.NishiN., “Laser Photodissociation of C7H7+ Created through Multiphoton Ionization of Para-Chlorotoluene”, J. Chem. Phys.98, 399–407 (1993).
