Field ionization kinetic data processing by computer

Greef, J. van der; Pinkse, Frans A.; Kort, C. W. F.; Nibbering, Nico M. M.

doi:10.1016/0020-7381(77)80057-0

Cited by 23 publications

(3 citation statements)

References 7 publications

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“…13 The statement is not at odds with the observation of fast H / D randomization for decomposing C4H6 ions because, in this case, the competition is with a skeletal isomerization to give the 3-methylcyclopropene or similar intermediate rather than a direct cleavage reaction. Because the barrier height for ring opening is lower than for dissociation, and because both processes involve similar transition states, i.e., simple C-C bond cleavage, k-1 is less strongly affected than k2.…”

Section: Discussionmentioning

confidence: 99%

Decomposition of the 1,3-butadiene radical cation on the microsecond to picosecond time scale

Russell¹,

Gross²,

Greef³

et al. 1979

J. Am. Chem. Soc.

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1972). (17) N. M. M. Nibbering has informed us of a very slow reaction to eliminate CH40 for Ionized P-bvtene and methyl vinyl ether. We were unable to detect this reaction. Abstract:The decomposition of ionized 1,3-butadiene to give C3H3+ and .CH3 has been studied over the time interval of approximately 10-11-10-5 s using the complementary techniques of field ionization kinetics (FIK) and mass-analyzed ion kinetic energy spectroscopy (MIKES). By employing both carbon-1 3 and deuterium labeled 1,3-butadiene, it has been established that (1) hydrogen atom randomization takes place very rapidly and is complete by approximately lo-" s, (2) carbon atom randomization occurs at a slower rate which is competitive with the decomposition reaction. The hydrogen atom randomization is postulated to take place by isomerization to other acyclic C4H6 ions without change in the carbon skeleton. The near lack of carbon atom interchange at short times (10-9-10-11 s) is explained by invoking a high-energy formation of a methylcyclopropene which occurs as a rate-determining step. For more slowly decomposing (metastable) C4H6 ions, the ring-opening reaction of this intermediate to re-form the 1,3-butadiene cation becomes more competitive with dissociation, and this explains the nearly complete carbon atom randomization at longer times.

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Section: Discussionmentioning

confidence: 99%

Decomposition of the 1,3-butadiene radical cation on the microsecond to picosecond time scale

Russell¹,

Gross²,

Greef³

et al. 1979

J. Am. Chem. Soc.

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“…After having developed in‐house software to acquire and process field ionization kinetics data from the Varian MAT 711 double focusing mass spectrometer by computer (van der Greef et al, 1977) the first compound that was studied was 2‐phenoxyethyl chloride. Its molecular ion suffered from an equilibrated positional interchange of the phenoxy group and the halogen atom prior to decomposition as discussed in Section III.…”

Section: Field Ionization Kinetics and Field Desorption Mass Specmentioning

confidence: 99%

Four decades of joy in mass spectrometry

Nibbering

2006

Mass Spectrometry Reviews

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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.

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“…Typical conditions for both normal and MIKES geometry are ionizing energy 70 eV, emission 100 pA, ion accelerating voltage 3.7 kV (MIKES 5.5-6.5 kV) and p slit width on a Varian MAT 711 double focusing mass spectrorneter equipped with a combined EI/FI/FD source. 26 Ionization and appearance energies were determined using the sernilog m e t h~d . *~ Only the region of the ionization efficiency curve below 10% of the 30 eV ion current was used.…”

Section: The Chemistry Of Cho Radical Cations the Chemistry Of Chmentioning

confidence: 99%

The Chemistry of C₆H₆O radical cations: A study of rearrangement reactions of halogen substituted ethyl phenyl ethers

Russell

Gross

Greef

et al. 1979

Org. Mass Spectrom.

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New experimental data on the rearrangement reaction of various phenoxyethyl halides to give [c6&0] +. are presented and compared with previous studies so that a coherent picture of this process can be developed. By examining the metastable kinetic energy release for low energy decomposing molecnlar ions of the phenoxyethyl halides, it has been conduded that formation of [c6&0] occurs by competitive 1,2 and 1,3 hydrogen shifts from the aikyl carbons to oxygen followed by a rate determining C-O bond cleavage. This is substantiated by the absence of a pnmary hydrogen isotope effect. For more highiy activated molecular ions, a new mechanism comes into play as evidenced by the appearance of a small hydrogen isotope effect. It is postulated that this thud mechanism involves transfer of the akyl hydrogen to the ortho position of the ring by a rate determining 1,5 shift, followed by a 1,3 hydrogen shift from the ortho methylene group to oxygen and rapid C-O bond cieavage. This 1,3 hydrogen s h i to oxygen appears to be 'catalysed' by the haiogen atoms yieldmg phenol ions. No indications have been found for the formation of tautomeric 2,4-cyclohexadienone ions. Furthermore, more highiy activated moiedar ions produce [c6&0] +. which can undergo metastable decomposition to lose carbon monoxide. Kbetic energy release measurements for the latter reaction show that the majority of these [C,&O]+' ions have been formed as phenol ions as weU. These arguments are supported by energetic measurements and by comparisons with previous ion cyclotron resonance and collisional activation studies.

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Field ionization kinetic data processing by computer

Cited by 23 publications

References 7 publications

Decomposition of the 1,3-butadiene radical cation on the microsecond to picosecond time scale

Decomposition of the 1,3-butadiene radical cation on the microsecond to picosecond time scale

Four decades of joy in mass spectrometry

The Chemistry of C₆H₆O radical cations: A study of rearrangement reactions of halogen substituted ethyl phenyl ethers

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Field ionization kinetic data processing by computer

Cited by 23 publications

References 7 publications

Decomposition of the 1,3-butadiene radical cation on the microsecond to picosecond time scale

Decomposition of the 1,3-butadiene radical cation on the microsecond to picosecond time scale

Four decades of joy in mass spectrometry

The Chemistry of C6H6O radical cations: A study of rearrangement reactions of halogen substituted ethyl phenyl ethers

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The Chemistry of C₆H₆O radical cations: A study of rearrangement reactions of halogen substituted ethyl phenyl ethers