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Volume 45 (1997)
- Issue 6 Pages 619-
- Issue 5 Pages 539-
- Issue 4 Pages 493-
- Issue 3 Pages 237-
- Issue 2 Pages 125-
- Issue 1 Pages 1-
Volume 45, Issue 4
Displaying 1-3 of 3 articles from this issue
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REGULAR PAPERS
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Masaharu TSUJI, Masato AIZAWA, Erika ODA, Yukio NISHIMURA1997 Volume 45 Issue 4 Pages 493-503
Published: 1997
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSIon-molecule reactions of CF3+ with propyne, allene, and 1-butyne have been studied at near-thermal energies (~0.05 eV) by using an ion-beam apparatus. Initial product ion distributions and reaction rate constants were determined. For propyne and allene, major product channels were electrophilic addition followed by HF and CF2 elimination and a minor product channel was a hydride abstraction reaction. For 1-butyne, major product channels were electrophilic addition followed by C2H2F2, C2H3F, and 2HF eliminations. The reaction rate constants were (1.5±0.1), (0.40±0.05), and (1.6±0.1)×10-9 cm3s-1 molecule-1 for propyne, allene, and 1-butyne, respectively.View full abstractDownload PDF (689K) -
Hiroshi KISHI, Toshihiro FUJII1997 Volume 45 Issue 4 Pages 505-519
Published: 1997
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSThis paper describes an experimental study on the influence of kinetic energy of fast monoterpene molecules on the surface ionization efficiency and on the mass spectral patterns, using rhenium oxide (ReO2) surface. Molecular kinetic energy, given to the molecules through the acceleration in the seeded supersonic molecular beam, ranged from 1 to 10 eV. Hyperthermal surface ionization mass spectra (HSIMS) were taken for various incident kinetic energies and surface temperatures. The observed mass spectra were interpreted in a purely empirical way, by means of evidence from the previous investigations, and they were compared with conventional EI techniques and with the thermal energy surface ionization technique (SIOMS; Surface Ionization Organic Mass Spectrometry). Ionization efficiency (β) was also studied.
Under hyperthermal surface ionization (HSI) conditions, many kinds of fragment ions, including quite abundant odd electron ions (OE+·) are observed. HSIMS patterns of monoterpenes are different among 6-isomers, contrary to those of SIOMS and EIMS, where very similar patterns for isomers are observed. HSIMS patterns are strongly dependent on the molecular kinetic energies. The surface temperature does not affect much the spectral patterns, but it controls the total amount of ion formation. We conclude from these mass spectral findings, HSI-mechanism contains an impulsive process of ion formation, followed by the fragmentation process as a results of the internal energies acquired through the collision processes.View full abstractDownload PDF (747K) -
Kazushige NISHIZAWA, Takahito MIKI, Ryuusuke IKEDA, Toshiyuki FUJII, T ...1997 Volume 45 Issue 4 Pages 521-527
Published: 1997
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSThe isotopic enriching process of the nickel isotopes by the liquid-liquid extraction using a crown ether of dicyclohexano-18-crown-6 was investigated. The nickel chloride exists simply as the aqua complex in the aqueous phase, not as the chloro complex even in the concentrated salt solution. The extraction reaction is supposed to be, Ni2+(6H2O)+L+2Cl-=NiLCl2+6H2O, where L represents the crown ether, and Ni2+(6H2O) and NiLCl2 denote the 6 hydrated nickel ion and the crown ether complex of nickel, respectively. The unit mass enrichment factor, εu=0.0017-0.0026 was small compared with that of zinc isotopes. The odd/even isotope effect was recognized to be as large as εO/E=0.018. The enrichment factor was reviewed at the correlation with the isotope shift of atomic spectra and the hyperfine structure splitting of 61Ni.View full abstractDownload PDF (526K)
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