Unimolecular Chemistry of Protonated Glycine and Its Neutralized Form in the Gas Phase

Sarka Beranova, Jinnan Cai, Chrys Wesdemiotis

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

Protonated glycine is produced in the gas phase by fast atom bombardment or chemical ionization (with CH5+), and its structures and unimolecular reactions are investigated by a combination of tandem mass spectrometry methods, including metastable ion (MI) characteristics, collisionally activated dissociation (CAD), and neutralization-reionization mass spectrometry (NRMS). The major fragmentations of [H2NCH2COOH]H+ are elimination of CO to form the ion–molecule complex H2O···+H2N=CH2 and consecutive cleavages of H2O + CO to yield the immonium ion +H2N=CH2. Other important reactions involve the losses of H*, H* + H2O, H2N*, H2N + H2O, *COOH, and CH5N. Due to the facile H+ migration possible in [H2NCH2COOH]H+, the precise site of protonation cannot unequivocally be pinpointed based on the unimolecular reactions of this ion. More definitive information is obtained from the chemistry of neutralized [H2NCH2COOH]H+. Analysis of this neutral by NRMS reveals that it consists of *H3NCH2COOH and H2NCH2C*(OH)2 at the moment of neutralization. Thus, the original protonation process must have created both tautomers. Once formed, the hypervalent ammonium radical *H3NCH2COOH (neutral counterpart of N-protonated glycine) dissociates completely to H* + H2NCH2COOH and H3NCH2 (or H2NCH3) + *COOH. On the other hand, the dihydroxy alkyl radical H2NCH2C*(OH)2 (neutral counterpart of O-protonated glycine) undergoes several distinctive fragmentations, e.g., to H2N* + C2H4O2 and H2NCH2* + CO + H2O.

Original languageEnglish (US)
Pages (from-to)9492-9501
Number of pages10
JournalJournal of the American Chemical Society
Volume117
Issue number37
DOIs
StatePublished - Jan 1 1995
Externally publishedYes

Fingerprint

Carbon Monoxide
Glycine
Mass spectrometry
Amino acids
Gases
Protonation
Ions
Mass Spectrometry
Tandem Mass Spectrometry
Ammonium Compounds
Ionization
Atoms

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this

Unimolecular Chemistry of Protonated Glycine and Its Neutralized Form in the Gas Phase. / Beranova, Sarka; Cai, Jinnan; Wesdemiotis, Chrys.

In: Journal of the American Chemical Society, Vol. 117, No. 37, 01.01.1995, p. 9492-9501.

Research output: Contribution to journalArticle

@article{48605a01fd054287bdf81338f621c907,
title = "Unimolecular Chemistry of Protonated Glycine and Its Neutralized Form in the Gas Phase",
abstract = "Protonated glycine is produced in the gas phase by fast atom bombardment or chemical ionization (with CH5+), and its structures and unimolecular reactions are investigated by a combination of tandem mass spectrometry methods, including metastable ion (MI) characteristics, collisionally activated dissociation (CAD), and neutralization-reionization mass spectrometry (NRMS). The major fragmentations of [H2NCH2COOH]H+ are elimination of CO to form the ion–molecule complex H2O···+H2N=CH2 and consecutive cleavages of H2O + CO to yield the immonium ion +H2N=CH2. Other important reactions involve the losses of H*, H* + H2O, H2N*, H2N• + H2O, *COOH, and CH5N. Due to the facile H+ migration possible in [H2NCH2COOH]H+, the precise site of protonation cannot unequivocally be pinpointed based on the unimolecular reactions of this ion. More definitive information is obtained from the chemistry of neutralized [H2NCH2COOH]H+. Analysis of this neutral by NRMS reveals that it consists of *H3NCH2COOH and H2NCH2C*(OH)2 at the moment of neutralization. Thus, the original protonation process must have created both tautomers. Once formed, the hypervalent ammonium radical *H3NCH2COOH (neutral counterpart of N-protonated glycine) dissociates completely to H* + H2NCH2COOH and H3NCH2 (or H2NCH3) + *COOH. On the other hand, the dihydroxy alkyl radical H2NCH2C*(OH)2 (neutral counterpart of O-protonated glycine) undergoes several distinctive fragmentations, e.g., to H2N* + C2H4O2 and H2NCH2* + CO + H2O.",
author = "Sarka Beranova and Jinnan Cai and Chrys Wesdemiotis",
year = "1995",
month = "1",
day = "1",
doi = "10.1021/ja00142a016",
language = "English (US)",
volume = "117",
pages = "9492--9501",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "37",

}

TY - JOUR

T1 - Unimolecular Chemistry of Protonated Glycine and Its Neutralized Form in the Gas Phase

AU - Beranova, Sarka

AU - Cai, Jinnan

AU - Wesdemiotis, Chrys

PY - 1995/1/1

Y1 - 1995/1/1

N2 - Protonated glycine is produced in the gas phase by fast atom bombardment or chemical ionization (with CH5+), and its structures and unimolecular reactions are investigated by a combination of tandem mass spectrometry methods, including metastable ion (MI) characteristics, collisionally activated dissociation (CAD), and neutralization-reionization mass spectrometry (NRMS). The major fragmentations of [H2NCH2COOH]H+ are elimination of CO to form the ion–molecule complex H2O···+H2N=CH2 and consecutive cleavages of H2O + CO to yield the immonium ion +H2N=CH2. Other important reactions involve the losses of H*, H* + H2O, H2N*, H2N• + H2O, *COOH, and CH5N. Due to the facile H+ migration possible in [H2NCH2COOH]H+, the precise site of protonation cannot unequivocally be pinpointed based on the unimolecular reactions of this ion. More definitive information is obtained from the chemistry of neutralized [H2NCH2COOH]H+. Analysis of this neutral by NRMS reveals that it consists of *H3NCH2COOH and H2NCH2C*(OH)2 at the moment of neutralization. Thus, the original protonation process must have created both tautomers. Once formed, the hypervalent ammonium radical *H3NCH2COOH (neutral counterpart of N-protonated glycine) dissociates completely to H* + H2NCH2COOH and H3NCH2 (or H2NCH3) + *COOH. On the other hand, the dihydroxy alkyl radical H2NCH2C*(OH)2 (neutral counterpart of O-protonated glycine) undergoes several distinctive fragmentations, e.g., to H2N* + C2H4O2 and H2NCH2* + CO + H2O.

AB - Protonated glycine is produced in the gas phase by fast atom bombardment or chemical ionization (with CH5+), and its structures and unimolecular reactions are investigated by a combination of tandem mass spectrometry methods, including metastable ion (MI) characteristics, collisionally activated dissociation (CAD), and neutralization-reionization mass spectrometry (NRMS). The major fragmentations of [H2NCH2COOH]H+ are elimination of CO to form the ion–molecule complex H2O···+H2N=CH2 and consecutive cleavages of H2O + CO to yield the immonium ion +H2N=CH2. Other important reactions involve the losses of H*, H* + H2O, H2N*, H2N• + H2O, *COOH, and CH5N. Due to the facile H+ migration possible in [H2NCH2COOH]H+, the precise site of protonation cannot unequivocally be pinpointed based on the unimolecular reactions of this ion. More definitive information is obtained from the chemistry of neutralized [H2NCH2COOH]H+. Analysis of this neutral by NRMS reveals that it consists of *H3NCH2COOH and H2NCH2C*(OH)2 at the moment of neutralization. Thus, the original protonation process must have created both tautomers. Once formed, the hypervalent ammonium radical *H3NCH2COOH (neutral counterpart of N-protonated glycine) dissociates completely to H* + H2NCH2COOH and H3NCH2 (or H2NCH3) + *COOH. On the other hand, the dihydroxy alkyl radical H2NCH2C*(OH)2 (neutral counterpart of O-protonated glycine) undergoes several distinctive fragmentations, e.g., to H2N* + C2H4O2 and H2NCH2* + CO + H2O.

UR - http://www.scopus.com/inward/record.url?scp=0001320086&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001320086&partnerID=8YFLogxK

U2 - 10.1021/ja00142a016

DO - 10.1021/ja00142a016

M3 - Article

VL - 117

SP - 9492

EP - 9501

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 37

ER -