bluuebunny/crossref_metadata_2025_split huggingface dataset:
Products from the Nitration of 2,5-Dimethylthiophene and Its 3,4-Dibromo Derivative. Two Modes of the Formation of Dithienylmethanes
Authors: Suzuki Hitomi , Hidaka Ichiro , Iwasa Akemi , Mishina Tadashi , Osuka Atsuhiro 
Published: July 2006

Abstract
The reaction of 2,5-dimethylthiophene with copper(II) nitrate in acetic anhydride gave 3-nitro-2,5-dimethyl-thiophene and 2,5-dimethyl-3-(5-methyl-2-thenyl)thiophene as major isolable products. The treatment of 3,4-dibromo-2,5-dimethylthiophene with nitric acid (d=1.5) in dichloromethane in the presence of a catalytic amount of sulfuric acid afforded 3,4-dibromo-5-methyl-2-(nitrooxymethyl)thiophene, which, on thin-layer chromatog-raphy over silica gel using hexane as the eluant, underwent a partial novel coupling reaction through the loss of one methylene carbon atom, thus giving 3,3′,4,4′-tetrabromo-5,5′-dimethyldi-2-thienylmethane along with the expected 3,4-dibromo-2-hydroxymethyl-5-methylthiophene and bis(3,4-dibromo-5-methyl-2-thenyl) ether.
Silylation of Relatively Acidic Compounds with Alkyl Trimethylsilylacetates
Authors: Nakamura Eiichi , Hashimoto Koichi , Kuwajima Isao 
Published: July 2006

Abstract
Silylation of ketones, alcohols, alkanethiols, phenols, and carboxylic acids with alkyl trimethylsilylacetates has been described from synthetic and mechanistic points of view.
The Electronic Structures of Condensed Materials Studied by Ultraviolet Photoelectron Spectroscopy
Authors: Takahashi Takashi , Harada Yoshiya 
Published: July 2006

Abstract
The so lid phase ultraviolet photoelectron spectra of water, carbon disulfide, benzene, N-methylaniline, and pentane condensed on a gold substrate at 77 K were measured. The features of the spectra are similar to those of the corresponding gas phase spectra. The difference between the gas and solid phase IP’s, the relaxation shift, is nearly constant for each compound studied except for the case of water, where the 3a1 molecular orbital state in solid is affected by the hydrogen bonding. The values of the relaxation shift for water, benzene and carbon disulfide are 1.1–1.3eV, while those for N-methylaniline and pentane are 0.6 and 0.7 eV, respectively. The small values for the latter compounds are due to the fact that the molecules are loosely packed in the solids. The mechanisms of the band broadening for the molecular crystal are discussed in relation to the spectrum of solid carbon disulfide. For N-methylaniline the spectra of the gas, liquid and solid phases were compared. To our knowledge, this is the first case in which the electronic structures of all the three phases are studied by ultraviolet photoelectron spectroscopy.
Halogenation with N-Halo-2-oxazolidinones. The Chain-carrying N-Centered Radicals
Authors: Migita Toshihiko , Nakayama Mitsumasa , Watanuki Toshiro , Suzuki Mikio , Kosugi Masanori 
Published: July 2006

Abstract
Selectivities in halogenation of 2,3-dimethylbutane, 1-chlorobutane and substituted toluenes with N-chloro-or N-bromo derivatives of 4,4-dimethyl-2-oxazolidinone (NXDMO), 2-oxazolidinone (NXO), and succinimide (NXS) were examined. In the presence of olefin, halogenation of the substituted butane by these N-halo reagents were found to proceed involving hydrogen abstraction by the N-centered radicals, since chlorination by the N-chloro reagents and bromination by the corresponding N-bromo reagents showed the same selectivities. The relative reactivity of a t-C-H bond compared with a prim-C-H bond RSpt markedly depends on the structure of the N-radical, being 200, 70, and 11 at 80 °C toward the radicals derived from NXDMO, NXO, and NXS, respectively. Reaction constant ρ of hydrogen abstraction from the toluenes by the N-radical from NXDMO was −1.0 at 130 °C.
The σ-Bonded Palladium(II) Complex of [π-(Dimethylaminomethyl)-cyclopentadienyl]tetraphenylcyclobutadienecobalt(I)
Authors: Izumi Taeko , Maemura Mitsugi , Endoh Kazuyoshi , Oikawa Tadashi , Zakozi Satoshi , Kasahara Akira 
Published: July 2006

Abstract
[π-(Dimethylaminomethyl)cyclopentadienyl]tetraphenylcyclobutadienecobalt(I) reacts with lithium tetrachloropalladate(II) in the presence of sodium acetate to give an ortho-palladated binuclear complex. The σ-bonded structure of the complex was confirmed by studies of the IR and 1H-NMR spectra and of the reactions with triphenylphosphine, thallium(I) acetylacetonate, and lithium aluminum deuteride. The reactions of the σ-bonded complex with carbon monoxide and olefins have been examined.
“Naked” Hydrogencarbonate Ion as a Bifunctional Catalyst toward Amide Substrates. Nucleophilic Ion Pairs. 9
Authors: Shinkai Seiji , Nakashima Naotoshi , Kunitake Toyoki 
Published: July 2006

Abstract
The cleavage of amide substrates (p-nitro-N-methyltrifiuoroacetanilide and p-nitro-N-methyldichloroacetanilide) with anionic nucleophiles was studied at 30 °C in aprotic (acetonitrile and N,N-dimethylformamide) and protic(ethanol) media. Hydrogencarbonate ion acted as catalyst much more efficiently in the aprotic solvents (about 103 fold) than expected from its aqueous pKa, but in ethanol, its reactivity was close to those of simple nucleophiles (p-cyanophenolate anion and N-hydroxysuccinimide anion) that possess analogous pKa values in water. The reaction rate in the aprotic solvents was sensitive to small amounts of water. The kinetic isotope effect showed that proton transfer was involved (at least partially) in the rate-determining step. Thus, hydrogencarbonate ion behaves in aprotic media as a nucleophilic-general acid catalyst for the amide cleavage. The biochemical implication with regard to the action of biotin was discussed.
Study of Phase Transfer Catalysis by Layered Scintillation Method
Authors: Hideshima Taketoshi , Morinaga Misao , Kimizuka Hideo 
Published: July 2006

Abstract
The static and kinetic feature of the reaction of sodium cyanide with 1-bromoalkanes in the presence of various phase transfer catalysts was investigated in the oil/water system by using a layered scintillation method and the mechanism of catalytic action was discussed. From the measurement of equilibrium constants for both reactions of hexadecyltrimethylammonium cyanide with 1-bromooctane and of sodium cyanide with hexadecyltrimethylammonium bromide in organic phase, it was pointed out that the latter reaction was responsible for the advance of overall reaction. It was also found that majority of the phase transfer catalysts exist in the oil phase. It was suggested that an uptake reaction of cyanide ion from the aqueous phase at the interface is essential and that the reaction process does not follow a simple model proposed by Starks et al.
The Crystal and Molecular Structures of Paracyclophadiynes
Authors: Ueda Hideo , Katayama Chuji , Tanaka Jiro 
Published: July 2006

Abstract
The molecular structures of tetramethyl[3.3]paracyclophadine(I) and [3.4]paracyclophadiyne(II) have been determined by X-ray analysis. Both crystals are monoclinic, with the space group of P21/c. The crystal data are: a=9.170(4), b=9.208(3), c=18.232(7) Å, β=94.0(1)°, Z=4 for (I) and a=10.938(3), b=9.173(2), c=14.988(4) Å, β=116.1(1)°, Z=4 for (II). In both molecules, consisting of benzene and diacetylene groups linked by two methylene-bridges, the diacetylene chain is bent into a bow shape. The (I) molecule has Cs symmetry, and the distances (3.019–3.256 Å) between the atoms of the diacetylene group and the benzene plane are smaller than those of [3.3]paracyclophadiyne(Aono, Sakabe, Sakabe, Katayama, and Tanaka, 1975). The methylene-bridge of [3.4]paracyclophadiyne has a disordered structure.
A Method of Estimating the Diffusion Coefficient of Disperse Dyes into Hydrophobic Fibers from the Initial Sorption Data of Dyeing by Means of the Polynomial Least-squares Method
Authors: Shibusawa Takao 
Published: July 2006

Abstract
For the initial and the medium stage of diffusion, Hill’s equation was approximated by the simple polynomial in the form of Mt⁄M∞≈P1(Dt⁄r2)1⁄2–P2(Dt⁄r2) where P1 and P2 are constants depending on the interval in which the approximation is used, while the other symbols have a usual meanings. On the other hand, several experimental Mt’s were plotted against square root of t, and an experimental formula describing the regression curve passing through a discrete set of experimental points, Mt=A0+A1t1⁄2–A2t, was obtained by means of curve fitting with a polynomial of degree 2. From the polynomial approximation and the experimental formula, the following equations which are capable of calculating the approximate value of M∞ and D were obtained.
(D⁄r2)1⁄2≈(A2P1)⁄(A1P2), M∞≈(A12P12)⁄(A2P12)
Then the method for obtaining more probable values of D and M∞ was described, in this method the approximations to inverse function of Hill’s equation and the curve fitting with polynomial of degree 2 were used.
A Molecular Orbital Study of the Conformation and g-Factors of the H2SSH2+ and H2SSH Radicals
Authors: Kikuchi Osamu 
Published: July 2006

Abstract
The conformation and g-factors of the H2SSH2+ and H2SSH radicals were analyzed by means of a restricted open-shell SCF MO method with the semiempirical MINDO/3 and INDO approximations, and the observed g-factors of the family of radicals consisting of R2SSR2+, R2SSR, and RSSR− were compared on the basis of their molecular and electronic structures.
Charge-transfer Interaction and Ground-state Energy Stabilization in Crystalline Complex Ion Radical Salts
Authors: Iida Yôichi 
Published: July 2006

Abstract
Although predominant cohesive energy is Madelung energy, the ground state of crystalline complex ion radical salt is further stabilized by the charge-transfer interaction between neutral molecule and ion radical, together with that between ion radicals. The magnitude of this stabilization energy was estimated with (Phenothiazine)2+· Br−.
The Core-level Binding Energies and the Structures of Nickel Complexes
Authors: Yoshida Tooru , Yamasaki Kiyoshi 
Published: July 2006

Abstract
The X-ray photoelectron spectra of thirty two nickel complexes were measured in order to examine the relation between the structures and the core-level binding energies of the complexes. The differences between the energies of Ni(2p) and Ni(3p) electrons for the complexes with an octahedral structure were about 1 eV larger than for those with a square planar one.
Synthesis and Absorption Spectra of Annelated 5-Amino-1,4-diazaanthraquinones and Related Compounds
Authors: Nakazumi Hiroyuki , Kondo Kazuyoshi , Kitao Teijiro 
Published: July 2006

Abstract
New annelated 5-amino 1,4-diazaanthraquinones and related derivatives were prepared from 2,3,5-triamino-1,4-naphthoquinone or 5-amino-2,3-dichloro-1,4-naphthoquinone. Their visible absorption spectra were examined by the PPP-SCF-MO calculation with a variable β approximation.
Phenalenones. III. The Anomalous Diazotization of 3-Substituted 2-Aminophenalenones
Authors: Kuroki Masatane , Tsunashima Yutaka 
Published: July 2006

Abstract
The diazotization of 3-substituted 2-amino-1H-phenalen-1-ones (substituents=Cl, Br, PhS, or OH) gave 2-diazo-1H-phenalene-1,3(2H)-dione. It is most probable that the reaction involves the intramolecular rearrangement of a transient diazohydroxide intermediate and the consequent elimination of the substituent at the 3-position.
Study of Cationic Surfactant Ion Selective Poly(vinyl chloride) Membrane Electrode Containing Dibenzo-18-crown-6
Authors: Maeda Tamaki , Ikeda Makoto , Shibahara Mitsuhiro , Haruta Takahide , Satake Iwao 
Published: July 2006

Abstract
Study was made of the potentiometric selectivities of poly(vinyl chloride) membrane with and without dibenzo-18-crown-6. It was found that these membrane electrodes were highly selective for cationic surfactant ions and showed a Nernstian response to surfactant ion such as 1-dodecylpyridinium ion even in the concentration range as low as 10−6 mol/dm3. The selectivity coefficients of inorganic cations, taken with respect to 1-dodecylpyridinium ion, were of the order of 10−5 or less, while that of surfactant ion was found to depend not only on hydrophobic alkyl chain length but also on the type of hydrophilic head group. For cationic surfactants with the same hydrocarbon chain length, the membrane without crown ether exhibited the order of selectivity: 1-alkylpyridinium ion&gt;alkyltrimethylammonium ion&gt;alkylammonium ion. In the case of the membrane with crown ether, the selectivity sequence became alkylammonium ion&gt;1-alkylpy ridinium ion&gt;alkyl trimethylammonium ion. For a homologous series of cationic surfactants, the selectivity coefficient increased regularly with increasing alkyl chain length.
The Crystal Structures of Hexamethyleneiminium p-Chlorobenzoate and Dimorphs of Hexamethyleneiminium p-Bromobenzoate
Authors: Kashino Setsuo , Sasahara Norimitsu , Kataoka Shin-ichi , Haisa Masao 
Published: July 2006

Abstract
The crystal structures of hexamethyleneiminium p-chlorobenzoate (1), and the monoclinic [2(m)] and orthorhombic [2(o)] forms of hexamethyleneiminium p-bromobenzoate have been determined from visually estimated Cu Kα data. The crystal data are: P21c, a=10.10(2), b=16.78(1), c=9.01(2) Å, β=118.4(2)°, Z=4 for 1; C2/c, a=25.47(2), b=7.01(1), c=16.29(1) Å, β=109.1(1)°, Z=8 for 2(m); and Pbca, a=11.55(1), b=27.40(1), c=8.57(1) Å, Z=8 for 2(o). The structures of 1, 2(m), and 2(o) were refined to R values of 0.072, 0.100, and 0.083 for 1628, 1009, and 1013 non-zero reflections, respectively. In the crystals of 1, the type of hydrogen bond and the molecular arrangement in (010) plane are the same as those in piperazinediylium terephthalate. In 2(m), two pairs of the base and acid ions related by a twofold axis are linked together by N–H···O hydrogen bonds. The crystal structure of 2(o) is very similar to that of piperidinium and pyrrolidinium p-substituted benzoates in Pbca, but there is a difference in the combination mode of the base and acid ions participating in the hydrogen bonds. In all the crystals, the hydrogen bond extending along the long axis of the acid ion is shorter than that nearly perpendicular to the axis. Hexamethyleneimine rings in 1, 2(m), and 2(o) take a similar twist-chair conformation.
Studies on Chemiluminescent Compounds. I. Syntheses of Acylsubstituted Anthracene Derivatives and Their Chemiluminescence
Authors: Hiramatsu Toshiyuki , Harada Toshiaki , Yamaji Teizo 
Published: July 2006

Abstract
New anthracene derivatives with a –COCH– group, such as 1,5-dipropionylanthracene, 1,8-dipropionylanthracene, 1,5-di-isobutyrylanthracene, 1,8-diisobutyrylanthracene, 1,5-bis[3-(methoxycarbonyl)propionyl]anthracene, 1,8-bis[3-(methoxycarbonyl)propionyl] anthracene, 1,5-bis(cyclohexylcarbonyl) anthracene, 3,7-diisopropyl-1,5-diisobutyrylanthracene, and 5-dimethylamino-4-isobutyryl-1-methoxyanthracene (10) have been synthesized. Their direct chemiluminescences were studied by air oxidation in alkaline solutions. The properties of the chemiluminescence have been found to be influenced by not only the class of the C–H bond adjacent to the carbonyl group but also by the electronic properties of the aromatic ring system, the solvent, and the additive. 10 exhibited the longest chemiluminescence. This chemiluminescent phenomenon might be explained by a chemically initiated electron exchange luminescence (CIEEL) mechanism.
Crystal and Molecular Structures of Octaethylporphinium(monocation) Triiodide and Its Benzene Hemisolvate
Authors: Hirayama Noriaki , Takenaka Akio , Sasada Yoshio , Watanabe Ei-ichi , Ogoshi Hisanobu , Yoshida Zen-ichi 
Published: July 2006

Abstract
The structure of the triclinic form of octaethylporphinium (monocation) triiodide was determined by X-ray analysis. The structure of the previously determined orthorhombic form was refined using diffractometer data. The final R values for the triclinic and the orthorhombic forms were 0.060 and 0.069, respectively. The present analysis has established the inherent structure of porphyrin monocations; three pyrrole rings are coplanar and the plane of the fourth ring is tilted from the mean plane of the other three. The magnitude of the tilt angle is 12.5° for the triclinic form and 16.1° for the orthorhombic form.
Proton-transfer Reactions of 5-(m- and p-Nitrophenylazo)salicylic Acids Coupled with Inclusion Reactions with α- and β-Cyclodextrins
Authors: Yoshida Noboru , Fujimoto Masatoshi 
Published: July 2006

Abstract
The title azo compounds, 5-(m- and p-nitrophenylazo)salicylic acids (m- and p-NPAS), were found kinetically to be included into a cavity of α- or β-cyclodextrin. The rate constants for the inclusion reactions were found to be in the order of magnitude 107 and 106 mol−1 dm3 s−1 for α-cyclodextrin and β-cyclodextrin systems, respectively. The 1H and 13C NMR data showed that the hydrophobic nitrobenzene ring moiety of m- and p-NPAS is situated in the α- and the β-cyclodextrin cavity. The proton-transfer reactions of m- and p-NPAS were accelerated in the presence of α- and β-cyclodextrins. This indicates the possibility that the inclusion force of cyclodextrins contributes to weakening the intramolecular hydrogen bond of m- and p-NPAS.
Multidentate Ligand Kinetics. III. The Ligand-substitution Reaction between the Ethylenediaminetetraacetatocuprate(II) Ion and the Tetraethylenepentaminezinc(II) Ion
Authors: Katsuyama Tetsuo , Kumai Toshihiko 
Published: July 2006

Abstract
The kinetics and mechanism of the ligand-substitution reaction between the ethylenediaminetraacetatocuprate(II) ion (Cu(II)-edta) and the tetraethylenepentaminezinc(II) ion (Zn(II)-tetren) were studied spectrophotometrically over the pH range from 7.0 to 9.0 at I=0.2 M (1 M= mol dm−3) and 25.0 °C. The substitution reaction was shown to proceed by means of a chain-reaction mechanism where the chain-propagating steps are the reaction of Cu(II)-edta with tetren and the reaction of Zn(II)-tetren with edta. Each chain-propagating step was investigated. The ligand-substitution reaction of Zn(II)-tetren with edta was studied by the use of the chain reaction. The rate law is expressed as
−\fracd[Zn(II)-tetren]dt=kL[Zn(tetren)2+][edta4−]+kHL[Zn(tetren)2+][Hedta3−]+k′HL[Zn(Htetren)3+][Hedta3−].
The rate constants, kL,kHL, and k′HL were determined at 25.0 °C and I=0.2 M as: kL≈3×102 M−1 s−1, kHL=(4.1±0.7)×102 M−1 s−1, and k′HL=(1.7±0.2)×105 M−1 s−1.
Studies of the Separation Mechanism in Ion-exchange Chromatography. III. Elution Order of cis-Bis(ethylenediamine)cobalt(III) and cis-α-Triethylenetetraminecobalt(III) Complexes on SP-Sephadex C-25 and IEX 510 Resins
Authors: Yoneda Hayami , Wakida Shin-Ichi , Nakazawa Hiroshi , Sakaguchi Ushio 
Published: July 2006

Abstract
Chromatographic separation of cis-dianionobis(ethylenediamine)cobalt(III) and cis-α-dianionotriethylenetetraminecobalt(III) complexes has been investigated by using SP-Sephadex C-25 and IEX 510 cation-exchange resins. The elution order of the complex cations on both resins are rather similar to each other and the adjusted retention volumes of these complexes correlate very closely with the crystallographic volumes (the unit cell volumes divided by the number of molecules in a unit cell) of [Co(X)(NH3)5]Cl2, where X=CN−, Cl−, NO2−, N3−, and NCS−. This has been taken to indicate that the affinity of the complex cation to the functional group of the resins increases as the size of the cation, and hence the character of water-structure breaker of the cation, increases. Thus, the elution order obtained seems to be determined primarily by the difference in the affinities of the complex cations to the resins, rather than by the difference in the association constants for the ion-pairs formed between the complex cation and the eluent anion.
Synthesis of 1,1′-, 2,2′-, 1,2′-, and 2,6′-Biazulenes and Their Derivatives by Ullmann Reaction
Authors: Morita Tadayoshi , Takase Kahei 
Published: July 2006

Abstract
Four kinds of biazulenes, 1,1′- (1a), 2,2′- (2a), 1,2′- (3a), and 2,6′-biazulenes (4a), and their derivatives were synthesized by utilizing Ullmann-type coupling of haloazulene derivatives. Ullmann reaction of ethyl 3-iodo-(5a) and 2-iodoazulene-1-carboxylates (6b) gave diethyl 1,1′-biazulene-3,3′-dicarboxylate (1b) and diethyl 2,2′-biazulene-1,1′-dicarboxylate (2b), respectively, in excellent yields. The reaction of 2-iodoazulene gave 2a directly. Diethyl 2-chloroazulene-1,3-dicarboxy late (7a) and its 5-alkyl derivatives also reacted to give tetraethyl 2,2′-biazulene-1,1′,3,3′-tetracarboxylate (2d) and its 5,5′-dialkyl derivatives, respectively. A mixed Ullmann reaction of 5a and 6b afforded a mixture of 1b, 2b, and diethyl 1,2′-biazulene-1′,3-dicarboxylate (3b). Similarly, a mixed Ullmann reaction of 7a and diethyl 6-iodoazulene-1,3-dicarboxylate gave a mixture of 2d and tetraethyl 2,6′-biazulene-1,1′,3,3′-tetracarboxylate (4b). The parent hydrocarbons of biazulenes, 1a, 2a, 3a, and 4a, could be derived from the corresponding ethoxycarbonyl derivatives, 1b, 2b, 2d, 3b, and 4b, respectively, by decarboxylation. The planarity of biazulenes and their ester derivatives is also discussed on the basis of the spectral data.
The Preparation of Cyclic Dithia and Thiaza Compounds by the Reaction of Potassium Carbonate with Heterocumulenes and Alkylene Dibromides or Carbonate Catalyzed by Organostannyl Compounds
Authors: Fujinami Tatsuo , Sato Shinichi , Uchida Norimasa , Sakai Shizuyoshi 
Published: July 2006

Abstract
Cyclic 1,3-dithia- and 1,3-thiaza-2-ylidene compounds were obtained by the heterogeneous reaction of solid potassium carbonate, a sulfur-containing heterocumulene, such as aryl isothiocyanate, carbon disulfide, or carbonyl sulfide, and alkylene dibromides or ethylene carbonate in the presence of bis(tributylstannyl) compounds. The effect of an organostannyl catalyst on these reactions is discussed.
Synthesis of β- and α-Rotunols. Revision of the Structure of a Stress Metabolite “1-Keto-α-cyperone”
Authors: Murai Akio , Ono Mitsunori , Abiko Atsushi , Masamune Tadashi 
Published: July 2006

Abstract
The synthesis of β- and α-rotunols, two sesquiterpene alcohols isolated from nutgrass (Cyperus rotundus Linne), is described. This synthetic study also involves revision of the structure of a stress metabolite “1-keto-α-cyperone” isolated from Burley and flue-cured tobaccos (Nicotiana tabacum L.).
Reaction of 1-Lithio-1-arylthio(or alkylthio)methyltrimethylsilane with Acid Derivatives. A Novel Synthesis of Functionalized Vinyl Sulfides
Authors: Agawa Toshio , Ishikawa Minori , Komatsu Mitsuo , Ohshiro Yoshiki 
Published: July 2006

Abstract
Reactions of 1-lithio-1-phenylthiomethyl- (1a) and 1-lithio-1-methylthiomethyltrimethylsilane (1b) with amides, an ester, acid anhydrides, a urea, and a carbonate are described which provide useful routes to functionalized vinyl sulfides. The reaction of 1 with amides gave β-functionalized vinyl sulfides, 1-dialkylamino-2-phenylthio (or methylthio)ethylenes, in 40–95% yields and the reaction could be extended to the sulfonyl derivatives of 1 to afford 1-dialkylamino-2-phenylsulfonyl(or methylsulfonyl)ethylenes. Although ethyl benzoate and some acid anhydrides were not good substrates for this reaction, tetramethylurea and diethyl carbonate gave α-functionalized vinyl sulfides, 1-amidovinyl- and 1-(ethoxycarbonyl)vinyl sulfides, in moderate yields when treated with 1a followed by addition of benzaldehyde.
Formation of Electronically Excited Fragments (H, CH, NH) by the Electron Impact of Pyrrole and Pyrrolidine
Authors: Tokue Ikuo , Ikarashi Masami , Ito Yoshio 
Published: July 2006

Abstract
In the wavelength region of 200–600 nm, photoemissions from electronically excited fragments (H, CH, NH, CN, and C2) were observed when pyrrole and pyrrolidine were excited by electron impact (0–70 eV). Hydrogen atoms and CH and NH radicals from pyrrole and pyrrolidine are produced via a single collision excitation. The appearance potentials for these fragments from pyrrole are 19.4±0.8 eV for the hydrogen Balmer β (Hβ), 19.7±0.8 eV for the CH(A2Δ-X2Π) band, and 20.0±1.0 eV for the NH(A3Π-X3Σ) band. Those from pyrrolidine are 18.7±0.8 eV for Hβ, 23.0±0.8 eV for the CH(A-X) band, and 21.8±1.0 eV for the NH(A-X) band. Dissociation processes forming these electronically excited fragments are discussed.