Skip to main content
SpringerLink
Log in

Fragmentation of Organic Ions and Interpretation of EI Mass Spectra

  • Chapter
Mass Spectrometry

Abstract

The following chapter introduces one of the key disciplines of organic mass spectrometry: the common fragmentation pathways of organic ions and the resulting methodology for the interpretation of electron ionization (EI) mass spectra. Of course, a single chapter cannot be comprehensive and thus, further reading may be desirable. [1–6] Applications of mass spectrometry to organic stereochemistry are treated in a monograph, [7] and in addition, there is a vast number of original publications dealing with classes of compounds or fragmentation pathways: these should be consulted to solve a particular problem. This chapter is an attempt to present a systematic introduction to the topic rather by emphasizing the most important fragmentation pathways than by dwelling on countless compounds. It is an attempt to teach the basic skills and to provide a guideline for further “learning by doing”. Throughout the chapter we will keep an eye on the relationship between fragmentation patterns and gas phase ion chemistry. In order to successfully work through these pages, some knowledge of the general concept of mass spectrometry (Chap. 1) and of the basics of electron ionization (Chap. 5) are prerequisite. In addition, you should be familiar with the fundamentals of gas phase ion chemistry (Chap. 2) as well as with isotopic mass and isotopic distributions (Chap. 3).

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Log in via an institution
Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 74.99
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Reference List

  1. Biemann, K.; Dibeler, V.H.; Grubb, H.M.; Harrison, A.G.; Hood, A.; Knewstubb, P.F.; Krauss, M.; McLafferty, F.W.; Melton, C.E.; Meyerson, S.; Reed, R.I.; Rosenstock, H.M.; Ryhage, R.; Saunders, R.A.; Stenhagen, E.; Williams, A.E. Mass Spectrometry of Organic Ions; 1st ed.; McLafferty, F.W., editor; Academic Press: London, 1963.

    Google Scholar 

  2. Budzikiewicz, H.; Djerassi, C.; Williams, D.H. Mass Spectrometry of Organic Compounds; 1st ed.; Holden-Day: San Francisco, 1967.

    Google Scholar 

  3. Smith, R.M.; Busch, K.L. Understanding Mass Spectra — A Basic Approach; 1st ed.; John Wiley & Sons: New York, 1999.

    Google Scholar 

  4. Budzikiewicz, H. Massenspektrometrie -eine Einführung; 4th ed.; Wiley-VCH: Weinheim, 1998.

    Google Scholar 

  5. McLafferty, F.W.; Turecek, F. Interpretation of Mass Spectra; 4th ed.; University Science Books: Mill Valley, 1993.

    Google Scholar 

  6. Hesse, M.; Meier, H.; Zeeh, B. Massenspektren, in Spektroskopische Methoden in der Organischen Chemie, 6th ed.; Georg Thieme Verlag: Stuttgart, 2002; Chapter 4, pp. 243.

    Google Scholar 

  7. Applications of Mass Spectrometry to Organic Stereochemistry; 1st ed.; Splitter, J.S.; Turecek, F., editors; Verlag Chemie: Weinheim, 1994.

    Google Scholar 

  8. Price, P. Standard Definitions of Terms Relating to Mass Spectrometry. A Report From the Committee on Measurements and Standards of the Amercian Society for Mass Spectrometry. J. Am. Chem. Soc. Mass Spectrom. 1991, 2, 336–348.

    Article  CAS  Google Scholar 

  9. Todd, J.F.J. Recommendations for Nomenclature and Symbolism for Mass Spectroscopy Including an Appendix of Terms Used in Vacuum Technology. Int. J. Mass Spectrom. Ion Proc. 1995, 142, 211–240.

    Article  CAS  Google Scholar 

  10. Svec, H.J.; Junk, G.A. Electron-Impact Studies of Substituted Alkanes. J. Am. Chem. Soc. 1967, 89, 790–796.

    Article  CAS  Google Scholar 

  11. Friedman, L.; Long, F.A. Mass Spectra of Six Lactones. J. Am. Chem. Soc. 1953, 75, 2832–1836.

    Article  CAS  Google Scholar 

  12. Kami, M.; Mandelbaum, A. The ‘Even-Electron Rule’. Org. Mass Spectrom. 1980, 15, 53–64.

    Article  Google Scholar 

  13. Bowen, R.D.; Harrison, A.G. Loss of Methyl Radical From Some Small Iramonium Ions: Unusual Violation of the Even-Electron Rule. Org. Mass Spectrom. 1981, 16, 180–182.

    Article  CAS  Google Scholar 

  14. Krauss, D.; Mainx, H.G.; Tauscher, B.; Bischof, P. Fragmentation of Trimethyl-silyl Derivatives of 2-Alkoxyphenols: a Further Violation of the ‘Even-Electron Rule’. Org. Mass Spectrom. 1985, 20, 614–618.

    Article  CAS  Google Scholar 

  15. Nizigiyimana, L.; Rajan, P.K.; Haemers, A.; Claeys, M.; Derrick, P.J. Mechanistic Aspects of High-Energy Collision-Induced Dissociation Proximate to the Charge in Saturated Fatty Acid n-Butyl Esters Ca-tionized With Lithium. Evidence for Hydrogen Radical Removal. Rapid Commun. Mass Spectrom. 1997, 11, 1808–1812.

    CAS  Google Scholar 

  16. Veith, H.J.; Gross, J.H. Alkane Loss From Collisionally Activated Alkylmethyle-neimmonium Ions. Org. Mass Spectrom. 1991, 26, 1061–1064.

    Article  CAS  Google Scholar 

  17. McLafferty, F.W. Mass Spectrometric Analysis. I. Aliphatic Halogenated Compounds. Anal. Chem. 1962, 34, 2–15.

    Article  CAS  Google Scholar 

  18. Stevenson, D.P. Ionization and Dissociation by Electronic Impact. Ionization Potentials and Energies of Formation of Sec-Propyl and Tert-Butyl Radicals. Some Limitations on the Method. Discuss. Faraday Soc. 1951, 10, 35–45.

    Article  Google Scholar 

  19. Audier, H.E. Ionisation et fragmentation en spectrometrie de masse I. sur la répartition de la charge positive entre fragment provenant des mêmes ruptures. Org. Mass Spectrom. 1969, 2, 283–298.

    Article  CAS  Google Scholar 

  20. Harrison, A.G.; Finney, C.D.; Sherk, J.A. Factors Determining Relative Ionic Abundances in Competing Fragmentation Reactions. Org. Mass Spectrom. 1971, 5, 1313–1320.

    Article  CAS  Google Scholar 

  21. Levsen, K. Reaction Mechanisms, in Fundamental Aspects of Organic Mass Spectrometry, 1st ed.; Verlag Chemie: Weinheim, 1978; pp.152–208.

    Google Scholar 

  22. MST MST Chemistry Webbook. http://webbook.nist.gov 2002.

  23. Sharkey, A.G., Jr.; Shultz, J.L.; Friedel, R.A. Mass Spectra of Ketones. Anal. Chem. 1956, 28, 934–940.

    Article  CAS  Google Scholar 

  24. Gilpin, J.A.; McLafferty, F.W. Mass Spectrometric Analysis: Aliphatic Aldehydes. Anal. Chem. 1957, 29, 990–994.

    Article  CAS  Google Scholar 

  25. Liedtke, R.J.; Djerassi, C. Mass Spectrometry in Structural and Stereochemical Problems. CLXXXIII. A Study of the Electron Impact Induced Fragmentation of Aliphatic Aldehydes. J. Am. Chem. Soc. 1969, 91, 6814–6821.

    Article  CAS  Google Scholar 

  26. Harrison, A.G. The High-Resolution Mass Spectra of Aliphatic Aldehydes. Org. Mass Spectrom. 1970, 3, 549–555.

    Article  CAS  Google Scholar 

  27. Levsen, K.; McLafferty, F.W. Metastable Ion Characteristics. XXVII. Structure and Unimolecular Reactions of [C2H6N]+ and [C3H8N]+ Ions. J. Am. Chem. Soc. 1974, 96, 139–144.

    Article  CAS  Google Scholar 

  28. Bowen, R.D. The Chemistry of [CnH2n+2N]+ Ions. Mass Spectrom. Rev. 1991, 10, 225–279.

    Article  CAS  Google Scholar 

  29. Bowen, R.D. Ion-Neutral Complexes. Accounts of Chemical Research 1991, 24, 364–371.

    Article  CAS  Google Scholar 

  30. Djerassi, C.; Fenselau, C. Mass Spectrometry in Structural and Stereochemical Problems. LXXXIV. The Nature of the Cyclic Transition State in Hydrogen Rearrangements of Aliphatic Ethers. J. Am. Chem. Soc. 1965, 87, 5747–5562.

    Article  CAS  Google Scholar 

  31. McLafferty, F.W. Mass Spectrometric Analysis of Aliphatic Ethers. Anal. Chem. 1957, 29, 1782–1789.

    Article  CAS  Google Scholar 

  32. Friedel, R.A.; Shultz, J.L.; Sharkey, A.G., Jr. Mass Spectra of Alcohols. Anal. Chem. 1956, 28, 927–934.

    Google Scholar 

  33. Gohlke, R.S.; McLafferty, F.W. Mass Spectrometric Analysis of Aliphatic Amines. Anal. Chem. 1962, 34, 1281–1287.

    Article  CAS  Google Scholar 

  34. O’Nier, M.J., Jr.; Wier, T.P., Jr. Mass Spectrometry of Heavy Hydrocarbons. Anal. Chem. 1951, 830–843.

    Google Scholar 

  35. Audier, H.E.; Mühet, A.; Sozzi, G.; Denhez, J.P. The Isomerization Mechanisms of Alky lamines: Structure of [C2H6N]+ and [C3H8N]+ Fragment Ions. Org. Mass Spectrom. 1984, 19, 79–81.

    Article  CAS  Google Scholar 

  36. Phillips, G.R.; Russell, M.E.; Solka, B.H. Structure of the [C2H5O]+ Ion in the Mass Spectrum of Diethyl Ether. Org. Mass Spectrom. 1975, 10, 819–823.

    Article  CAS  Google Scholar 

  37. McAdoo, D.J.; Hudson, C.E. Gas Phase Ionic Reactions Are Generally Stepwise Processes. Int. J. Mass Spectrom. Ion Proc. 1984, 62, 269–276.

    Article  CAS  Google Scholar 

  38. Williams, D.H.; Budzikiewicz, H.; Pelah, Z.; Djerassi, C. Mass Spectroscopy and Its Application to Structural and Stereochemical Problems. XLIV. Fragmentation Behavior of Monocyclic Ketones. Monatsh. Chem. 1964, 95, 166–177.

    Article  CAS  Google Scholar 

  39. Scibl, J.; Gäumann, T. Massenspektren Organischer Verbindungen. 2. Mitteilung: Cyclohexanone. Helv. Chim. Acta 1963, 46, 2857–2872.

    Article  Google Scholar 

  40. Yates, B.F.; Bouma, W.J.; Radom, L. Detection of the Prototype Phosphonium (CH2PH3), Sulfonium (CH2SH2), and Chloronium (CH2C1H) Ylides by Neutralization-Reionization Mass Spectrometry: a Theoretical Prediction. J. Am. Chem. Soc. 1984, 106, 5805–5808.

    Article  CAS  Google Scholar 

  41. Grützmacher, H.-F. Unimolecular Reaction Mechanisms: the Role of Reactive Intermediates. Int. J. Mass Spectrom. Ion Proc. 1992, 118/119, 825–855.

    Article  Google Scholar 

  42. Hammerum, S. Distonic Radical Cations in the Gaseous and Condensed Phase. Mass Spectrom. Rev. 1988, 7, 123–202.

    Article  CAS  Google Scholar 

  43. Stirk, K.M.; Kiminkinen, M.L.K.; Kenttämaa, H.I. Ion-Molecule Reactions of Distonic Radical Cations. Chem. Rev. 1992, 92, 1649–1665.

    Article  CAS  Google Scholar 

  44. Yates, B.F.; Bouma, W.J.; Radom, L. Distonic Radical Cations. Guidelines for the Assessment of Their Stability. Tetrahedron 1986, 42, 6225–6234.

    Article  CAS  Google Scholar 

  45. Hammerum, S.; Derrick, P.J. Thermodynamics of Intermediate Ion-Molecule Complexes or Kinetics of Competing Reactions? The Reactions of Low-Energy Isobutylamine and Neopentylamine Molecular Ions. J. Chem. Soc.,Perkin Trans. 2 1986, 1577–1580.

    Google Scholar 

  46. Yates, B.F.; Radom, L. Intramolecular Hydrogen Migration in Ionized Amines: a Theoretical Study of the Gas-Phase Analogues of the Hofmann-Löffler and Related Rearrangements. J. Am. Chem. Soc. 1987, 109, 2910–2915.

    Article  CAS  Google Scholar 

  47. Zeller, L.; Farrell, J., Jr.; Vainiotalo, P.; Kenttämaa, H.I. Long-Lived Radical Cations of Simple Organophosphates Isomerize Spontaneously to Distonic Structures in the Gas Phase. J. Am. Chem. Soc. 1992, 114, 1205–1214.

    Article  CAS  Google Scholar 

  48. Sack, T.M.; Miller, D.L.; Gross, M.L. The Ring Opening of Gas-Phase Cyclopropane Radical Cations. J. Am. Chem. Soc. 1985, 107, 6795–6800.

    Article  CAS  Google Scholar 

  49. Grubb, H.M.; Meyerson, S. Mass Spectra of Alkylbenzenes, in Mass spectrometry of organic ions, 1st ed.; McLafferty, F.W., editor; Academic Press: New York, 1963; pp. 453–527.

    Chapter  Google Scholar 

  50. McLafferty, F.W.; Bockhoff, F.M. Collisional Activation and Metastable Ion Characteristics. 67. Formation and Stability of Gaseous Tolyl Ions. Org. Mass Spectrom. 1979, 14, 181–184.

    Article  CAS  Google Scholar 

  51. Cone, C.; Dewar, M.J.S.; Landman, D. Gaseous Ions. 1. MINDO/3 Study of the Rearrangement of Benzyl Cation to Tro-pylium. J. Am. Chem. Soc. 1977, 99, 372–376.

    Article  CAS  Google Scholar 

  52. Traeger, J.C.; McLoughlin, R.G. Threshold Photoionization and Dissociation of Toluene and Cycloheptatriene. J. Am. Chem. Soc. 1917 , 99, 7351–7352.

    Article  Google Scholar 

  53. Howe, I.; McLafferty, F.W. Unimolecular Decomposition of Toluene and Cycloheptatriene Molecular Ions. Variation of the Degree of Scrambling and Isotope Effect With Internal Energy. J. Am. Chem. Soc. 1971, 93, 99–105.

    Article  Google Scholar 

  54. Kuck, D. Half a Century of Scrambling in Organic Ions: Complete, Incomplete, Progressive and Composite Atom Interchange. Int. J. Mass Spectrom. 2002, 213, 101–144.

    Article  CAS  Google Scholar 

  55. Griitzmacher, H.-F. Intra- and Intermolecular Reactions of Aromatic Radical Cations: an Account of Mechanistic Concepts and Methods in Mass Spectrometry. Org. Mass Spectrom. 1993, 28, 1375–1387.

    Article  Google Scholar 

  56. Mormann, M.; Kuck, D. Protonated 1,3,5-Cycloheptatriene and 7-Alkyl-1,3,5-Cycloheptatrienes in the Gas Phase: Ring Contraction to the Isomeric Alkylben-zenium Ions. J. Mass Spectrom. 1999, 34, 384–394.

    Article  CAS  Google Scholar 

  57. Rylander, P.N.; Meyerson, S.; Grubb, H.M. Organic Ions in the Gas Phase. II. The Tropylium Ion. J. Am. Chem. Soc. 1957, 79. 842–846.

    Article  CAS  Google Scholar 

  58. Cooks, R.G.; Howe, I.; Tarn, S.W.; Williams, D.H. Studies in Mass Spectrometry. XXIX. Hydrogen Scrambling in Some Bicyclic Aromatic Systems. Randomization Over Two Rings. J. Am. Chem. Soc. 1968, 90, 4064–4069.

    Article  CAS  Google Scholar 

  59. Borchers, F.; Levsen, K. Isomerization of Hydrocarbon Ions. III. [C8H8]+, [C8H8]2+, [C6H6]+, and [C6H5]+ Ions. Org. Mass Spectrom. 1975, 10, 584–594.

    Article  CAS  Google Scholar 

  60. Nishishita, T.; McLafferty, F.W. Metastable Ion Characteristics. XXXXVII. Collisional Activation Mass Spectra of Pentene and Hexene Molecular Ions. Org. Mass Spectrom. 1977, 12, 75–77.

    Article  CAS  Google Scholar 

  61. Levsen, K. Isomerization of Hydrocarbon Ions. II. Octenes and Isomeric Cycloal-kanes. Collisional Activation Study. Org. Mass Spectrom. 1975, 10, 55–63.

    Article  CAS  Google Scholar 

  62. Levsen, K.; Heimbrecht, J. Isomerization of Hydrocarbon Ions. VI. Parameters Determining the Isomerization of Aliphatic Hydrocarbon Ions. Org. Mass Spectrom. 1977, 12, 131–135.

    Article  CAS  Google Scholar 

  63. Borchers, F.; Levsen, K.; Schwarz, H.; Wesdemiotis, C.; Winkler, H.U. Isomerization of Linear Octene Cations in the Gas Phase. J. Am. Chem. Soc. 1977, 99, 6359–6365.

    Article  CAS  Google Scholar 

  64. Schneider, B.; Budzikiewicz, H. A Facile Method for the Localization of a Double Bond in Aliphatic Compounds. Rapid Commun. Mass Spectrom. 1990, 4, 550–551.

    Article  CAS  Google Scholar 

  65. Peake, D.A.; Gross, M.L. Iron(I) Chemical Ionization and Tandem Mass Spectrometry for Locating Double Bonds. Anal. Chem. 1985, 57, 115–120.

    Article  CAS  Google Scholar 

  66. Fordham, P.J.; Chamot-Rooke, J.; Guidice, E.; Tortajada, J.; Morizur, J.-P. Analysis of Alkenes by Copper Ion Chemical Ionization Gas Chromatography/Mass Spectrometry and Gas Chromatography/Tandem Mass Spectrometry. J. Mass Spectrom. 1999, 34, 1007–1017.

    Article  CAS  Google Scholar 

  67. Levsen, K.; Weber, R.; Borchers, F.; Heimbach, H.; Beckey, H.D. Determination of Double Bonds in Alkenes by Field Ionization Mass Spectrometry. Anal. Chem. 1978, 50, 1655–1658.

    Article  CAS  Google Scholar 

  68. Buser, H.-R.; Arn, H.; Guerin, P.; Rauscher, S. Determination of Double Bond Position in Mono-Unsaturated Acetates by Mass Spectrometry of Dimethyl Disulfide Adducts. Anal. Chem. 1983, 55, 818–822.

    Article  CAS  Google Scholar 

  69. Scribe, P.; Guezennec, J.; Dagaut, J.; Pepe, C.; Saliot, A. Identification of the Position and the Stereochemistry of the Double Bond in Monounsaturated Fatty Acid Methyl Esters by Gas Chromatogra-phy/Mass Spectrometry of Dimethyl Disulfide Derivatives. Anal. Chem. 1988, 60, 928–931.

    Article  CAS  Google Scholar 

  70. Pepe, C.; Dif, K. The Use of Ethanethiol to Locate the Triple Bond in Alkynes and the Double Bond in Substituted Alkenes by Gas Chromatography/Mass Spectrometry. Rapid Commun. Mass Spectrom. 2001, 15, 97–103.

    Article  CAS  Google Scholar 

  71. Pepe, C.; Sayer, H.; Dagaut, J.; Couffignal, R. Determination of Double Bond Positions in Triunsaturated Compounds by Means of Gas Chromatography/Mass Spectrometry of Dimethyl Disulfide Derivatives. Rapid Commun. Mass Spectrom. 1997, 11, 919–921.

    Article  CAS  Google Scholar 

  72. Levsen, K.; Heimbach, H.; Shaw, G.J.; Milne, G.W.A. Isomerization of Hydrocarbon Ions. VIII. The Electron Impact Induced Decomposition of n-Dodecane. Org. Mass Spectrom. 1977, 12, 663–670.

    Article  CAS  Google Scholar 

  73. Lavanchy, A.; Houriet, R.; Gäumann, T. The Mass Spectrometric Fragmentation of n-Heptane. Org. Mass Spectrom. 1978, 13, 410–416.

    Article  CAS  Google Scholar 

  74. Lavanchy, A.; Houriet, R.; Gäumann, T. The Mass Spectrometric Fragmentation of n-Alkane. Org. Mass Spectrom. 1979, 14, 79–85.

    Article  CAS  Google Scholar 

  75. Levsen, K. Isomerization of Hydrocarbon Ions. I. Isomeric Octanes. Collisional Activation Study. Org. Mass Spectrom. 1975, 10, 43–54.

    Article  CAS  Google Scholar 

  76. Traeger, J.C.; McAdoo, D.J.; Hudson, C.E.; Giam, C.S. Why Are Alkane Eliminations From Ionized Alkanes So Abundant? J. Am. Chem. Soc. Mass Spectrom. 1998, 9,.21–28.

    Article  CAS  Google Scholar 

  77. McAdoo, D.J.; Bowen, R.D. Alkane Eliminations From Ions in the Gas Phase. Eur. Mass Spectrom. 1999, 5, 389–409.

    Article  CAS  Google Scholar 

  78. Olivella, S.; Solé, A.; McAdoo, D.J.; Griffin, L.L. Unimolecular Reactions of Ionized Alkanes: Theoretical Study of the Potential Energy Surface for CH3 and CH4 Losses From Ionized Butane and Isobutane. J. Am. Chem. Soc. 1994, 94, 11078–11088.

    Article  Google Scholar 

  79. Williams, D.H. A Transition State Probe. Accounts of Chemical Research 1977, 10, 280–286.

    Article  CAS  Google Scholar 

  80. Ludányi, K.; Dallos, A.; Kühn, Z.; Vékey, D. Mass Spectrometry of Very Large Saturated Hydrocarbons. J. Mass Spectrom. 1999, 34, 264–267.

    Article  Google Scholar 

  81. Biemann, K. Application of Mass Spectrometry in Organic Chemistry, Especially for Structure Determination of Natural Products. Angew. Chem. 1962, 74, 102–115.

    Article  CAS  Google Scholar 

  82. Happ, G.P.; Stewart, D.W. Rearrangement Peaks in the Mass Spectra of Certain Aliphatic Acids. J. Am. Chem. Soc. 1952, 74, 4404–4408.

    Article  CAS  Google Scholar 

  83. McLafferty, F.W. Mass Spectrometric Analysis. Broad Applicability to Chemical Research. Anal. Chem. 1956, 28, 306–316.

    Article  CAS  Google Scholar 

  84. McLafferty, F.W. Mass Spectrometric Analysis: Molecular Rearrangements. Anal. Chem. 1965, 31, 82–87.

    Article  Google Scholar 

  85. Kingston, D.G.I.; Bursey, J.T.; Bursey, M.M. Intramolecular Hydrogen Transfer in Mass Spectra. II. McLafferty Rearrangement and Related Reactions. Chem. Industry 1974, 74, 215–245.

    CAS  Google Scholar 

  86. Zollinger, M.; Scibl, J. McLafferty Reactions in Even-Electron Ions? Org. Mass Spectrom. 1985, 11, 649–661.

    Article  Google Scholar 

  87. Djerassi, C.; Tökés, L. Mass Spectrometry in Structural and Stereochemical Problems. XCm. Further Observations on the Importance of Interatomic Distance in the McLafferty Rearrangement. Synthesis and Fragmentation Behavior of Deuterium-Labeled 12-Oxo Steroids. J. Am. Chem. Soc. 1966, 88, 536–544.

    Article  CAS  Google Scholar 

  88. Djerassi, C.; von Mutzenbecher, G.; Fajkos, J.; Williams, D.H.; Budzikiewicz, H. Mass Spectrometry in Structural and Stereochemical Problems. LXV. Synthesis and Fragmentation Behavior of 15-Oxo Steroids. The Importance of Inter-Atomic Distance in the McLafferty Rearrangement. J. Am. Chem. Soc. 1965, 87, 817–826.

    Article  CAS  Google Scholar 

  89. Henion, J.D.; Kingston, D.G.I. Mass Spectrometry of Organic Compounds. IX. McLafferty Rearrangements in Some Bi-cyclic Ketones. J. Am. Chem. Soc. 1974, 96, 2532–2536.

    Article  CAS  Google Scholar 

  90. Stringer, M.B.; Underwood, D.J.; Bowie, J.H.; Allison, C.E.; Donchi, K.F.; Derrick, P.J. Is the McLafferty Rearrangement of Ketones Concerted or Stepwise? The Application of Kinetic Isotope Effects. Org. Mass Spectrom. 1992, 27, 270–276.

    Article  CAS  Google Scholar 

  91. Dewar, M.J.S. Multibond Reactions Cannot Normally Be Synchronous. J. Am. Chem. Soc. 1984, 106, 209–219.

    Article  CAS  Google Scholar 

  92. Holmes, J.L.; Lossing, F.P. Gas-Phase Heats of Formation of Keto and Enol Ions of Carbonyl Compounds. J. Am. Chem. Soc. 1980, 102, 1591–1595.

    Article  CAS  Google Scholar 

  93. Hrušák, J. MNDO Calculations on the Neutral and Cationic [CH3-CO-R] Systems in Relation to Mass Spectrometric Fragmentations. Z. Phys. Chem. 1991, 112, 217–226.

    Google Scholar 

  94. Beynon, J.H.; Saunders, R.A.; Williams, A.E. The High Resolution Mass Spectra of Aliphatic Esters. Anal. Chem. 1961, 33, 221–225.

    Article  CAS  Google Scholar 

  95. Harrison, A.G.; Jones, E.G. Rearrangement Reactions Following Electron Impact on Ethyl and Isopropyl Esters. Can. J. Chem. 1965, 43, 960–968.

    Article  CAS  Google Scholar 

  96. Wesdemiotis, C.; Feng, R.; McLafferty, F.W. Distonic Radical Ions. Stepwise Elimination of Acetaldehyde From Ionized Benzyl Ethyl Ether. J. Am. Chem. Soc. 1985, 101, 715–716.

    Article  Google Scholar 

  97. Kingston, E.E.; Eichholzer, J.V.; Lyndon, P.; McLeod, J.K.; Summons, R.E. An Unexpected y-Hydrogen Rearrangement in the Mass Spectra of Di-Ortho-Substituted Alkylbenzenes. Org. Mass Spectrom. 1988, 23, 42–47.

    Article  CAS  Google Scholar 

  98. Benoit, F.M.; Harrison, A.G. Hydrogen Migrations in Mass Spectrometry. H. Single and Double Hydrogen Migrations in the Electron Impact Fragmentation of Propyl Benzoate. Org. Mass Spectrom. 1976, 1056–1062.

    Google Scholar 

  99. Müller, J.; Krebs, G.; Lüdemann, F.; Baumgartner, E. Wasserstoff-Umlagerungen Beim Elektronenstoß-Induzierten Zerfall Von η6-Benzoesäure-n-Propylester-Tricarbonylchrom. J. Organomet. Chem. 1981, 218, 61–68.

    Article  Google Scholar 

  100. Benoit, F.M.; Harrison, A.G.; Lossing, F.P. Hydrogen Migrations in Mass Spectrometry. III. Energetics of Formation of [R’CO2H2]+ in the Mass Spectra of R’CO2R. Org. Mass Spectrom. 1977, 12, 78–82.

    Article  CAS  Google Scholar 

  101. Tajima, S.; Azami, T.; Shizuka, H.; Tsuchiya, T. An Investigation of the Mechanism of Single and Double Hydrogen Atom Transfer Reactions in Alkyl Benzo-ates by the Ortho Effect. Org. Mass Spectrom. 1979, 14, 499–502.

    Article  CAS  Google Scholar 

  102. Meyerson, S. Formation of [C18H36]+ and [C7H7O2]+ in the Mass Spectrum of n-Octadecyl Benzoate. Org. Mass Spectrom. 1989, 24, 652–662.

    Google Scholar 

  103. Elder, J.F., Jr.; Beynon, J.H.; Cooks, R.G. The Benzoyl Ion. Thermochemistry and Kinetic Energy Release. Org. Mass Spectrom. 1976, 11, 415–422.

    Article  CAS  Google Scholar 

  104. McLafferty, F.W.; Gohlke, R.S. Mass Spectrometric Analysis-Aromatic Acids and Esters. Anal Chem. 1959, 31, 2076–2082.

    Article  CAS  Google Scholar 

  105. Yinon, J. Mass Spectral Fragmentation Pathways in Phthalate Esters. A Tandem Mass Spectrometric Collision-Induced Dissociation Study. Org. Mass Spectrom. 1988, 23, 755–759.

    Article  CAS  Google Scholar 

  106. Djerassi, C.; Fenselau, C. Mass Spectrometry in Structural and Stereochemical Problems. LXXXVI. The Hydrogen-Transfer Reactions in Butyl Propionate, Benzoate, and Phthalate. J. Am. Chem. Soc. 1965, 87, 5756–5762.

    Article  CAS  Google Scholar 

  107. Turecek, F.; Hanus, V. Retro-Diels-Alder Reaction in Mass Spectrometry. Mass Spectrom. Rev. 1984, 3, 85–152.

    Article  CAS  Google Scholar 

  108. Turecek, F.; Hanus, V. Charge Distribution Between Formally Identical Fragments: the Retro-Diels-Alder Cleavage. Org. Mass Spectrom. 1980, 75, 4–7.

    Article  Google Scholar 

  109. Kühne, H.; Hesse, M. The Mass Spectral Retro-Diels-Alder Reaction of 1,2,3,4-Tetrahydronaphthalene, Its Derivatives and Related Heterocyclic Compounds. Mass Spectrom. Rev. 1982, 1, 15–28.

    Article  Google Scholar 

  110. Budzikiewicz, H.; Brauman, J.I.; Djerassi, C. Mass Spectrometry and Its Application to Structural and Stereochemical Problems. LXVII. Retro-Diels-Alder Fragmentation of Organic Molecules Under Electron Impact. Tetrahedron 1965, 21, 1855–1879.

    Article  CAS  Google Scholar 

  111. Karpati, A.; Rave, A.; Deutsch, J.; Mandelbaum, A. Stereospecificity of Retro-Diels-Alder Fragmentation Under Electron Impact. J. Am. Chem. Soc. 1973, 90, 4244.

    Article  Google Scholar 

  112. Hammerum, S.; Djerassi, C. Mass Spectrometry in Structural and Stereochemical Problems. CCXXXIII. Stereochemical Dependence of the Retro-Diels-Alder Reaction. J. Am. Chem. Soc. 1973, 95, 5806–5807.

    Article  CAS  Google Scholar 

  113. Djerassi, C. Steroids Made It Possible: Organic Mass Spectrometry. Org. Mass Spectrom. 1992, 27, 1341–1347.

    Article  CAS  Google Scholar 

  114. Dixon, J.S.; Midgley, I.; Djerassi, C. Mass Spectrometry in Structural and Stereochemical Problems. 248. Stereochemical Effects in Electron Impact Induced Retro-Diels-Alder Fragmentations. J. Am. Chem. Soc. 1977, 99, 3432–3441.

    Article  CAS  Google Scholar 

  115. Barnes, C.S.; Occolowitz, J.L. Mass Spectra of Some Naturally Occurring Oxygen Heterocycles and Related Compounds. Aust. J. Chem. 1964, 17, 975–986.

    Article  CAS  Google Scholar 

  116. Ardanaz, C.E.; Guidugli, F.H.; Catalán, C.A.N.; Joseph-Nathan, P. Mass Spectral Studies of Methoxynaphthoflavones. Rapid Commun. Mass Spectrom. 1999, 13, 2071–2079.

    Article  CAS  Google Scholar 

  117. Ballenweg, S.; Gleiter, R.; Krätschmer, W. Chemistry at Cyclopentene Addends on [60]Fullerene. Matrix-Assisted Laser De-sorption-Ionization Time-of-Flight Mass Spectrometry As a Quick and Facile Method for the Characterization of Fullerene Derivatives. Synth. Met. 1996, 11, 209–212.

    Article  Google Scholar 

  118. Ballenweg, S.; Gleiter, R.; Krätschmer, W. Unusual Functionalization of C6o Via Hy-drozirconation: Reactivity of the C60-Zr(IV) Complex Vs. Alkyl-Zr(IV) Complexes. J. Chem. Soc., Chem. Commun. 1994, 2269–2270.

    Google Scholar 

  119. Aczel, T.; Lumpkin, H.E. Correlation of Mass Spectra With Structure in Aromatic Oxygenated Compounds. Aromatic Alcohols and Phenols. Anal. Chem. 1960, 32, 1819–1822.

    Article  CAS  Google Scholar 

  120. Beynon, J.H. Correlation of Molecular Structure and Mass Spectra, in Mass Spectrometry and its Applications to Organic Chemistry, 1st ed.; Elsevier: Amsterdam, 1960; pp. 352.

    Google Scholar 

  121. Beynon, J.H.; Lester, G.R.; Williams, A.E. Specific Molecular Rearrangements in the Mass Spectra of Organic Compounds. J. Phys. Chem. 1959, 63, 1861–1869.

    Article  CAS  Google Scholar 

  122. Momigny, J. The Mass Spectra of Mono-substituted Benzene Derivatives. Phenol, Monodeuteriophenol, Thiophenol, and Aniline. Bull. Soc. RoyalSci. Liège 1953, 22, 541–560.

    CAS  Google Scholar 

  123. Occolowitz, J.L. Mass Spectrometry of Naturally Occurring Alkenyl Phenols and Their Derivatives. Anal. Chem. 1964, 36, 2177–2181.

    Article  CAS  Google Scholar 

  124. Stensen, W.G.; Jensen, E. Structural Determinationof 1,4-Naphthoquinones by Mass Spectrometry/Mass Spectrometry. J. Mass Spectrom. 1995, 30, 1126–1132.

    Article  CAS  Google Scholar 

  125. Guigugli, F.H.; Kavka, J.; Garibay, M.E.; Santillan, R.L.; Joseph-Nathan, P. Mass Spectral Studies of Naphthoflavones. Org. Mass Spectrom. 1987, 22, 479–485.

    Article  Google Scholar 

  126. Pelan, Z.; Wilson, J.M.; Ohashi, M.; Budzikiewicz, H.; Djerassi, C. Mass Spectrometry in Structural and Stereochemical Problems. XXXIV. Aromatic Methyl and Ethyl Ethers. Tetrahedron 1963, 19, 2233–2240.

    Article  Google Scholar 

  127. Molenaar-Langeveld, T.A.; Ingemann, S.; Nibbering, N.M.M. Skeletal Rearrangements Preceding Carbon Monoxide Loss From Metastable Phenoxymethylene Ions Derived From Phenoxyacetic Acid and Anisole. Org. Mass Spectrom. 1993, 28, 1167–1178.

    Article  CAS  Google Scholar 

  128. Zagorevskii, D.V.; Regimbai, J.-M.; Holmes, J.L. The Heat of Formation of the [C6,H5,O]+ Isomeric Ions. Int. J. Mass Spectrom. Ion Proc. 1997, 160 , 211–222.

    Article  CAS  Google Scholar 

  129. Cooks, R.G.; Bertrand, M.; Beynon, J.H.; Rennekamp, M.E.; Setser, D.W. Energy Partitioning Data As an Ion Structure Probe. Substituted Anisoles. J. Am. Chem. Soc. 1973, 95, 1732–1739.

    Article  CAS  Google Scholar 

  130. Alexander, J.J. Mechanism of Photochemical Decarbonylation of Acetyldicar-bonyl-η5-Cyclopentadienyliron. J. Am. Chem. Soc. 1975, 97, 1729–1732.

    Article  CAS  Google Scholar 

  131. Coville, N.J.; Johnston, P. A Mass-Spectral Investigation of Site-Selective Carbon Monoxide Loss From Isotopically Labeled [MnRe(CO)10]+. J. Organomet. Chem. 1989, 363, 343–350.

    Article  CAS  Google Scholar 

  132. Tobita, S.; Ogino, K.; Ino, S.; Tajima, S. On the Mechanism of Carbon Monoxide Loss From the Metastable Molecular Ion of Dimethyl Malonate. Int. J. Mass Spectrom. Ion Proc. 1988, 85, 31–42.

    Article  CAS  Google Scholar 

  133. Moldovan, Z.; Palibroda, N.; Mercea, V.; Mihailescu, G.; Chiriac, M.; Vlasa, M. Mass Spectra of Some β-Keto Esters. A High Resolution Study. Org. Mass Spectrom. 1981, 16, 195–198.

    Article  CAS  Google Scholar 

  134. Vairamani, M.; Mirza, U.A. Mass Spectra of Phenoxyacetyl Derivatives. Mechanism of Loss of CO From Phenyl Phenoxyace-tates. Org. Mass Spectrom. 1987, 22, 406–409.

    Article  CAS  Google Scholar 

  135. Tajima, S.; Siang, L.F.; Fuji-Shige, M.; Nakajima, S.; Sekiguchi, O. Collision-Induced Dissociation Spectra Versus Collision Energy Using a Quadrupole Ion Trap Mass Spectrometer. II. Loss of CO From Ionized o-, m- and p-Anisoyl Fluoride, CH3OC6H4COF+ J. Mass Spectrom. 2000, 35, 1144–1146.

    Article  CAS  Google Scholar 

  136. Tajima, S.; Tobita, S.; Mitani, M.; Akuzawa, K.; Sawada, H.; Nakayama, M. Loss of CO From the Molecular Ions of o-, m-and p-Anisoyl Fluorides, CH3OC6H4COF, With Fluorine Atom Migration. Org. Mass Spectrom. 1991, 26, 1023–1026.

    Article  CAS  Google Scholar 

  137. Tou, J.C. Competitive and Consecutive Eliminations of Molecular Nitrogen and Carbon Monoxide (or Ethene) From Heterocyclics Under Electron Impact. J. Het-erocycl. Chem. 1974, 11, 707–711.

    Article  CAS  Google Scholar 

  138. McFadden, W.H.; Lounsbury, M.; Wahrhaftig, A.L. The Mass Spectra of Three Deuterated Butanols. Can. J. Chem. 1958, 36, 990–998.

    Article  CAS  Google Scholar 

  139. Bukovits, G.J.; Budzikiewicz, H. Mass Spectroscopic Fragmentation Reactions. XXVIII. The Loss of Water From n-Alkan-1-ols. Org. Mass Spectrom. 1983, 18, 219–220.

    Article  CAS  Google Scholar 

  140. Meyerson, S.; Leitch, L.C. Organic Ions in the Gas Phase. XIV. Loss of Water From Primary Alcohols Under Electron Impact. J. Am. Chem. Soc. 1964, 86, 2555–2558.

    Article  CAS  Google Scholar 

  141. Bowen, R.D. The Role of Ion-Neutral Complexes in the Reactions of Onium Ions and Related Species. Org. Mass Spectrom. 1993, 28, 1577–1595.

    Article  CAS  Google Scholar 

  142. Bowen, R.D. Potential Energy Profiles for Unimolecular Reactions of Isolated Organic Ions: Some Isomers of [C4H10N]+ and [C5H12N]+. J. Chem. Soc., Perkin Trans.2 1980, 1219–1227.

    Google Scholar 

  143. Bowen, R.D.; Derrick, P.J. Unimolecular Reactions of Isolated Organic Ions: the Chemistry of the Oxonium Ions [CH3CH2CH2CH2O=CH2]+ and [CH3CH2CH2CH=OCH3]+. Org. Mass Spectrom. 1993, 28, 1197–1209.

    Article  CAS  Google Scholar 

  144. Soiling, T.I.; Hammerum, S. The Retro-Ene Reaction of Gaseous Immonium Ions Revisited. J. Chem. Soc., Perkin Trans. 2 2001, 2324–2428.

    Google Scholar 

  145. Veith, HJ.; Gross, J.H. Alkene Loss From Metastable Methyleneimmonium Ions: Unusual Inverse Secondary Isotope Effect in Ion-Neutral Complex Intermediate Fragmentations. Org. Mass Spectrom. 1991, 26, 1097–1105.

    Article  CAS  Google Scholar 

  146. Budzikiewicz, H.; Bold, P. A McLafferty Rearrangement in an Even-Electron System: C3H6 Elimination From the α-Cleavage Product of Tributylamine. Org. Mass Spectrom. 1991, 26, 709–712.

    Article  CAS  Google Scholar 

  147. Bowen, R.D.; Colburn, A.W.; Derrick, P.J. Unimolecular Reactions of Isolated Organic Ions: Reactions of the Immonium Ions [CH2=N(CH3)CH(CH3)2]+. [CH2=N(CH3)CH2CH2CH3]+ and [CH2=N(CH2CH2CH3)2]+. J. Chem. Soc., Perkin Trans.2 1993, 2363–2372.

    Google Scholar 

  148. Gross, J.H.; Veith, H.J. Propene Loss From Phenylpropylmethyleneiminium Ions. Org. Mass Spectrom. 1994, 29, 153–154.

    Article  CAS  Google Scholar 

  149. Gross, J.H.; Veith, H.J. Unimolecular Fragmentations of Long-Chain Aliphatic Iminium Ions. Org. Mass Spectrom. 1993, 28, 867–872.

    Article  CAS  Google Scholar 

  150. Uccella, N.A.; Howe, I.; Williams, D.H. Structure and Isomerization of Gaseous [C3H8N]+ Metastable Ions. J. Chem. Soc., B l971, 1933–1939.

    Google Scholar 

  151. Levsen, K.; Schwarz, H. Influence of Charge Localization on the Isomerization of Organic Ions. Tetrahedron 1975, 31, 2431–2433.

    Article  CAS  Google Scholar 

  152. Bowen, R.D. Unimolecular Reactions of Isolated Organic Ions: Olefin Elimination From Immonium Ions [R1R2N=CH2]+. J. Chem. Soc., Perkin Trans.2 1982, 409–413.

    Google Scholar 

  153. Bowen, R.D. Reactions of Isolated Organic Ions. Alkene Loss From the Immonium Ions [CH3CH=NHC2H5]+ and [CH3CH=NHC3H7]+. J. Chem. Soc., Perkin Trans.2 1989, 913–918.

    Google Scholar 

  154. Bowen, R.D.; Colburn, A.W.; Derrick, P.J. Unimolecular Reactions of the Isolated Immonium Ions [CH3CH=NHC4H9]+, [CH3CH2CH=NHC4H9]+ and [(CH3)2C=NHC4H9]+. Org. Mass Spectrom. 1990, 25, 509–516.

    Article  CAS  Google Scholar 

  155. Bowen, R.D.; Maccoll, A. Unimolecular Reactions of Ionized Ethers. J. Chem. Soc., Perkin Trans. 2 1990, 147–155.

    Google Scholar 

  156. Traeger, J.C.; Hudson, C.E.; McAdoo, D.J. Energy Dependence of Ion-Induced Dipole Complex-Mediated Alkane Eliminations From Ionized Ethers. J. Phvs. Chem. 1990, 94, 5714–5717.

    Article  CAS  Google Scholar 

  157. Bowen, R.D.; Williams, D.H. Non-Concerted Unimolecular Reactions of Ions in the Gas-Phase: the Importance of Ion-Dipole Interactions in Carbonium Ion Isomerizations. Int. J. Mass Spectrom. Ion Phys. 1979, 29, 47–55.

    Article  CAS  Google Scholar 

  158. Bowen, R.D.; Williams, D.H. Unimolecular Reactions of Isolated Organic Ions. The Importance of Ion-Dipole Interactions. J. Am. Chem. Soc 1980, 102, 2752–2756.

    Article  CAS  Google Scholar 

  159. Bowen, R.D. Potential Energy Profiles for Unimolecular Reactions of Isolated Organic Ions: [EtCH=NHMe]+ and [Me2C=NHMe]+. J. Chem. Soc., Perkin Trans. 2 1982, 403–408.

    CAS  Google Scholar 

  160. Bowen, R.D.; Derrick, P.J. The Mechanism of Ethylene Loss From the Oxonium Ion [CH3CH2O=CHCH2CH3]+. J. Chem. Soc., Chem. Commun. 1990, 1539–1541.

    Google Scholar 

  161. Bowen, R.D.; Colburn, A.W.; Derrick, P.J. Unimolecular Reactions of Isolated Organic Ions: Chemistry of the Unsaturated Oxonium Ion [CH2=CHCH=OCH3] +. Org. Mass Spectrom. 1992, 27, 625–632.

    Article  CAS  Google Scholar 

  162. Bowen, R.D.; Derrick, P.J. The Mechanism of Ethylene Elimination From the Oxonium Ions [CH3CH2CH=OCH2CH3]+ and [(CH3)2C=OCH2CH3]+. J. Chem. Soc., Perkin Trans. 2 1992, 1033–1039.

    Google Scholar 

  163. Nguyen, M.T.; Vanquickenborne, L.G.; Bouchoux, G. On the Energy Barrier for 1,2-Elimination of Methane From Di-methyloxonium Cation. Int. J. Mass Spectrom. Ion Proc 1993, 124, R11–R14.

    Article  Google Scholar 

  164. Lias, S.G.; Liebman, J.F.; Levin, R.D. Evaluated Gas Phase Basicities and Proton Affinities of Molecules; Heats of Formation of Protonated Molecules. J. Phys. Chem. Ref. Data 1984, 13, 695–808.

    Article  CAS  Google Scholar 

  165. Lias, S.G.; Bartmess, J.E.; Liebman, J.F.; Holmes, J.L.; Levin, R.D.; Mallard, W.G. Gas-Phase Ion and Neutral Thermochemistry. J. Phys. Chem. Ref. Data 1988, 17, Supplement 1, 861 pp.

    Google Scholar 

  166. Hunter, E.P.L.; Lias, S.G. Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update. J. Phys. Chem. Ref. Data 1998, 27, 413–656.

    Article  CAS  Google Scholar 

  167. Bowen, R.D.; Stapleton, B.J.; Williams, D.H. Nonconcerted Unimolecular Reactions of Ions in the Gas Phase: Isomerization of Weakly Coordinated Carbonium Ions. J. Chem. Soc., Chem. Commun. 1978, 24–26.

    Google Scholar 

  168. Morton, T.H. Gas Phase Analogues of Solvolysis Reactions. Tetrahedron 1982, 38, 3195–3243.

    Article  CAS  Google Scholar 

  169. Morton, T.H. The Reorientation Criterion and Positive Ion-Neutral Complexes. Org. Mass Spectrom. 1992, 27, 353–368.

    Article  CAS  Google Scholar 

  170. Longevialle, P. Ion-Neutral Complexes in the Unimolecular Reactivity of Organic Cations in the Gas Phase. Mass Spectrom. Rev. 1992, 11, 157–192.

    Article  CAS  Google Scholar 

  171. McAdoo, D.J. Ion-Neutral Complexes in Unimolecular Decompositions. Mass Spectrom. Rev. 1988, 7, 363–393.

    Article  CAS  Google Scholar 

  172. Rylander, P.N.; Meyerson, S. Organic Ions in the Gas Phase. I. The Cationated Cyclopropane Ring. J. Am. Chem. Soc. 1956, 78, 5799–5802.

    Article  CAS  Google Scholar 

  173. Meyerson, S. Cationated Cyclopropanes As Reaction Intermediates in Mass Spectra: an Earlier Incarnation of Ion-Neutral Complexes. Org. Mass Spectrom. 1989, 24, 267–270.

    Article  CAS  Google Scholar 

  174. Bowen, R.D.; Williams, D.H.; Hvistendahl, G.; Kaiman, J.R. Potential Energy Profiles for Unimolecular Reactions of Organic Ions: [C3H8N]+ and [C3H70]+. Org. Mass Spectrom. 1978, 13, 721–728.

    Article  CAS  Google Scholar 

  175. Longevialle, P.; Botter, R. Electron Impact Mass Spectra of Bifunctional Steroids. The Interaction Between Ionic and Neutral Fragments Derived From the Same Parent Ion. Org. Mass Spectrom. 1983, 18, 1–8.

    Article  CAS  Google Scholar 

  176. Longevialle, P.; Botter, R. The Interaction Between Ionic and Neutral Fragments From the Same Parent Ion in the Mass Spectrometer. Int. J. Mass Spectrom. Ion Phys. 1983, 47, 179–182.

    Article  CAS  Google Scholar 

  177. Redman, E.W.; Morton, T.H. Product-Determining Steps in Gas-Phase Broen-sted Acid-Base Reactions. Deprotonation of 1-Methylcyclopentyl Cation by Amine Bases. J. Am. Chem. Soc. 1986,108, 5701–5708.

    Article  CAS  Google Scholar 

  178. Fuges, U.; Grützmacher, H.-F. Fragmentations of Protonated Benzaldehydes Via Intermediate Ion/Molecule Complexes. Org. Mass Spectrom. 1986, 21, 673–680.

    Article  Google Scholar 

  179. Hudson, C.E.; McAdoo, D.J. Alkane Eliminations From Radical Cations Through Ion-Radical Complexes. Int. J. Mass Spectrom. Ion Proc. 1984, 59, 325–332.

    Article  CAS  Google Scholar 

  180. McAdoo, D.J.; Hudson, C.E. Ion-Neutral Complex-Mediated Hydrogen Exchange in Ionized Butanol: a Mechanism for Nonspecific Hydrogen Migration. Org. Mass Spectrom. 1987, 22, 615–621.

    Article  CAS  Google Scholar 

  181. Hammerum, S. Formation and Stabilization of Intermediate Ion-Neutral Complexes in Radical Cation Dissociation Reactions. J. Chem. Soc., Chem. Commun. 1988, 858–859.

    Google Scholar 

  182. Hammerum, S.; Audier, H.E. Experimental Verification of the Intermediacy and Interconversion of Ion-Neutral Complexes As Radical Cations Dissociate. J. Chem. Soc., Chem. Commun. 1988, 860–861.

    Google Scholar 

  183. Traeger, J.C.; Hudson, C.E.; McAdoo, D.J. Isomeric Ion-Neutral Complexes Generated From Ionized 2-Methyl-propanol and n-Butanol: the Effect of the Polarity of the Neutral Partner on Complex-Mediated Reactions. J. Am. Chem. Soc Mass Spectrom. 1991, 3, 409–416.

    Article  Google Scholar 

  184. Sozzi, G.; Audier, H.E.; Mourgues, P.; Milliet, A. Alkyl Phenyl Ether Radical Cations in the Gas Phase: a Reaction Model. Org. Mass Spectrom. 1987, 22, 746–747.

    Article  CAS  Google Scholar 

  185. Morton, T.H. Ion-Molecule Complexes in Unimolecular Fragmentations of Gaseous Cations. Alkyl Phenyl Ether Molecular Ions. J. Am. Chem. Soc 1980, 102, 1596–1602.

    Article  CAS  Google Scholar 

  186. Blanchette, M. C.; Holmes, J.L.; Lossing, F.P. The Fragmentation of Ionized Alkyl Phenyl Ethers. Org. Mass Spectrom. 1989, 24, 673–678.

    Article  CAS  Google Scholar 

  187. Harnish, D.; Holmes, J.L. Ion-Radical Complexes in the Gas Phase: Structure and Mechanism in the Fragmentation of Ionized Alkyl Phenyl Ethers. J. Am. Chem. Soc. 1991, 113, 9729–9734.

    Article  CAS  Google Scholar 

  188. Zappey, H.W.; Ingemann, S.; Nibbering, N.M.M. Isomerization and Fragmentation of Aliphatic Thioether Radical Cations in the Gas Phase: Ion-Neutral Complexes in the Reactions of Metastable Ethyl Propyl Thioether Ions. J. Chem. Soc., Perkin Trans. 2 1991, 1887–1892.

    Google Scholar 

  189. Broer, W.J.; Weringa, W.D. Potential Energy Profiles for the Unimolecular Reactions of [C3H7S]+ Ions. Org. Mass Spectrom. 1980, 229–234.

    Google Scholar 

  190. Schwarz, H. Some Newer Aspects of Mass Spectrometric Ortho Effects. Top. Curr. Chem. 1978, 73, 231–263.

    Article  CAS  Google Scholar 

  191. Meyerson, S.; Drews, H.; Field, E.K. Mass Spectra of Ortho-Substituted Diaryl-methanes. J. Am. Chem. Soc. 1964, 86, 4964–4967.

    Article  CAS  Google Scholar 

  192. Laseter, J.L.; Lawler, G. C.; Griffin, G.W. Influence of Methyl Substitution on Mass Spectra of Diphenylmethanes. Analytical Applications. Anal. Lett. 1973, 6, 735–744.

    Article  CAS  Google Scholar 

  193. Martens, J.; Praefcke, K.; Schwarz, H. Spectroscopic Investigations. IX. Analytical Importance of the Ortho Effect in Mass Spectrometry. Benzoic and Thiobenzoic Acid Derivatives. Z. Naturforsch., B 1975, 30, 259–262.

    Google Scholar 

  194. Grützmacher, H.-F. Mechanisms of Mass Spectrometric Fragmentation Reactions. XXXII. The Loss of Ortho Halo Substitu-ents From Substituted Thiobenzamide Ions. Org. Mass Spectrom. 1981, 16, 448–450.

    Article  Google Scholar 

  195. Ramana, D.V.; Sundaram, N. Ortho Effects in Organic Molecules on Electron Impact. X. Unusual Ortho Effects of the Methyl Group in o-Picolinotoluidide. Org. Mass Spectrom. 1982, 17, 465–469.

    Article  CAS  Google Scholar 

  196. Ramana, D.V.; Sundaram, N.; George, N. Ortho Effects in Organic Molecules on Electron Impact. 14. Concerted and Stepwise Ejections of SO2 and N2 From N-Arylidene-2-nitrobenzenesulfenamides. Org. Mass Spectrom. 1987, 22, 140–144.

    Article  CAS  Google Scholar 

  197. Sekiguchi, O.; Noguchi, T.; Ogino, K.; Tajima, S. Fragmentation of Metastable Molecular Ions of Acetylanisoles. Int. J. Mass Spectrom. Ion Proc. 1994, 132, 172–179.

    Article  Google Scholar 

  198. Barkow, A.; Pilotek, S.; Grützmacher, H.-F. Ortho Effects: a Mechanistic Study. Eur. Mass Spectrom. 1995, 1, 525–537.

    Article  CAS  Google Scholar 

  199. Danikiewicz, W. Ortho Interactions During Fragmentation of N-(2-Nitrophenyl)methanesulfonamide and Its N-Alkyl Derivatives Upon Electron Ionization. Eur. Mass Spectrom. 1997, 3, 209–216.

    Article  CAS  Google Scholar 

  200. Danikiewicz, W. Electron Ionization-Induced Fragmentation of N-Alkyl-o-Nitroanilines: Observation of New Types of Ortho Effects. Eur. Mass Spectrom. 1998, 4, 167–179.

    Article  CAS  Google Scholar 

  201. Spiteller, G. The Ortho Effect in the Mass Spectra of Aromatic Compounds. Monatsh. Chem. 1961, 92, 1147–1154.

    Article  Google Scholar 

  202. Smith, J.G.; Wilson, G.L.; Miller, J.M. Mass Spectra of Isopropyl Benzene Derivatives. A Study of the Ortho Effect. Org. Mass Spectrom. 1975, 10, 5–17.

    Article  CAS  Google Scholar 

  203. Schwarz, H.; Koppel, C.; Bohlmann, F. Electron Impact-Induced Fragmentation of Acetylene Compounds. XII. Rearrangement of Bis(Trimethylsilyl) Ethers of Unsaturated α,ω-Diols and Mass Spectrometric Identification of Isomeric Phenols. Tetrahedron 1974, 30, 689–693.

    Article  CAS  Google Scholar 

  204. Svendsen, J.S.; Sydnes, L.K.; Whist, J.E. Mass Spectrometric Study of Dimethyl Esters of Trimethylsilyl Ether Derivatives of Some 3-Hydroxy Dicarboxylic Acids. Org. Mass Spectrom. 1987, 22, 421–429.

    Article  CAS  Google Scholar 

  205. Svendsen, J.S.; Whist, J.E.; Sydnes, L.K. A Mass Spectrometric Study of the Dimethyl Ester Trimethylsilyl Enol Ether Derivatives of Some 3-Oxodicarboxylic Acids. Org. Mass Spectrom. 1987, 22, 486–492.

    Article  CAS  Google Scholar 

  206. Poole, C.F. Recent Advances in the Si-lylation of Organic Compounds for Gas Chromatography, in Handbook of dérivâtes for chromatography, 1st ed.; Blau, G.; King, G.S., editors; Heyden & Son: London, 1977; Chapter 4, pp. 152–200.

    Google Scholar 

  207. Halket, H.M.; Zaikin, V.G. Derivatization in Mass Spectrometry -1. Silylation. Eur. J. Mass Spectrom. 2003, 9, 1–21.

    Article  CAS  Google Scholar 

  208. Beynon, J.H.; Bertrand, M.; Cooks, R.G. Metastable Loss of Nitrosyl Radical From Aromatic Nitro Compounds. J. Am. Chem. Soc. 1973, 95, 1739–1745.

    Article  CAS  Google Scholar 

  209. McLuckey, S.A.; Glish, G.L. The Effect of Charge on Hydroxyl Loss From Ortho-Substituted Nitrobenzene Ions. Org. Mass Spectrom. 1987, 22, 224–228.

    Article  CAS  Google Scholar 

  210. Beynon, J.H.; Saunders, R.A.; Topham, A.; Williams, A.E. The Dissociation of o-Nitrotoluene Under Electron Impact. J.Chem. Soc. 1965, 6403–6405.

    Google Scholar 

  211. Herbert, C.G.; Larka, E.A.; Beynon, J.H. The Elimination of Masses 27 and 28 From the [M-OH]+ Ion of 2-Nitrotoluene. Org. Mass Spectrom. 1984, 19, 306–310.

    Article  CAS  Google Scholar 

  212. Meyerson, S.; Puskas, I.; Fields, E.K. Organic Ions in the Gas Phase. XVIII. Mass Spectra of Nitroarenes. J. Am. Chem. Soc. 1966, 88, 4974–4908.

    Article  CAS  Google Scholar 

  213. Riley, J.S.; Baer, T.; Marbury, G.D. Sequential Ortho Effects: Characterization of Novel [M-35]+ Fragment Ions in the Mass Spectra of 2-Alkyl-4,6-Dinitrophenols. J. Am. Chem. Soc. Mass Spectrom. 1991, 2, 69–75.

    Article  CAS  Google Scholar 

  214. Yinon, J. Mass Spectral Fragmentation Pathways in 2,4,6-Trinitroaromatic Compounds. A Tandem Mass Spectrometric Collision-Induced Dissociation Study. Org. Mass Spectrom. 1987, 22, 501–505.

    Article  CAS  Google Scholar 

  215. Porter, Q.N.; Baldas, J. Mass Spectrometry of Heterocyclic Compounds; 1st ed.; Wiley Interscience: New York, 1971.

    Google Scholar 

  216. Schwarz, H.; Bohlmann, F. Mass Spectrometric Investigation of Amides. II. Electron-Impact Induced Fragmentation of (Phenylacetyl)Aziridine, -Pyrrolidine, and -Piperidine. Tetrahedron Lett. 1973, 38, 3703–3706.

    Article  Google Scholar 

  217. Nakano, T.; Martin, A. Mass Spectrometric Fragmentation of the Oxetanes of 3,5-Dimethylisoxazole, 2,4-Dimethylthiazole, and 1-Acetylimidazole. Org. Mass Spectrom. 1981, 16, 55–61.

    Article  CAS  Google Scholar 

  218. Grützmacher, H.-F.; Pankoke, D. Rearrangement Reactions of the Molecular Ions of Some Substituted Aliphatic Oxira-nes. Org. Mass Spectrom. 1989, 24 , 647–652.

    Article  Google Scholar 

  219. Collin, J.E.; Conde-Caprace, G. Ionization and Dissociation of Cyclic Ethers by Electron Impact. Int. J. Mass Spectrom. Ion Phys. 1968, 1, 213–225.

    Article  CAS  Google Scholar 

  220. Duffieid, A.M.; Budzikiewicz, H.; Williams, D.H.; Djerassi, C. Mass Spectrometry in Structural and Stereochemical Problems. LXIV. A Study of the Fragmentation Processes of Some Cyclic Amines. J. Am. Chem. Soc. 1965, 87, 810–816.

    Article  Google Scholar 

  221. Burgers, P.C.; Holmes, J.L.; Mommers, A.A.; Terlouw, J.K. Neutral Products of Ion Fragmentations: Hydrogen Cyanide and Hydrogen Isocyanide (HNC) Identified by Collisionally Induced Dissociative Ionization. Chem. Phys. Lett. 1983, 102, 1–3.

    Article  CAS  Google Scholar 

  222. Hop, C.E.C.A.; Dakubu, M.; Holmes, J.L. Do the Aminopyridine Molecular Ions Display Aniline- or Pyridine-Type Behavior? Org. Mass Spectrom. 1988, 23, 609–612.

    Article  CAS  Google Scholar 

  223. Rosenstock, H.M.; Stockbauer, R.; Parr, A.C. Unimolecular Kinetics of Pyridine Ion Fragmentation. Int. J. Mass Spectrom. Ion Phys. 1981, 38, 323–331.

    Article  CAS  Google Scholar 

  224. Burgers, P.C.; Holmes, J.L. Kinetic Energy Release in Metastable-Ion Fragmentations. Rapid Commun. Mass Spectrom. 1989, 2, 279–280.

    Article  Google Scholar 

  225. Cardoso, A.M.; Ferrer, A.J. Fragmentation Reactions of Molecular Ions and Dications of Indoleamines. Eur. Mass Spectrom. 1999 , 5, 11–18.

    Article  CAS  Google Scholar 

  226. Rodríguez, J.G.; Urrutia, A.; Canoira, L. Electron Impact Mass Spectrometry of Indole Derivatives. Int. J. Mass Spectrom. Ion Proc. 1996, 152, 97–110.

    Article  Google Scholar 

  227. Hesse, M. Indolalkaloide, Teil I: Text; 1st ed.; VCH: Weinheim, 1974.

    Google Scholar 

  228. Hesse, M. Indolalkaloide, Teil 2: Spektren; 1st ed.; VCH: Weinheim, 1974.

    Google Scholar 

  229. Biemann, K. Four Decades of Structure Determination by Mass Spectrometry: From Alkaloids to Heparin. J. Am. Chem. Soc. Mass Spectrom. 2002, 13, 1254–1272.

    Article  CAS  Google Scholar 

  230. Duffieid, A.M.; Beugelmans, R.; Budzikiewicz, H.; Lightner, D.A.; Williams, D.H.; Djerassi, C. Mass Spectrometry in Structural and Stereochemical Problems. LXIII. Hydrogen Rearrangements Induced by Electron Impact on N-n-Butyl- and N-n-Pentylpyrroles. J. Am. Chem. Soc. 1965, 87, 805–810.

    Article  Google Scholar 

  231. Aubagnac, J.L.; Campion, P. Mass Spectrometry of Nitrogen Heterocycles. X. Contribution to the Behavior of the Aniline Ion and Aminopyridine Ions Prior to Fragmentation by Loss of Hydrogen Cyanide. Org. Mass Spectrom. 1979, 14, 425–429.

    Article  CAS  Google Scholar 

  232. Heyns, K.; Stute, R.; Scharmann, H. Mass Spectrometric Investigations. XII. Mass Spectra of Furans. Tetrahedron 1966, 22, 2223–2235.

    Article  CAS  Google Scholar 

  233. De Jong, F.; Sinnige, H.J.M.; Janssen, M.J. Carbon Scrambling in Thiophene Under Electron Impact. Rec. Trav. Chim. Pays-Bas 1970, 89, 225–226.

    Article  Google Scholar 

  234. Williams, D.H.; Cooks, R.G.; Ronayne, J.; Tarn, S.W. Studies in Mass Spectrometry. XXVII. The Decomposition of Furan, Thiophene, and Deuterated Analogs Under Electron Impact. Tetrahedron Lett. 1968, 14, 1777–1780.

    Article  Google Scholar 

  235. Riepe, W.; Zander, M. The Mass Spectrometric Fragmentation Behavior of Thiophene Benzologs. Org. Mass Spectrom. 1979, 14, 455–456.

    Article  CAS  Google Scholar 

  236. Rothwell, A.P.; Wood, K.V.; Gupta, A.K.; Prasad, J.V.N.V. Mass Spectra of Some 2-and 3-Cycloalkenylfurans and -Cycloalkenylthiophenes and Their Oxy Derivatives. Org. Mass Spectrom. 1987, 22, 790–795.

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Institute of Organic Chemistry, University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany

    Dr. Jürgen H. Gross

Authors
  1. Dr. Jürgen H. Gross
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

Copyright information

© 2004 Springer-Verlag Berlin Heidelberg

About this chapter

Cite this chapter

Gross, J.H. (2004). Fragmentation of Organic Ions and Interpretation of EI Mass Spectra. In: Mass Spectrometry. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-36756-X_6

Download citation

  • DOI: https://doi.org/10.1007/3-540-36756-X_6

  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-642-07388-5

  • Online ISBN: 978-3-540-36756-7

  • eBook Packages: Springer Book Archive

Publish with us

Policies and ethics

Search

Navigation