Protonated molecule

IUPAC RECOMMENDATIONS 2013
Protonated molecule
Deprecated: protonated molecular ion, pseudo-molecular ion, quasi-molecular ion. Adduct ion, represented by [M + H]+, formed by the interaction of a molecule with a proton (hydron). Note 1: Multiply protonated molecules are represented by [M + nH]n+ where n is the number of protons. Note 2: Protonated molecular ion is deprecated; for example, for a molecular ion M+• this would correspond to a species carrying two positive charges plus an unpaired electron. Note 3: Pseudo-molecular ion and quasi-molecular ion are deprecated; a specific term such as protonated molecule, or a chemical description such as [M + H]+ should be used.
Related Term(s): adduct ion
Reference(s): IUPAC. Analytical Division. Compendium of Analytical Nomenclature (the Orange Book). Definitive Rules, 1979. Compiled by J. Inczédy, T. Lengyel, A. M. Ure. Blackwell Scientific Publications, Oxford (1997). On-line corrected version: http://www.iupac.org /publications/analytical compendium (2000). IUPAC. Compendium of Chemical Terminology, 2nd ed. (the Gold Book). Compiled by A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. M. Bursey. Mass Spectrom. Rev. 10, 1 (1991). (http://dx.doi.org/10.1002/mas.1280100102 )
From Definitions of Terms Relating to Mass Spectrometry (IUPAC Recommendations 2013); DOI: 10.1351/PAC-REC-06-04-06 © IUPAC 2013.
Index of Recommended Terms

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Orange Book

ORANGE BOOK DEFINITION IUPAC. Analytical Division. Compendium of Analytical Nomenclature (the Orange Book). Definitive Rules, 1979 (see also Orange Book 2023)
Protonated molecule
An ion formed by interaction of a molecule with a proton abstracted from an ion, as often happens in chemical ionization according to the reaction M + XH+ ? MH+ + X. The symbolism (M+H)+ may also be used. The widely used term 'protonated molecular ion' is not recommended as it suggests an association product of a proton with a molecular ion.
IUPAC 1997 Orange Book Chapter 12
Index of Orange Book Terms

Gold Book

GOLD BOOK DEFINITION IUPAC. Compendium of Chemical Terminology, 2nd ed. (the Gold Book). Compiled by A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997).
Protonated molecule
http://goldbook.iupac.org/P04908.html An ion formed by interaction of a molecule with a proton abstracted from an ion, as often occurs in chemical ionization according to the reaction: M + XH+ ? MH+ + X . The symbolism [M + H]+ may also be used to represent the protonated molecule. The widely used term 'protonated molecular ion' to describe the MH+ ion is not recommended, since it suggests an associated product of a proton with a molecular ion. Source: PAC, 1991, 63, 1541 (Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991)) on page 1550
IUPAC Gold Book
Index of Gold Book Terms

See also

• Molecular ion
• Cationized Molecule