bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative Studies of 2-, 3-, and 4-Pyridylpalladium(II) Complexes: Synthesis and Properties
Authors: Isobe Kiyoshi , Nakamura Yukio , Miwa Toshio , Kawaguchi Shinichi 
Published: July 2006

Abstract
Oxidative addition reactions of bromopyridines to tetrakis(triphenylphosphine)palladium(0) gave [{PdBr(2-pyridyl)(PPh3)2] (1b), trans-[PdBr(3-pyridyl)(PPh3)2] (2b), and trans-[PdBr(4-pyridyl)(PPh3)2] (3b), which were converted on treatment with triethylpnosphine to trans-[PdBr(2-, 3-, and 4-pyridyl)(PEt3)2] complexes (1d, 2d, 3d, respectively). Titration with perchloric acid in dioxane–water (1:1 by volume) indicated the basicity sequence of these complexes: 2-pyridyl&gt;&gt;4-pyridyl&gt;3-pyridyl. The bromide ligand in 1b–3b can readily be replaced by Cl−, I−, N3−, NCO−, and NCS−. In each corresponding series the relative thermal stability is in the sequence of 2-pyridyl&gt;4-pyridyl&gt;3-pyridyl. The pyridyl complexes containing triphenylphosphine react with carbon monoxide at ambient temperature and pressure to afford acyl complexes, which produce the corresponding esters by reactions with methanol. They also act as catalysts for cross coupling reactions of bromopyridines.
The Crystal and Molecular Structure of the Hydrated Light Lanthanoid(III) Chloroacetates, [{M(ClCH2CO2)3}3(H2O)5]n, (M=La, Pr, Nd, and Eu)
Authors: Imai Takashi , Shimoi Mamoru , Ouchi Akira 
Published: July 2006

Abstract
The crystal and molecular structures of the hydrated lanthanum(III), neodymium(III), and europium(III) chloroacetates indicated in the title were determined by the single-crystal X-ray diffraction method; these three salts as well as the praseodymium(III) salt are apparently isomorphous. By the same synthetic technique, gadolinium(III) or heavier lanthanoid(III) did not give the isomorphous salts. Their crystals are monoclinic with the space group of P21⁄c, and the cell constants of the neodymium(III) salt, for example, are, a=14.805(4), b=18.765(4), c=14.403(5) Å, β=95.13(3)°. There are crystallographically independent three kinds of nine-coordinated metal atoms: Nd(1), Nd(2), and Nd(3). Among them, Nd(1) and Nd(2) are best approximated as being in a tricapped trigonal prism geometry. The Nd(3) is best regarded as being in a monocapped square-antiprism geometry, although one more additional oxygen atom, O(35), approaches one side face. In the lanthanum(III) complex, O(35) is thought to be ligated to La(3), while in the europium(III) complex O(35) is perfectly removed from Eu(III), being accompanied by a change in the coordination geometry of the ligand. In the crystal, the metal atoms are bridged by carboxylato ligands, forming polymeric chains approximately along [−110] or [110] axis. There are no carboxylato bridges between respective chains, although there are some hydrogen-bondings linking them with each other.
The Crystal and Molecular Structure of Heavy Lanthanoid(III) Chloroacetates in the Hydrated Form, [M3ClCH2CO2)9(H2O)4]n·nH2O (M=Gd, Dy, Er, and Yb)
Authors: Sugita Yoshihiko , Ouchi Akira 
Published: July 2006

Abstract
The crystal and molecular structures of the chloroacetato complexes of gadolinium(III), erbium(III), and ytterbium(III) indicated in the title were determined by the single-crystal X-ray diffraction method. In addition to these three complexes, the isomorphous dysprosium(III) salt was also obtained. Their chemical composition, M3L9·5H2O (where M=Gd, Dy, Er, or Yb; HL=chloroacetic acid), is the same as that of the light lanthanoid(III) (La–Eu) chloroacetates, though the latter crystals are monoclinic. The cell constants of the ytterbium(III) salt, for example, are: triclinic, space group P\bar1, a=13.278(10), b=13.624(6), c=12.067(4) Å α=96.62(3), β=100.68(5), γ=67.40(4)°, Z=2 (including 6 metal atoms). There are three kinds of crystallographically independent metal atoms; Yb(1), Yb(2), and Yb(3): Yb(1) and Yb(2) are octa-coordinated (square-antiprism geometry) and Yb(3) is ennea-coordinated (monocapped square-antiprism geometry). Two oxygen atoms around the last type of the metal atom are the more separated in the higher atomic-number lanthanoid(III) complex, while the other M–O bond lengths decrease, depending on the increase of the metal atomic number. The metal atoms are bridged by carboxylate ions in a chair form along the [111] axis, though in a way different from that of the light lanthanoid(III) complexes.
ESR Studies of the Dynamic Properties of Ion Radicals Captured by Surfactant Micelles
Authors: Suga Kosaku , Maemura Koushi , Fujihira Masamichi , Aoyagui Shigeru 
Published: July 2006

Abstract
ESR spectra of duroquinone anion radical (DQ−), methyl viologen cation radical (MV+), and 5,10-dimethyl-5,10-dihydrophenazine cation radical (DMPZ+) were measured in various aqueous surfactant solutions. The line width of each peak of the ESR spectra for DQ− in cationic and anionic surfactant solutions showed a quadratic dependence on the total nuclear quantum number, M=Σmi (i=1 to 12), of methyl protons of DQ−. The rotational correlation times, τc, of DQ− determined from these dependences, were 10−9–10−8 s in cationic surfactant (dodecyl-, tetradecyl-, and hexadecyltrimethylammonium bromide) solutions, and 10−10–10−9 s in nonionic surfactant (Triton X-100) solution. ESR spectra of MV+ and DMPZ+ in anionic surfactant (sodium dodecyl sulfate; SDS) solution showed anomalous patterns as not exhibiting the hyperfine splittings due to the nitrogen nucleus. These anomalies were explained by the more significant broadening of the outer peaks due to nitrogen splitting compared with the broadening of the central peaks corresponding to the nuclear quantum number of nitrogen, MN=mN1+mN2=0. From these results, the rotational correlation time for DMPZ+ in SDS solution was estimated as about 10−10 s.
Reactivities of Stable Rotamers. XVIII. Reactions of 9-[2-(1-Hydroxyethyl)-1-naphthyl]fluorene Rotamers with Sulfuric Acid and Thionyl Chloride
Authors: Oki Michinori , Tsukahara Jiro , Moriyama Kazuhiro , Nakamura Nobuo 
Published: July 2006

Abstract
Treatment of the title compound with 70% sulfuric acid in 1,2-dimethoxyethane caused cyclization for the ap isomer, whereas it did dehydration to produce a vinyl compound smoothly for the sp. The same treatment with 10% sulfuric acid in 1,2-dimethoxyethane afforded the corresponding vinyl compounds from both rotamers. Treatment of the alcohol with thionyl chloride afforded the corresponding chloride in the case of the sp-alcohol, while it gave the sp-vinyl compound in addition to the ap-chloride in the case of the ap-alcohol. The change in solvents in the reaction of the ap form caused the change in the ratio of the olefin vs. the chloride: The polar solvents enhance the rates of formation of the chloride. Introduction of three deuteriums to the methyl group of the ap-form of the title compound suppressed the formation of the olefin to some extent. The results are explained on the grounds of steric effects in the ion-pair formation from the chlorosulfites and the contribution of the C–H stretching in the transition state of the elimination.
Spectroelectrochemical Determination of Redox Potential of Cytochrome c′ in Rhodospirillum rubrum Chromatophores
Authors: Erabi Tatsuo , Yamashita Yoshiharu , Nishimura Kumiko , Wada Masanori 
Published: July 2006

Abstract
A spectroelectrochemical technique has been used for redox study of cytochrome c′ in chromatophores in the presence of Toluidine Blue O as a mediator. The midpoint potential of cytochrome c′ thus determined was 0 mV (n=1) at pH 7.0, which agreed well with the value determined by redox titration.
Enantioselective Ion-Association Mode between the Tris(ethylenediamine)cobalt(III) Cation and the Bis(μ-(−)589-2,3-dimethyltartrato)diantimonate(III) Anion in Solution
Authors: Yoneda Hayami , Sakaguchi Ushio , Nakazawa Hiroshi 
Published: July 2006

Abstract
By analyzing the intensity changes in the circular dichroism spectra, the association constants of the Λ-and Δ-[Co(en)3]3+ ions with the bis(μ-(−)589-2,3-dimethyltartrato)diantimonate(III) ion were determined to be 58.4±1.9 and 38.6±0.4 respectively in H2O (mol−1 dm3 at 25°C and μ=0.1 (NaClO4)). Based on these data together with the chromatographic data, the enantioselective association mode was discussed.
Concurrent Anodic Cyanation and Methoxylation of Methylated Furans. Oxidation Potential and Reactivity, and Stereochemical Control of Addition
Authors: Yoshida Kunihisa , Fueno Takayuki 
Published: July 2006

Abstract
The potentiostatic electrooxidation of a series of methyl-substituted furans was performed in MeOH that contains NaCN at a Pt anode in a divided cell. In all instances, the 1,4-additions of cyano and/or methoxyl group(s) across the furan ring were achieved. Replacement of an aromatic hydrogen by a cyano group occurred concurrently in some cases. The relative rates of cation radicals toward two different nucleophiles (CN− ion and the solvent MeOH (or the MeO− ion as a result of the equilibrium between CN− ion and the solvent MeOH)) at the electrode surface were determined from the yields of products by using the rate expressions of competitive reactions. There is a linear correlation between the relative reactivity of the furans (on a log scale) and their oxidation potential. The ratio of stereoisomers formed in an electrooxidation of 2,5-dimethylfuran (2,5-DMF) changes with addition of adsorbable compound as well as substrate concentration and this is thought to be due to the influence of concentration (or coadsorbate) on substrate orientation in the adsorption layer.
Evidence for the Similarity Recognition Hypothesis. Structure Dependence of the Selectivity in Oxidation of a Pair of Associating Thiols Each Having an Alkyl Group
Authors: Endo Tadashi , Ueda Takeshi , Isago Takashi , Kato Jun-ichi , Suzuki Takashi , Misaka Makoto , Ito Masato M 
Published: July 2006

Abstract
In base-catalyzed oxidation of a pair of associating thiols [HSCH2–CONHCONH–R1 and HSCH2CH2–NHCONHCO–R2] (R1=n-C4H9, R2=n-CnH2n+1) with oxygen, the selectivity (a measure of molecular recognition) at 35.0°C reached a maximum for R1=R2 (=n-C4H9) both in aqueous acetonitrile (n=2 to 6) and in aqueous ethanol (n=3 to 5).
Optical Resolution and Absolute Configuration of Axially Dissymmetric 2,2′-Dihydroxy-6,6′-dimethylbiphenyl
Authors: Kanoh Shigeyoshi , Tamura Nobuyuki , Motoi Masatoshi , Suda Hiroshi 
Published: July 2006

Abstract
2,2′-Dihydroxy-6,6′-dimethylbiphenyl (1) was successfully resolved into its optically pure forms by the recrystallization of the diastereomeric salts derived from the hydrogenphosphate of 1 and cinchonidine or quinine. The dextrorotatory 1 was determined to have R-configuration.
Synthesis of Liquid Hydrocarbons from Carbon Monoxide and Water with a Hybrid Catalyst
Authors: Tominaga Hiro-o , Miyauchi Michiharu , Fujimoto Kaoru 
Published: July 2006

Abstract
Liquid hydrocarbons were produced from carbon monoxide and water at temperatures from 220 to 280°C and under moderately pressurized conditions (3 atm), by utilizing a hybrid catalyst composed of a Co/SiO2 catalyst and a CO shift conversion catalyst. Most of the steam, either added or formed, was converted to hydrogen in the reaction of H2O with CO on the CO shift catalyst.
Thermodynamic Study on Solvent Extraction of 18-Crown-6–Alkali Metal Ion Complexes and Tetraalkylammonium Ions with Picrate Anions into Benzene
Authors: Takeda Yasuyuki , Matsumoto Yoshiki 
Published: July 2006

Abstract
Enthalpy and entropy changes for ion-pair extractions of tetraalkylammonium ions (Me4N+, Et4N+, n-Pr4N+, n-Bu4N+) with picrate anions, overall extractions of alkali metal (Na, K, Rb, Cs) picrates with 18-crown-6 (18C6), and distribution of 18C6 itself were determined between benzene and water, Me, Et, n-Pr, and n-Bu denoting methyl, ethyl, propyl, and butyl groups, respectively. All the extracted 18C6 complexes were 1:1:1 complexes (alkali metal ion: 18C6: picrate anion). The values of enthalpy and entropy changes are negative for overall extractions of all the alkali metal picrates with 18C6. Plots of thermodynamic quantities for ion-pair extractions of R4NA vs. the number of carbon atoms of R4N+ show a linear relationship, R4N+ and A− being tetraalkylammonium ion and picrate anion, respectively. Enthalpy and entropy changes were calculated for ion-pair extractions of 18C6–alkali metal ion complexes with picrate anions. The thermodynamic parameters for ion-pair extractions of 18C6–alkali metal picrate complexes were compared with those of R4NA, and were discussed in detail from the standpoint of molecular grounds. It was found from these data that the 18C6–K+ complex acts as a structure breaker in water.
Action of Electron-Accepting Quenchers in Photoisomerization of Naphthylethylenes in Polar and Nonpolar Solvents
Authors: Oguchi Takahisa , Arai Tatsuo , Sakuragi Hirochika , Tokumaru Katsumi 
Published: July 2006

Abstract
The quantum yield of trans-cis isomerization of 3,3-dimethyl-1-(2-naphthyl)-1-butene was measured in the presence of various electron-accepting quenchers in benzene or in acetonitrile. In benzene the quantum yield was increased by addition of some of the quenchers; however, in acetonitrile it was decreased under similar conditions. This was attributed to more efficient formation of olefin triplets through an exciplex in benzene than through radical ion pairs in acetonitrile.
NAD(P)+–NAD(P)H Model. 63. Regioselective Reduction of Dienoic Ketones and Aldehydes with an NAD(P)H Model on Silica Gel
Authors: Fujii Masayuki , Nakamura Kaoru , Yasui Shinro , Oka Shinzaburo , Ohno Atsuyoshi 
Published: July 2006

Abstract
The Hantzsch ester reduces carbon–carbon double bonds in α,β-unsaturated ketones and aldehydes under the catalysis of silica gel. The 1,4-selectivity is satisfactorily high even in the reductions of polyenes conjugated to a carbonyl group. Methyl substituent at an olefinic position (α or β to the carbonyl group) retards the reduction. The reduction can be used as a useful tool in obtaining building blocks for the syntheses of terpenoids and their derivatives.
Synthesis of Some Five- and Six-Membered Oxasteroids of Cholestane Series by Ring Contraction and the Mass Spectrometric Fragmentations of Oxasteroids
Authors: Suginome Hiroshi , Yamada Shinji 
Published: July 2006

Abstract
Synthesis of several new five- and six-membered oxasteroids of the cholestane series by the ring contraction of those oxasteroids whose oxygen-containing ring is larger by one member has been achieved. Ring contraction utilizes a series of reactions recently developed by us for the transformation of cyclic ketones into cyclic ethers; it involves a regioselective β-scission of the alkoxyl radical generated by irradiation of the lactol hypoiodite derived from the starting oxasteroid to give the iodoformate followed by its cyclization. The present work demonstrates the versatility of our new method for the synthesis of cyclic ethers and extends the scope of its application. The mass spectral fragmentation of some oxasteroids synthesized in the present and previous work is discussed.
Reinvestigation of Base-Catalyzed Condensation of Ethyl α,α-Dichloroacetoacetate with Aldehydes. A New Synthesis of (±)-Disparlure
Authors: Tsuboi Sadao , Furutani Hiroyuki , Takeda Akira , Kawazoe Kayoko , Sato Sadao 
Published: July 2006

Abstract
The titled reaction gave ethyl 2-chloro-2,3-epoxyalkanoates (2) and ethyl 3-chloro-2-oxoalkanoates in improved yields. The structure of the by-product was revised as 1,5-dichloro-4,8-dialkyltricyclo[5.1.0.03,5]octane-2,6-dione by means of the 13C–1H two-dimensional NMR spectrum and an X-ray crystallographic analysis. Compound 2 was applied to the synthesis of (±)-disparlure, the pheromone of the gypsy moth, in 49% overall yield via 6 steps.
Asymmetric Catalytic Hydrogenations of N-Pyruvoyl-(S)-proline Esters
Authors: Munegumi Toratane , Fujita Manabu , Maruyama Tetsuya , Shiono Shozo , Takasaki Michiaki , Harada Kaoru 
Published: July 2006

Abstract
Asymmetric catalytic hydrogenations of the entitled compounds were carried out over palladium on charcoal in various solvents to afford N-[(S)-lactoyl]-(S)-proline esters with a d.e.(=diastereoisomeric excess) of up to 59%. The stereochemistry of the catalytic hydrogenation was explained by the “chelation mechanism.” And the effects of temperature and bulkiness of the ester groups on the asymmetric induction were also described.
Partial Specific Compressibility and Its Relation to Solvation of Solute Based on Measurements of Suspension System
Authors: Nomura Hiroyasu , Kawaizumi Fumio , Iida Takeshi 
Published: July 2006

Abstract
The relation between limiting partial specific compressibility, \barκ20, and solvation of solute was reviewed and determination of \barκ20 was carried out in different types of solutions; ideal binary mixtures, such as benzene–toluene, and suspension systems of polystyrene latex and colloidal silica. In ideal mixture and polystyrene latex systems, the partial specific compressibility and limiting partial specific volume of each solute were equal to the corresponding value of the solute itself. The \barκ20 of the colloidal silica decreased from a positive to negative value with increasing pH of the media, showing strong hydration in alkaline solution.
Selective Formation of Formic Acid, Oxalic Acid, and Carbon Monoxide by Electrochemical Reduction of Carbon Dioxide
Authors: Ikeda Shoichiro , Takagi Takehiko , Ito Kaname 
Published: July 2006

Abstract
Selective formation of formic acid, oxalic acid, and carbon monoxide by electrochemical reduction of carbon dioxide (CO2) is demonstrated using several metallic electrodes in aqueous and nonaqueous electrolytes. The electrode metals catalyze the electrochemical reduction of CO2 and are classified to three groups according to their main products from CO2. In and Pb electrodes as well as Hg electrodes are useful for the selective formation of formic acid by electrochemical reduction of CO2 in aqueous electrolytes. In the case of nonaqueous electrolytes, Pb, Hg, and Tl are useful for oxalic acid, and In, Zn, Au, and Sn electrodes are useful for carbon monoxide. Also, reaction mechanisms of CO2 electrochemical reduction are discussed.
Stereochemical Properties of Copper(II) Complexes of (RS)-3-Aminohexahydroazepine: Crystal and Molecular Structures of [(R)-3-Aminohexahydroazepine][(S)-3-aminohexahydroazepine]copper(II) Diperchlorate, [Cu(R-ahaz)(S-ahaz)](ClO4)2 and Related Complexes
Authors: Saburi Masahiko , Miyamura Kazuo , Morita Masatoshi , Yoshikawa Sadao , Tsuboyama Sei , Sakurai Tosio , Yamazaki Hiroshi , Tsuboyama Kaoru 
Published: July 2006

Abstract
Orange-red copper(II) complexes of (RS)-3-aminohexahydroazepine (=RS-ahaz), Cu(RS-ahaz)2X2·nH2O (X−=ClO4−, BF4−, NO3−, Br−, I−) were prepared, and the molecular structures of complex 1 (X−=ClO4−; n=0) and complex 2 (X−=Br−; n=2) were determined by the single-crystal X-ray diffraction method. The complex 1 has centrosymmetry, and the complex cation in 1 involves a pair of R- and S-ahaz (R- and S-ahaz refer to (R)-and (S)-3-aminohexahydroazepine) and takes a strict four-coordination geometry, so that 1 is formulated as [Cu(R-ahaz)(S-ahaz)](ClO4)2. The complex cation in 2 resembles closely that of 1, and 2 can be represented as [Cu(R-ahaz)(S-ahaz)]Br2·2H2O. The other orange-red complexes of RS-ahaz (X−=BF4−, NO3−, I−) were concluded to take similar strict four-coordinated structures. Blue-violet hetero-anion complexes Cu(RS-ahaz)2X(ClO4) were obtained from complex 1 and LiX (X−=Cl−, Br−). The crystal structure determination of Cu(RS-ahaz)2Br(ClO4) (=complex 3) revealed that 3 involves a pair of enantiomeric five-coordinated cations, [CuBr(R-ahaz)2]+ and [CuBr(S-ahaz)2]+, in the single crystal, whereby the ligand exchange which proceeds during the transformation from 1 to 3 is indicated.
Activation Parameters of Bromoacetate–Thiosulfate Reaction in Ethylene Glycol–Water Mixtures
Authors: Biswas Prasanta Kumar , Maula Anwarul , Das Mihir Nath 
Published: July 2006

Abstract
The activation parameters for the reaction between bromoacetate (\barR) and S2O32− ions in water and aqueous mixtures of ethylene glycol (5–50% by weight) have been evaluated from the rate constants, corresponding to zero ionic strength, at 15, 25, and 35 °C. The standard free energies of transfer (ΔGtr°) of the reacting ions and hence of the transition state (ΔGtr#) from water to the mixed media at 25 °C have been determined from the measured solubilities of AgR, TlCl, and Tl2S2O3 in the different media, using the reported values of ΔGtr° of Ag+ and Cl− ions. Attempts have been made to interpret the kinetic results in the light of solvent properties and free energies of transfer. Although both the reacting ions are destabilized, on adding glycol to the medium, the larger destabilization of the transition state, arising from decreased dielectric constant as well as solvating capacity of the medium, outweighs the combined effects on the reactants leading to reduced reaction rates.
Electrochemical Preparation of Tetrakis(isocyanide)dipalladium(I) Dichloride
Authors: Yamamoto Yasuhiro , Takahashi Katsuo , Yamazaki Hiroshi 
Published: July 2006

Abstract
The electrochemical behavior of PdCl2(RNC)2 (1) has been investigated in acetonitrile at Pt and Hg electrodes. The cyclic voltammogram of 1 showed a reduction wave at ca. −1.2 V, corresponding to a two-electron transfer. Coulometric reduction of 1 at the Pt electrode gave a binuclear complex, Pd2Cl2(RNC)4 (2). A similar reaction at the Hg electrode gave 2 in a relatively low yield. A Pt electrode was superior to a Hg one in the electrochemical synthesis of 2. The polarogram of 1 at a Hg electrode suggested a CE mechanism of the electrode reaction.
Evaluation of the Hydrogen Shuttling Ability of Coal Liquefaction Solvents
Authors: Chiba Koji , Tagaya Hideyuki , Suzuki Tohru , Suzuki Takashi 
Published: July 2006

Abstract
The hydrogen-shuttling ability of coal liquefaction solvents were evaluated using benzophenone and dibenzyl ether as hydrogen acceptors. Hydrogen-transfer reactions from tetralin to acceptors were accelerated by shuttiers and the ranking of the shuttling ability was determined to be as follows: anthracene&gt;fluorene&gt;pyrene≅triphenylmethane&gt;phenanthrene&gt;1-methylnaphthalene
A Light-Scattering Study of Temperature Effect on Micelle Formation of N-Alkanoyl-N-methylglucamines in Aqueous Solution
Authors: Okawauchi Makoto , Hagio Mayumi , Ikawa Yoshitomi , Sugihara Gohsuke , Murata Yoshio , Tanaka Mitsuru 
Published: July 2006

Abstract
The physicochemical properties of N-alkanoyl-N-methylglucamine in aqueous solution have been studied by applying a Debye plot and small-system thermodynamics to an analysis of static light scattering data in the temperature range from 25 to 55 °C. A small minimum was found in a plot of the critical micelle concentration vs. temperature, instead of the monotonously decreasing tendency, as in the case of poly(oxyethylene) alkyl ether. The temperature dependence of the aggregation number of the micelle and the spread of the aggregation number distribution of micelle are both very small. The standard enthalpy change associated with micelle formation varies from positive to negative as the temperature is raised. The micellization of N-alkanoyl-N-methylglucamine surfactants is discussed separately in terms of the respective contributions from the hydrophilic and hydrophobic groups.
Time-Resolved Unimolecular Fragmentations of C3H7O+ Ions
Authors: Arakawa Ryuichi , Yoshikawa Yozaburo 
Published: July 2006

Abstract
The unimolecular dissociations of the C3H7O+ ions produced by the dissociative ionization of t-butyl and s-butyl alcohols have been studied by means of trapped ion mass spectrometry(TIMS). The metastable peak intensities for two competing formations of C3H5+ and CH3O+ have been measured for the ion lifetimes of 0–50 μs. Also, the shifts of the electron-ionization-efficiency(EIE) curves for these ions have been observed between the ion-storage times of 2 and 800 μs. These data have then been fitted by means of QET model calculations. The dissociation paths of C3H7O+ can be interpreted without any assumption of a ratedetermining isomerization process.