Unimolecular gas-phase reactions of methyl and ethyl trifluoroacetoacetates upon electron ionization

Tajima, Susumu; Watanabe, Daisuke; Ubukata, Makoto; Hiroi, Yuko; Nakajima, Satoshi; Nibbering, Nico M. M.

doi:10.1016/s1387-3806(02)00701-7

Cited by 7 publications

(5 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 (a) is clearly di#erent from that of the ions in the MIKE spectrum of the m/z 115 generated by the loss of CF 3 from the molecular ions of ethyl trifluoroacetoacetate. 22) In the latter MIKE spectrum, the most significant ion was observed at m/z 87 in contrast to that in Fig. 5(a).…”

Section: ῍1mentioning

confidence: 65%

“…5(a), in a similar manner as the fragmentation of the m/z 115 ions generated by the CF 3 loss from the molecular ions of ethyl trifluoroacetoacetate, CF 3 C(῍O) CH 2 C(῍O)῎ OCH 2 CH 3 . 22) However, the relative abundance of the ions is di#erent from each other, as described later. Fig.…”

Section: ῍1mentioning

confidence: 99%

“…5(a). It has been proposed 22) that a large part of the m/z 87 ions is generated from the enol form, S. Tajima et al…”

Section: ῍1mentioning

confidence: 99%

“…22) A large part of the m/z 115 ions from the latter is the enol form, because of the strong electronegativity of fluorine atom. 22) …”

Section: ῍1mentioning

confidence: 99%

See 3 more Smart Citations

Unimolecular Reactions of Diethyl Malonate Cation in Gas-phase

Tajima

Ishiguro

Mamada

et al. 2004

J. Mass Spectrom. Soc. Jpn.

Self Cite

View full text Add to dashboard Cite

Unimolecular reactions of diethyl malonate cation (CH3CH2OC(῎O)CH2C(῎O)OCH2CH3ῌῌ ; 1 ῌῌ , Mw : 160) induced by electron ionization, have been investigated by use of mass-analyzed ion kinetic energy (MIKE) spectrometry and D-labeling in conjunction with thermochemistry. In the metastable time window, the molecular ions ῌ ) ions decompose into the ions at m/z 115, 106, and 105 by the losses of H2O, C2H3, and C2H4, respectively. A large part of the first fragment ions would be in the keto form and it decomposes into the m/z 71 and 43 ions by the losses of CO2 and C3H4O2 (or C2O3), and a small part would be in the enol form and decomposes into the m/z 87 ions by the loss of C2H4, not CO. The m/z 43 ions are isobaric, C2H3Oῌ and C3H7 ῌ .

show abstract

Section: ῍1mentioning

confidence: 65%

Section: ῍1mentioning

confidence: 99%

See 2 more Smart Citations

Unimolecular Reactions of Diethyl Malonate Cation in Gas-phase

Tajima

Ishiguro

Mamada

et al. 2004

J. Mass Spectrom. Soc. Jpn.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In a study of ionized methyl and ethyl trifluoroacetates it was concluded that a large part of their metastably decomposing ions had the enol structure. Furthermore, their source generated and most abundant m / z 69 ions appeared to consist of both the trifluoromethyl cation and protonated carbon suboxide, the latter being formed by at least three and four different fragmentation routes from the methyl and ethyl esters, respectively (Tajima et al, 2002a). Heavily fluorinated diethyl ethers showed complex fragmentations upon electron ionization (Tajima et al, 2002b) while the metastable [ M methyl] + ions from 1,1,1‐trifluoroisopropyl methyl ether decomposed via the four competitive channels of carbon monoxide, methyl fluoride, difluorocarbene, and methoxyfluorocarbene elimination (Tajima et al, 2003a).…”

Section: Miscellaneousmentioning

confidence: 99%

Four decades of joy in mass spectrometry

Nibbering

2006

Mass Spectrometry Reviews

View full text Add to dashboard Cite

Tremendous developments in mass spectrometry have taken place in the last 40 years. This holds for both the science and the instrumental revolutions in this field. In chemistry the research was heavily focused on organic molecules that upon electron ionization fragmented via complex mechanistic pathways as shown by isotopic labeling experiments. These studies, including ion structure determinations, were performed with use of double focusing mass spectrometers of both conventional and reversed geometry, and equipped with various types of metastable ion scanning and collision-induced dissociation techniques developed by physical and analytical chemists. Time-resolved mass spectrometry by use of the field ionization kinetics method, developed by physical chemists, was another powerful way to unravel details of unimolecular gas phase ion dissociations. Then the development of new ionization methods, such as desorption chemical ionization, field desorption, and fast atom bombardment permitted not only to analyze unvolatile, thermally labile and higher molecular weight compounds, but also to study their chemical behavior in the gas phase, initially with use of double focusing instruments and later on with multisector and hybrid mass spectrometers. These ionization methods also enabled to study organometallic compounds and increasingly the field of medium-sized to large biomolecules, the latter being exploded in the last decade by the development of electrospray- and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry. Another area of research concerned the bimolecular chemistry of organic ions with organic molecules in the gas phase. Initially this was performed with use of among others drift-cell ion cyclotron resonance spectroscopy, that later on was replaced by the developed method of ion trapping and Fourier transform ion cyclotron resonance. Combination of the latter with the afore-mentioned ionization methods has shifted also in this case the research on organic molecules to organometallic/inorganic systems, and predominantly to biomolecules in the last decade. This invited review will describe the research efforts made by the author's group over the last 40 years together with some personal experiences during his career.

show abstract

Current Literature in Journal of Mass Spectrometry

2003

J. Mass Spectrom.

View full text Add to dashboard Cite

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (2 Weeks journals ‐ Search completed at 6th. Nov. 2002)

show abstract

Unimolecular gas-phase reactions of methyl and ethyl trifluoroacetoacetates upon electron ionization

Cited by 7 publications

References 12 publications

Unimolecular Reactions of Diethyl Malonate Cation in Gas-phase

Unimolecular Reactions of Diethyl Malonate Cation in Gas-phase

Four decades of joy in mass spectrometry

Current Literature in Journal of Mass Spectrometry

Contact Info

Product

Resources

About