bluuebunny/crossref_metadata_2025 huggingface dataset:
The Origin of the Polarity of a Radical in Hydrogen Abstraction Reactions
Authors: Shinohara Hiroyuki , Imamura Akira
Published: July 2006

The electrophilicity of the H atom in hydrogen abstraction reactions was studied by the CNDO/2 method. The origin of the electrophilicity of the H atom was well understood using the stabilization energy due to the delocalization of electrons (SEDE) between the radical and substrate; this energy was calculated along the reaction path. The electrophilic energy (SEDE from the substrate to the radical) governs the relative reactivities of substrates, CH4<CH3CH3<CH3CH2CH3<(CH3)3CH which correspond to the order of the increase in the electron density. The electrophilic energy is also important in hydrogen abstraction by the H atom from aliphatic alcohols. In the case of the Cl2− radical, the nucleophilic energy (SEDE from the radical to the substrate) determines the relative reactivities of substrates, CH3OH<C2H5OH<i-C3H7OH. The polarity of a free radical is tentatively clarified by using its ionization potential.
The Crystal Structure and Absolute Configuration of (−)589-Bis(2,4-pentanedionato)(1,3-propanediamine)chromium(III)Iodide Monohydrate
Authors: Matsumoto Keiji , Ooi Shun’ichiro
Published: July 2006

The crystal structure of (−)589-[Cr(acac)2(tn)]I·H2O has been determined from the X-ray diffraction data collected on a diffractometer. The crystal is orthorhombic, with the space group P212121 and with a=20.834(6), b=12.015(3), c=7.621(2) Å, and Z=4. Block-diagonal least-squares refinement for 1426 independent reflections with Fo2>3σ(Fo2) converged to R=4.91%. The complex cation has the Λ absolute configuration. The 1,3-propanediamine ligand assumes a chair conformation. One of the 2,4-pentanedionato chelate rings is almost planar, while in the other the 2,4-pentanedionato plane is bent away from the plane defined by Cr and 2 O donor atoms because of the intramolecular repulsion, the interplanar angle being 9.4°. The interrelation between the absolute configuration and the circular dichroism was discussed for the [Cr(acac)n(tn)3−n](3−n)+-type complexes.
Quantification of Phenols in Gas from Rotten Liquid Swine Manure by Computer-controlled Gas Chromatography-Mass Spectrometry
Authors: Yasuhara Akio , Fuwa Keiichiro
Published: July 2006

Analytical studies on phenol, o-cresol, m-cresol, p-cresol, and p-ethylphenol from liquid swine manure were performed with selected ion monitoring in computer-controlled gas chromatography-mass spectrometry. Phenol, p-cresol, and p-ethylphenol in effluent gas from liquid swine manure and in the head-space gas over liquid swine manure were determined.
Pyrrolizidine Alkaloids. The Synthesis and Absolute Configuration of All Stereoisomers of Monocrotalic Acid
Authors: Matsumoto Takashi , Takahashi Makoto , Kashihara Yutaka
Published: July 2006

All stereoisomers (3a, b–6a, b) of monocrotalic acid have been synthesized. Methylation of (±)-cis-2,3,4-trimethyl-2-pentenedioic acid with diazomethane followed by cis-hydroxylation with potassium permanganate afforded two epimeric γ-lactone esters in a ratio of ca. 1:5. These esters were then hydrolyzed with dilute hydrochloric acid to the corresponding acids, (±)-3 and racemic monocrotalic acid (4). Optical resolution of (±)-3 with brucine afforded 3a (2R,3R,4S) and 3b (2S,3S,4R). The racemic monocrotalic acid was also resolved by means of brucine to give natural monocrotalic acid (4a: 2R,3R,4R) and its enantiomer (4b: 2S,3S,4S). Subsequently, (±)-trans-2,3,4-trimethyl-2-pentenedioic acid was resolved with cinchonidine to give 8a and 8b, whose stereochemistry was assigned respectively as S- and R-configuration by correlation to the known (R)-(−)-2-phenylpropanoic acid. Methylation of 8a followed by cis-hydroxylation and hydrolyses afforded γ-lactone acids, 5a (2R,3S,4S) and 6b (2S,3R,4S). Similarly, the enantiomer 8b was also converted into the corresponding acids, 5b (2S,3R,4R) and 6a (2R,3S,4R). The stereochemical course of the above hydroxylations with potassium permanganate was well explained by a modification of Gram’s rule of asymmetric induction. The CD spectra of 3a,b–6a,b were also discussed.
Super Exchange in Copper(II) Dimers. II. Synthesis, Characterization and Magnetic Properties of Binuclear Adducts of Copper(II) Halides with 1,2-Benzoquinone Dioximes. Ligandinduced Ferromagnetic Exchange Coupling
Authors: Bélombé Michel Megnamisi
Published: July 2006

Various 1,2-benzoquinone dioximes (bqdH) have been combined with CuCl2 or CuBr2 to afford the following new dimeric adducts: di-μ-chlorobis[chloro(1,2-benzoquinone dioxime)copper(II)], [CuCl2(bqdH)]2; di-μ-chlorobis[chloro(4-chloro-1,2-benzoquinone dioxime)copper(II)], [CuCl2(ClbqdH)]2; di-μ-chlorobis[chloro(4-methyl-1,2-benzoquinone dioxime)copper(II)], [CuCl2(MebqdH)]2; di-μ-chlorobis[chloro(4,5-dimethyl-1,2-benzoquinone dioxime)copper(II)], [CuCl2(Me2bqdH)]2; di-μ-bromobis[bromo(1,2-benzoquinone dioxime)copper(II)], [CuBr2(bqdH)]2; di-μ-bromobis[bromo(4-chloro-1,2-benzoquinone dioxime)copper(II)], [CuBr2(ClbqdH)]2; di-μ-bromobis[bromo(4,5-dimethyl-1,2-benzoquinone dioxime)copper(II)], [CuBr2(Me2bqdH)]2. These brown solids were characterized by variable-temperature magnetic susceptibility measured within 4.2–300 K, as well as by room temperature near infrared and electron spin resonance spectra from which the dimeric structure of the compounds was inferred. The intradimer magnetic exchange interaction was found to occur by a super exchange mechanism mediated by the valence p wave functions of the bridging halide ions. It was observed that the electrophilic character of the benzoquinonoid ligands affects the magnetic exchange via backbonding and through mesomeric π electron delocalization. It was found, most interestingly, that the tendency to ferromagnetic exchange interaction within a dimer is the stronger, the more electrophilic the bqdH ligands can be made.
Photoisomerization of Bis(t-butyl isocyanide)dichlorobis-(triphenylphosphine)ruthenium(II)
Authors: Tsuihiji Tamotsu , Akiyama Takeo , Sugimori Akira
Published: July 2006

UV-irradiation of bis(t-butyl isocyanide)dichlorobis(triphenylphosphine) ruthenium(II) brings about isomerization. The composition of the photo-stationary state is wavelength-dependent. A mechanism via the photoelimination of triphenylphosphine is proposed.
The Molecular and Crystal Structure of the Green Form of Bis(N-cyclohexylsalicylideneaminato)copper(II)
Authors: Tamura Hatsue , Ogawa Kazuhide , Takeuchi Akira , Yamada Shoichiro
Published: July 2006

Bis(N-cyclohexylsalicylideneaminato)copper(II) crystallizes in two forms: one is a brown crystal (Form I), and the other is a green one (Form II). The crystal structure of Form II has been determined by X-ray analysis. The green crystals are monoclinic; space group, P21/n. The cell dimensions are a=23.134(6), b=9.525(3), c=21.472(8) Å, β=99.42(1)°, and Z=8. The structure was deduced by the heavy-atom method and was refined to a final R value of 0.082 for 1883 observed reflections by the block-diagonal least-squares method. The molecular structure in Form II is dimeric, in contrast with the case of Form I, which is composed of a monomeric molecule. The two monomeric halves are joined by two Cu–O bonds with distances of 2.60(1) and 2.64(1) Å. Each copper(II) ion is penta-coordinated in a distorted square-pyramidal configuration. The molecular structures in Form I and II have been compared with those of the related Cu(II) compounds.
Kinetics of Ligand Exchange between Tris(acetylacetonato[2-14C])cobalt(III) and Acetylacetone in Acetonitrile, Evidence for SN1 Mechanism
Authors: Kido Hiroaki , Saito Kazuo
Published: July 2006

Tris(acetylacetonato[2-14C]) cobalt (III) undergoes ligand isotopic exchange with acetylacetone (Hacac) in acetonitrile at 85–100 °C without decomposition and solvolysis. The exchange rate is proportional to the complex concentration (0.002–0.007 M, 1 M=1 mol dm−3), the first-order rate constant ko being independent of [Hacac] (0.001–0.97 M). ko=1.6×10−5 s−1 at 93.2 °C. The activation enthalpy and entropy are 38±4 kcal mol−1 (1 cal= 4.18J) and 23±8 cal K−1 mol−1, respectively. Trichloroacetic acid (<0.02 M) gives acid catalysis. The ratedetermining step should be the SN1 Co–O cleavage in a chelate ring to give a five coordinate intermediate.
Reaction Processes of Vanadium Bichloride Oxide and Vanadium Trichloride with Oxygen
Authors: Yajima Akimasa , Matsuzaki Ryoko , Saeki Yuzo
Published: July 2006

The products formed by the heating of VCl2O in an oxygen stream at various temperatures were examined by chemical and X-ray analysis. The reaction products between VCl3 and oxygen were examined in the same manner. The reaction process between VCl2O and oxygen may be represented as follows: VCl2O reacts with oxygen above ca. 170 °C to form V2O5 and VCl3O, 12VCl2O(s)+3O2(g)→2V2O5(s)+8VCl3O(g), and this reaction is accompanied by the reaction, 4VCl2O(s)+3O2(g)→2V2O5(s)+4Cl2(g). The reaction process between VCl3and oxygen may be represented as follows: VCl3 reacts with oxygen above ca. 100 °C to form VCl3O, 2VCl3(s)+O2(g)→2VCl3O(g), and this reaction is accompanied by the reaction, 2VCl3(s)+O2(g)→2VCl2O(s)+Cl2(g).
Catalytic Efficiency of Cationic Micellar Catalysts Bearing a Mercapto Group as the Reaction Center
Authors: Murakami Yukito , Nakano Akio , Matsumoto Kiyoshi , Iwamoto Kiyoshi
Published: July 2006

In order to clarify micro-environmental effects on the reactivity of mercapto groups in enzymes, cationic surfactants bearing a mercapto group, N-hexadecyl-Nα-(3-trimethylammoniopropionyl)-l-cysteinamide bromide (CM·Cys-1) and N-dodecyl-Nα-(6-trimethylammoniohexanoyl)-l-cysteinamide bromide (CM·Cys-2), were synthesized and their kinetic behavior investigated. The surfactants above their critical micelle concentrations markedly catalyzed the decomposition p-nitrophenyl hexanoate (PNPH) and acetate (PNPA), the concentrationrate profiles being found to be those for typical micelle-catalyzed reactions. The rate constants for the degradation of PNPH as catalyzed by CM·Cys-1 and -2 in the micellar phase are 0.482 and 0.197 s−1, respectively, in 9.8% (v/v)ethanol–1.0%(v/v)dioxane–1.0%(v/v)methanol-water at 30.0±0.1 °C, pH 8.65, and μ0.10 (KCl). The difference in catalytic activity can be attributed partly to the micro-environmental effect on the pKa value of the mercapto group lying at the reaction center. The rate constants for the thiolate anions (true reactive species) of CM·Cys-1 and -2 to react with PNPH were identical with each other irrespective of the nature of the surfactants. The electrostatic effect provided by the cationic charge in the Stern layer, which acts to reduce the pKa value of the reactive mercapto group, seems to play a more important role than the desolvation effect on the thiolate anion by the hydrophobic field.
Reaction of Diazo Ketones in the Presence of Metal Chelates. VII. 1,3-Dipolar Cycloaddition of 1-Methoxybenzo[c]pyrylium-4-olate with Acetylenic Dipolarophiles
Authors: Ibata Toshikazu , Jitsuhiro Kimiko
Published: July 2006

The Cu(acac)2 catalyzed decomposition of o-methoxycarbonyl-α-diazoacetophenone (3) in the presence of acetylenic dipolarophiles gave cycloadducts of the dipolarophiles with 1-methoxybenzo[c]pyrylium-4-olate generated by the intramolecular carbene-carbonyl reaction of the corresponding carbene. The direction of the cycloadditions of unsymmetrically substituted acetylenes has been determined on the basis of the NMR coupling pattern and chemical shift of the bridgehead methine protons of the adducts. Treatment of 3 with strong dipolarophiles such as dibenzoylacetylene or dimethyl acetylenedicarboxylate gave spiro pyrazoles by the direct cycloaddition of 3 and acetylenes followed by the elimination of methanol.
The Reactions of 1,2-Diphenyl-1-azaspiro[2,2]pentane and 2-Phenyl-1-azaspiro[2.2]pent-1-ene with C,N-Diarylnitrilimines
Authors: Tsuge Otohiko , Watanabe Hiroyuki , Kiryu Yoko
Published: July 2006

The reactions of highly strained 1,2-diphenyl-1-azaspiro[2.2]pentane (1) and 2-phenyl-1-azaspiro[2.2]pent-1-ene (2) with C,N-diarylnitrilimines (3) were described. The reaction of 1 with 3 gave the corresponding 4,5,7,8-tetraphenyl-4,6,7-triazaspiro[2.5]oct-5-ene, 1,5,7,8-tetraphenyl-5,6,8-triazaspiro[3.4]oct-6-ene, 1,3,5-triphenyl-2-pyrazoline, 1,3,4-triphenyl-1,2,4-triazolin-5-one, and/or 1,3,4,6,8-pentaphenyl-1,2,4,6,7-pentaazaspiro[4.4]nona-2,7-diene, whose yields depended on the reaction conditions. The pathways for the formation of products are also postulated. The azaspiropentene 2 readily reacted with 3 to give the corresponding 1,2,4-triphenyl-2,3,5-triazabicyclo[4.2.0]octa-3,5-diene arising from the rearrangement of initial 1,3-cycloadduct.
The Crystal Structures of (+)589- and (−)589-trans(O)-Ethylenediaminebis(glycinato)cobalt(III) Hydrogen-d-tartrates and Their Thermal Behavior
Authors: Kuramoto Masahiro
Published: July 2006

The crystal structures of two diastereoisomeric salts, (+)589-trans(O)-[Co(gly)2en]H-d-tart·3H2O (1) and (−)589-trans(O)-[Co(gly)2en]H-d-tart·H2O (2), have been determined by three-dimensional X-ray analysis. The less-soluble salt (1) is monoclinic; space group, P21; Z=2, a=12.351(5), b=7.671(3), c=10.189(5) Å, and β=110.71(4)° (R=0.043, 2241 reflections). The more-soluble salt (2) is monoclinic; space group, P21; Z=2, a=11.135(4), b=10.037(3), c=7.716(3) Å, and β=98.61(3)° (R=0.064, 2076 reflections). A comparison of the (unit cell volume)/Z values of the two crystals shows that the crystal 1 is more tightly packed than the crystal 2. In both salts, adjacent complex cations form quite similar chain structures linked by (N–H…O) hydrogen bonds. The H-d-tart anions in 1 take a characteristic “head-to-tail” arrangement of an infinite chain of {H-d-tart}∞ along the b-axis. In contrast, this arrangement is not found in the more-soluble salt (2). From these findings, it can be considered that the discrimination of optical isomers in the H-d-tart system originates from the spiral chain structure of {H-d-tart}∞. The absolute configurations of (+)589- and (−)589-trans(O)-[Co(gly)2en]+ are determined to be Λ-δ and Λ-λ respectively. TG and DSC measurements were carried out for both salts, and the ΔH values of the dehydration step were estimated to be 64.4 kJ mol−1 for 1 and 73.0 kJ mol−1 for 2.
Catalytic Hydrogenolysis of 1,1-Dichloro-3-methyl-2-phenylcyclopropane
Authors: Isogai Koji , Hirabayashi Shigeru
Published: July 2006

The title compound was hydrogenolyzed over PdO or Raney nickel. The C2–C3 bond of the cyclopropane ring underwent cleavage exclusively over PdO. Cleavage of the C1–C2 and C2–C3 bonds occurred competitively over Raney nickel. A probable pathway is suggested.
Reaction of Nitrosodurene with Grignard Reagents
Authors: \={O}kubo Masao , Takahashi Tomoko
Published: July 2006

Nitrosodurene was allowed to react with alkyl- and arylmagnesium halides and the reaction was followed by ESR. The spectrum of nitrosodurene anion radical was observed, the stability sequence of alkyl duryl nitroxides being discussed on the basis of the coupling constants of α-hydrogen atoms of alkyl groups.
The Reaction of 2,4,6-Triphenyl-1,3-thiazinylium Perchlorate with Active Methylenes
Authors: Shibuya Isao
Published: July 2006

The reaction of 2,4,6-triphenyl-1,3-thiazinylium perchlorate (4) with several active methylenes was studied. Methyl cyanoacetate or benzoylacetonitrile reacted with 4 to give 3-cyano-2,4,6-triphenylpyridine, while malononitrile led to 1-mercapto-1,3-diphenyl-4,4-dicyanobutadiene and cyanoacetamide led to 2-hydroxy-3-cyano-4,6-diphenyl-pyridine. The reaction of diethyl malonate, nitromethane, or nitroethane with 4 gave 2-[bis(ethoxycarbonyl)methyl]-, 2-nitromethyl- or 2-(1-nitroethyl)-2,4,6-triphenyl-2H-1,3-thiazine respectively. These results showed that the reaction manner of 4 to these active methylenes is significantly different from that of 2,4,6-triphenyl-1,3-oxazinylium salt.
The Proton-transfer Reactions of the Univalent Anions of ortho-Hydroxy Azo Compounds in Dioxane–Water Media
Authors: Yoshida Noboru , Fujimoto Masatoshi
Published: July 2006

The proton-transfer reactions of the univalent anions of 4-(2-pyridylazo)resorcinol (PAR) and 4-(2-hydroxy-5-ethyIphenylazo)benzenesulfonic acid (HEB) with hydroxide ion in dioxane-water media, HA−+OH−\oversetkf\undersetkr\ightleftharpoonsA2−+H2O, were studied by means of temperature-jump method. The dependencies of the rate constants, kf and kr on the solvent compositions were interpreted by a mechanism involving the breaking of an intramolecular hydrogen-bond.
The Cyclodextrin-accelerated Cleavage of Thiocarboxylic S-Esters
Authors: Komiyama Makoto , Bender Myron Lee
Published: July 2006

The effect of α- and β-cyclodextrins on the cleavage of the thiocarboxylic S-esters, S-p-nitrophenyl thioacetate (1) and S-ethyl p-nitrothiobenzoate (3), was compared with their effect on the cleavage of the corresponding oxygen esters, p-nitrophenyl acetate (2) and ethyl p-nitrobenzoate (4). The rate constants of α- or β-cyclodextrin-accelerated cleavage of 1 (1.5×10−2 or 4.8×10−2 s−1 at pH 10.5, 25 °C) were almost identical with the values of 2 (1.6×10−2 or 4.2×10−2 s−1), definitely showing the rate-determining formation of tetrahedral intermediates. The cleavage of 3 was accelerated by α- and β-cyclodextrins, whereas the cleavage of 4 was decelerated by β-cyclodextrin but was not affected by α-cyclodextrin. The contrast in the effect of cyclodextrins on 3 and 4 was ascribed to the difference of the rate of breakdown of the tetrahedral intermediates to products, caused by different pK’s of the leaving groups of 3 (10.5) and 4 (16.0). The formation of tetrahedral intermediates confirmed in the cyclodextrinaccelerated hydrolyses of esters further strengthened the previous proposal that cyclodextrin is an excellent model of serine proteases, since these intermediates are also formed in enzymatic reactions.
Chemistry of Dienyl Anions. II. Crystalline Bis(dienyl)magnesium. Selective Dienylation and Structure in Solution and in the Solid State
Authors: Yasuda Hajime , Yamauchi Michihide , Nakamura Akira , Sei Tsuyoshi , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami
Published: July 2006

Seven different crystalline bis(dienyl)magnesium·TMEDA complexes of open chain or cyclic structure were prepared by metal exchange reaction of corresponding potassium dienides. They are fluxional in solution due to the rapid 1,3-rearrangement. Terminally σ-bonded trans or (E) structure exists primarily in the open chain complexes while centrally σ-bonded cis structure in cyclic dienylmagnesium·TMEDA complexes. The former gave 1,3-dienes exclusively but the latter gave 1,4-dienes upon hydrolysis. Molecular structure of bis(2,4-dimethyl-2,4-pentadienyl)magnesium determined by X-ray crystallography showed that it has terminally σ-bonded structure. Addition of dienylmagnesium compounds to acetone followed by hydrolysis gave 1,4-diene derivatives regioselectively but that to diisopropyl ketone gave 1,3-diene derivatives selectively. Unsaturated alcohols with an elongated carbon chain were synthesized by thermal cracking of cyclic ether complexes. 1,3,7-Trienes can be obtained selectively by reaction of appropriate allyl halides in the presence of CuCl catalyst and regioselective dienylation occurred by using TiCl2(η5-C5H5)2 as catalyst.
Pseudo-sugars. VI. Synthesis of Six Isomers of 5-Hydroxymethyl-1,2,3,4-cyclohexanetetrol (Pseudo-hexopyranose) and Their Derivatives
Authors: Ogawa Seiichiro , Ara Masayasu , Kondoh Takashi , Saitoh Michio , Masuda Reiko , Toyokuni Tatsushi , Suami Tetsuo
Published: July 2006

Six isomers of 5-hydroxymethyl-1,2,3,4-cyclohexanetetrol, including naturally occurring (1,2/3,4,5)-isomer, and their several derivatives were synthesized from the exo-2-substituted endo-3-acetoxy-endo-5-acetoxymethyl-7-oxabicyclo[2.2.1]heptane compounds.
A Convenient Method for the Preparation of Highly Pure t-Alkyl Bromides and Iodides
Authors: Masada Hiromitsu , Murotani Yoshiharu
Published: July 2006

Highly pure (99–100%) t-butyl and t-pentyl bromides and iodides, and 3-bromo-3-ethylpentane were readily prepared in 83–95% yields by the reactions of the corresponding alcohols with hydrobromic or hydroiodic acid, using lithium or calcium halide. The metal halides remarkably increased the yield and the purity of the products.
Facile Synthesis of 2,5-Diacylthiophenes. II. The Reaction of Diketo Sulfides with 1,2-Diketones
Authors: Miyahara Yuji , Inazu Takahiko , Yoshino Tamotsu
Published: July 2006

The base-catalyzed reaction of diketosulfides (RCOCH2)2S (R=phenyl, p-tolyl) with biacetyl or benzil have provided high yields of 2,5-diacyltetrahydrothiophene-3,4-diol derivatives rather than the expected 2,5-diacylthiophenes. The diols have been transformed cleanly into the corresponding 2,5-diacylthiophenes by treatment with thionyl chloride-pyridine. In contrast, the reaction of the diketo sulfide (R=p-tolyl) with phenylglyoxal afforded a 2,5-diacylthiophene directly in good yield.
The Kinetics of the Darzens Reaction of p-Substituted Benzaldehydes and Phenacyl Chloride
Authors: Bansal Raj Kumar , Sethi Kanta
Published: July 2006

The rate constants for the base-catalyzed Darzens reaction of p-substituted benzaldehydes and phenacyl chloride have been measured at two temperatures in aqueous dioxane. Enthalpies and entropies of activation have been evaluated. The reactivity of the p-substituted benzaldehydes was found to follow the order p-NO2>p-Cl>p-Br>H>p-CH3>p-OCH3. The kinetic data can be correlated with ρ values according to the Hammett equation.
Synthetic Inorganic Ion-exchange Materials. XXVI. Ion-exchange Properties of Crystalline Antimonic(V) Acid towards Noble Metals in Nitric Acid Media
Authors: Abe Mitsuo , Akimoto Mitsuo
Published: July 2006

A study of the distribution coefficients on crystalline antimonic(V) acid (C-SbA) shows an unusual affinity series {Pt(IV)<Au(III)<Pd(II)<<Hg(I), Hg(II), Ag(I)} for microamounts of noble metal ions in nitric acid solution, as compared with ion-exchange resins in strong acid type. Extremely high adsorptive properties are found on the exchange system of Hg(II) and Ag(I), even in relatively high concentrations of nitric acid solution. The ion-exchange studies for macroamounts indicate that a solid solution forms for the system of the Ag(I) ions and hydrogen ions in C-SbA, while two solid phases are presented for the system of Hg(II) ions and hydrogen ions.
The Oxidation of (E)-α-Phenylcinnamic Acids with Manganese(III) Acetate
Authors: Oishi Kazuki , Kurosawa Kazu
Published: July 2006

The oxidation of eight (E)-α-phenylcinnamic acids with manganese(III) acetate in boiling acetic acid containing acetic anhydride gave 3-phenylcoumarins, 3-phenyl-l-oxaspiro[4.5]deca-3,7,9-triene-2,6-diones, 2-phenylbenzofurans, 3-(acetoxymethyl)-2-phenylbenzofurans, 3-formyl-2-phenylbenzofuran, 2-acetoxy-2-phenyl-3 (2H)-benzofuranones, (Z)-α-acetoxystilbenes, 2-acetoxy-1,2-diphenylethanones, 5-acetoxy-4,5-diphenyl-2 (5H)-furanones, and diphenylacetylene. The reaction pathways are discussed.
Direct Measurement of the Interaction Energy between Solids and Gases. V. Change of the Differential Heats of Adsorption of Ammonia with Specific Poisoning on Silica–Alumina
Authors: Taniguchi Hitofumi , Masuda Tatsuo , Tsutsumi Kazuo , Takahashi Hiroshi
Published: July 2006

Heats of adsorption of ammonia on specifically poisoned silica–alumina were measured by use of a twin-conduction-type calorimeter in order to elucidate the adsorption energy and acid strength distributions for both Brönsted (hereafter referred to as B) and Lewis (L) acid sites. Infrared spectra of adsorbed pyridine and cumene cracking activity for the poisoned sample were also examined. Sodium alcoholate–alcohol solution was used as the reagent poisoning only B sites. The use of sodium 2-propanolate–2-propanole dilute solution of which sodium contents was approximately equal to the expected amount of proton on silica–alumina surface caused a large portion of B sites to be poisoned without the decrease in the number of L sites. The following conclusions could be drawn from the experimental results that i) above 115 kJ/mol of the differential heat of adsorption of ammonia no B acid sites were present but only L acid sites, and ii) B acid sites existed chiefly in the vicinity of the adsorption energy distribution of 110 kJ/mol.
Photoacoustic Spectrometry of Solid Samples. III. Microdetermination of Mercury as Hg Diphenylcarbazone Complex
Authors: Kawamoto Seiji , Yokoyama Yu , Ikeda Shigero
Published: July 2006

Photoacoustic spectrometry was applied to the determination of michroamount of Hg diphenylcarbazone complex. The photoacoustic spectrum and diffuse reflectance spectrum almost agree with each other, showing an absorption maximum at 560 nm, as in the absorption spectrum of the complex in benzene solution. Determination of Hg was performed by measuring the intensity of photoacoustic signal at 560 nm. The normalized signal intensity increased linearly with the amount of mercury ion up to 100 ng, deviating from linear relationship downwards above 100 ng. The photoacoustic signal saturation caused by strong absorption of radiation was investigated.
A 13C NMR and CNDO/2 Calculation Study of the Transannular Interaction in [2.2]Cyclophanes
Authors: Tokita Kazushi , Takemura Tetsuo , Kondo Shoichi , Mori Nobuo
Published: July 2006

The relationships between the aryl carbon chemical shifts and the CNDO/2 electron densities for several [2.2]cyclophanes are reported. Plots of the chemical shifts against the excess total electron densities indicate additional downfield shifts of 6–9 ppm on the average for those aryl carbons that are in close proximity to other aryl carbons. A plot of the 13C shielding constant, calculated using the Karplus-Pople theory, against the chemical shift shows a downfield shift of a similar magnitude for the proximate carbons relative to the others. It is found that this difference can be essentially eliminated simply by adjusting the ΔE parameter in the Karplus-Pople equation from 10.0 eV to 9.7 eV for the proximate carbon atoms.
The Synthesis and Cation-complexing Ability of Alkyl Crown Ethers
Authors: Mizuno Tadashi , Nakatsuji Yohji , Yanagida Shozo , Okahara Mitsuo
Published: July 2006

Alkyl-15-crown-5 and alkyl-12-crown-4 were prepared via polyethylene glycol β-haloalkyl ethers in two steps from terminal olefins, and their complexing ability with cations of alkali and alkaline earth metals was measured by using 1H NMR; it was found to be almost identified with that of the corresponding unsubstituted crown ether. A new type of alkyl crown ether with a chloro substituent could also be synthesized according to this method.
Photochemical Reactions of Aromatic Compounds. XXXIII. Photoreactions of 1-Cyanonaphthalene with Indene in Various Solvents
Authors: Yasuda Masahide , Pac Chyongjin , Sakurai Hiroshi
Published: July 2006

The stereospecific photocycloaddition of 1-cyanonaphthalene to indene occured in cyclohexane, benzene, diethyl ether, tetrahydrofuran, and ethyl acetate, giving the endo head-to-head cycloadduct as the sole 1:1-adduct. The mechanism was discussed in terms of the exciplex intermediacy. In methanol or in acetonitrile in the presence of water, the photoreaction gave the dihydrocycloadduct (8), accompanied by the formation of 2-methoxyindan and 2,2′-dimethoxy-1,1′-biindanyl or 2-indanol and 1-hydroxy-2,2′-biindanyl. In these solvents, the reactions were suggested to be initiated by photochemical electron transfer; the methoxylated or hydroxylated compounds are formed by the nucleophilic attack of methanol or water on the indene cation. Anionic species, including the 1-cyanonaphthalene anion, were suggested to play important roles in the formation of 8.
The Formation and Some Properties of Hydrous Manganese(IV) Oxide
Authors: Narita Eiichi , Okabe Taijiro
Published: July 2006

The properties of two kinds of hydrous manganese(IV) oxides (abbreviated as hydrous MnO2) prepared by the reduction of KMnO4 and by the disproportionation of K2MnO4 in alkaline solutions were investigated by means of chemical analysis, X-ray analysis, IR spectroscopy, wide-line NMR spectroscopy, thermal analysis, magnetic susceptibility measurement, etc. The chemical reactivity of the hydrous MnO2 was also evaluated from the extent of oxidation to K2MnO4 by the reaction with an alkaline KMnO4 solution at 80 °C. The properties and reactivity of the hydrous MnO2 predominantly depended on the pH of the suspensions. At a pH 8 or higher, amorphous ternary compounds of manganese(IV) oxide with an approximate composition of K2O·4MnOx·4H2O (x=1.97–2.00) were formed. The IR spectra and wide-line NMR spectra showed that the chemically bound water was in two different forms. The hydrous MnO2 had the greater chemical reactivity, being easily soluble as manganate(VI) ions by the reaction described above. The contents of the chemically bound water and alkali in the hydrous MnO2 decreased with a decrease in the pH of the suspensions and upon the acid-treatment of the precipitates. This variation in the chemical composition caused a decrease in the reactivity and a marked variation in the thermal behavior. The structure of the hydrous MnO2 was discussed on the basis of findings regarding the magnetic susceptibility and its temperature dependence.
Complexation of Arenediazonium Ions with a Macrocyclic Polyether. The Stability Constants for the Complexes
Authors: Hashida Yoji , Matsui Kohji
Published: July 2006

The stability constants for 18-crown-6 complexes with arenediazonium salts have been determined spectrophotometrically. The Hammett plot for m- and p-substituted benzenediazonium salts showed good correlation with a reaction constant 0.98 in methanol. The solvent effect on the stability of the complexes has been discussed.
A New Catalytic System for the Preparation of Chromanols
Authors: Tachibana Yoji
Published: July 2006

In the presence of the cation exchange resin complexes of metal ions, hydroquinone, resorcinol, and catechol reacted with phytyl chloride to give chromanols in good yields. The enhanced activity of the catalysts compared with the corresponding metal halides has been ascribed to the participation of the sulfonyl group in the abstraction of the proton on the benzene ring or the hydroxyl group. The catalysts were recycled several times with little loss of activity.
Stereochemical Control Exerted by Methoxyl Group on the Diiodomethane–Copper Methylenation of Cyclic Olefins Containing Methoxyl Group
Authors: Kawabata Nariyoshi , Ikeda Naoki
Published: July 2006

In the diiodomethane–copper methylenation of 3- and 4-methoxycyclopentenes and 3-methoxycyclohexene, the cis isomers of the cyclopropane derivatives predominated over the corresponding trans isomers, the trans isomer of cyclopropane derivatives being predominantly obtained from 3-methoxycyclooctene.
Quaternary Ammonium Periodate as a New Oxidizing Agent
Authors: Inomata Katsuhiko , Nakayama Yukiharu , Kotake Hiroshi
Published: July 2006

Quaternary ammonium periodate has been found to be a useful oxidizing agent to convert a 1,2-diol and an olefin to the corresponding carbonyl compound in anhydrous aprotic solvents. The resulting carbonyl compounds have been reacted with alkyllithium to prepare alcohols in one-pot from a 1,2-diol or an olefin.
Photo-induced Reaction of 2-Bromo-3-methoxy-1,4-naphthoquinone with 1,1-Dicyclopropylethylenes
Authors: Maruyama Kazuhiro , Tojo Masahiro , Otsuki Tetsuo
Published: July 2006

2-(2,2-Dicyclopropylethenyl)-3-methoxy-1,4-naphthoquinone was isolated as a major product, accompanied by 2,2-dicyclopropyl-2,3-dihydronaphtho[2,3-b]furan-4,9-dione in the photochemical reaction of 2-bromo-3-methoxy-1,4-naphthoquinone with 1,1-dicyclopropylethylene. An ionic pathway to lead these products was suggested.
Reactions of Aryldiazomethanes with Chloranil
Authors: Oshima Takumi , Nagai Toshikazu
Published: July 2006

The reactions of several aryldiazomethanes (1a: p-tolyl; 1b: phenyl; 1c: p-chlorophenyl) with chloranil gave stilbenes (3) and spiro-oxetanes (4) at 20 °C in tetrahydrofuran or 1,2-dichloroethane. The isomer ratios of 3 were ca. 2 to 3:1 in favor of cis, depending on the solvents and on the substituents of 1. In the case of 4, however, stable trans-isomers were selectively formed. On the other hand, the presence of added CH3OH suppressed the formations of 3 and 4 and, instead, induced redox reactions giving α,α-dimethoxyarylmethanes and tetrachlorohydroquinone (6). In these redox reactions, the acid decompositions of 1 with 6 were also found. However, the presence of CF3CH2OH allowed the formation of considerable amount of 3 and 4, along with the redox products. The mechanism of these reactions will be discussed.
Cyclodehydrogenation of 3-Isopropenyl- and 3-(1-Phenylvinyl)-tropolones to 8H-Cyclohepta[b]furan-8-one Derivatives
Authors: Imafuku Kimiaki , Yamaguchi Kazuko , Matsumura Hisashi
Published: July 2006

3-(1-Phenylvinyl)tropolone (3b) was prepared by the hydrolysis of cycloadducts of 6-methyl-6-phenylfulvene with dichloroketene. 3-Isopropenyltropolone and 3b were treated with 2,3-dichloro-5,6-dicyano-p-benzoquinone or performic acid to give 3-methyl- and 3-phenyl-8H-cyclohepta[b]furan-8-one, respectively. Reaction of 3b with hydrazoic acid afforded an unexpected 3-acetyltropolone.
Optical Resolutions and Configurations of Benzylmethylphenylsilylmethylamine and Its Derivatives
Authors: Terunuma Daiyo , Murakami Katsutoshi , Kokubo Masanori , Senda Kazuhisa , Nohira Hiroyuki
Published: July 2006

New optically active α-amino organosilanes, such as benzylmethylphenylsilylmethylamine, benzylmethyltolylsilylmethylamines, and anisylbenzylmethylsilylmethylamines, were obtained by the fractional crystallization of the salts of the amines and (+)-tartaric acid. Benzylmethylphenylsilylmethylamine was converted into benzylmethyl-1-naphthylphenylsilane, of which the configuration had been known. From these observations, it was found that benzylmethylphenylsilylmethylamine, benzylmethylphenylsilane, and benzylmethoxymethylphenylsilane had S(+), S(−), and S(+) configurations respectively.
The Study of Surfactant-Alcohol Mixed Micelles Using Conductance, Viscosity, and Electromotive Force Measurements
Authors: Tominaga Toshihiro , Stem Theodore B , Evans D Fennell
Published: July 2006

Conductance, viscosity, and EMF measurements were used to characterize solutions containing surfactant-alcohol micelles. The materials studied included sodium dodecyl sulfate (SDS), sodium octyl sulfate (SOS), decyltrimethylammonium bromide (DTAB), hexadecyltrimethylammonium bromide (CTAB) and the alcohols 1-pentanol through 1-octanol. The addition of alcohols caused the conductance of a 2% SDS solution to increase, and of a 3% solution of DTAB and of a 7% solution of SOS to decrease. CTAB showed both increases and decreases upon addition of alcohol. The EMF measurements permitted the concentration of free surfactant monomer and of unbound counterion in equilibrium with the micelle to be determined. When combined with the viscosity data, the change in conductance upon addition of alcohol can be interpreted in terms of changes in micellar shape and in the concentration of involved ions.
Polyelectrolyte Complexes of Chitosan with Sodium Carboxymethylcellulose
Authors: Fukuda Hiroshi
Published: July 2006

A new water-insoluble precipitate was obtained by mixing chitosan with sodium carboxymethylcellulose, an anti-thrombogenic agent. The mole ratio of N/COO− in the polyelectrolyte complexes was estimated to be 0.3935–0.9071. It was found that pH, mole ratio of N/Na in the reaction mixture and the order of mixing play an important role in determining the composition ratio of N/COO−. In order to clarify the relationship between the molecular conformation of the polyelectrolyte complexes and their properties, IR spectroscopic studies, elementary analyses, color reaction with Toluidine Blue, studies on solubility and blood clotting test in vitro were performed. The polyelectrolyte complex, prepared at higher pH, differed from that prepared at lower pH, particularly in the density of –COOH group site. These results were interpreted in terms of the variation in the degree of electrolytic dissociation of the weak polyelectrolytes, caused by pH change. All the polyelectrolyte complexes revealed clot-inhibition in vitro. The clot-inhibiting behavior seems to be due to the clot-inhibiting surface of the polyelectrolyte complex, not to the elution of the activity from the surface.
Dielectric Properties of the Hydrogen-bonded Liquids. Steric Effects on Dielectric Properties in Glycerol and Acetylated Glycerols
Authors: Ikada Eiji , Yamamoto Kousaku , Ashida Michio
Published: July 2006

The dielectric constant and the dielectric loss of a monohydroxy molecule (glycerol diacetate) and a dihydroxy molecule (glycerol monoacetate) in the pure liquid state were measured over the frequency range from 23 Hz to 3 MHz in order to elucidate the relation between the steric effects of the acetoxyl group and the dielectric properties of alcohols. For a better understanding, the results of this work were discussed together with those of glycerol and glycerol triacetate. The static dielectric constants decrease in the order of glycerol, glycerol monoacetate, glycerol diacetate, and glycerol triacetate. This order agrees with the order of the decreasing number of hydroxyl groups per molecule. On the other hand, the four curves of a temperature variation of the relaxation times almost form one curve, although the molecular weights and interaction, which are important factors for the determination of relaxation times, differ greatly among the four molecules. Accordingly, it is concluded that the decrease in molecular weight due to the replacement of the acetyl group CH3CO by a hydrogen atom counteracts the enhanced molecular interaction due to the increased OH···O hydrogen bonds. The experimental Cole-Cole arcs of the complex dielectric constants were well represented by the calculated curve of the Davidson-Cole empirical equation, for glycerol mono- and diacetate as well as for glycerol.
STUDIES ON THE ASYMMETRIC OXIDATION. PART II
Authors: Shibata Yuji , Tanaka Yasuo , Goda Shiro
Published: July 2006

The Catalytic oxidation of d-catechin by d- and l- [Co en2NH3Cl]Br2 was studied. The course of these oxidation reactions were observed in two different ways: one of the methods was the measurements of rotation changes of solutions containing d-catechin and d- or l-cobaltic complex salt, and the other was the determenations of oxygen quantities absorbed by those solutions during the oxidation reactions. In both cases we could confirm that the oxidation takes place always asymmetrically, d-complex salt oxidising d-catechin more rapidly than l-complex salt.

Further we studied the oxidation of d-catechin by racemic [Co en2NH3Cl]Br2 and could confirm that the oxidation in this case goes on very similarly with the system of (d-catechin +l-complex salt), instead of taking an average course of those shown respectively by d- and l-complex salts. Concerning to the cause of this result, it was discussed from the point of view of natural enzyme actions.
REACTION BETWEEN TRIMETHYLTIN HYDROXIDE AND METHYLIODIDE
Authors: Harada Taichi
Published: July 2006

The reaction between trimethyltin hydroxide and methyliodide was studied. The compound formed from the mixture was identical to the compound formed from trimethyltin hydroxide and trimethyltin iodide having the formula ((CH3)3Sn)3OX, H2O.

The conductance of the compound was studied. The results indicate that the compound appears to be a salt.
ON THE RATE OF SOLUTION OF OXYGEN INTO WATER. PART VI. THE RATE OF ABSORPTION OF OXYGEN BY SODIUM SULPHITE SOLUTION
Authors: Miyamoto Susumu , Kaya Tetsuo
Published: July 2006

(1) The rate of solution of oxygen into sodium sulphite solution of various concentrations was observed by the measurements of the decrease of the volume of gas phase at constant temperature and pressure.

(2) At low concentrations of sodium sulphite solution, the rate of solution of oxygen increases as the concentration of sodium sulphite increases. At middle concentrations, the rate of solution is maximum and independent of the concentration of sodium sulphite.

At high concentrations the rate of solution decreases with the increase of the concentration of sodium sulphite.

(3) A theoretical interpretation on the results of the present experiments was given.
STUDIES ON THE REACTIONS BETWEEN GAS AND SOLID. PART I. VELOCITY OF ABSORPTION OF MOISTURE BY QUICKLIME
Authors: Aono Takeo
Published: July 2006

(1) From the experimental study, it has been found that the mechanism of absorption of moisture by quicklime can be explained as follows: free CaO absorbs moisture to form Ca(OH)2, the velocity of which being proportional to the humidity, and the Ca(OH)2 formed, getting off from the mother CaO in fine powders, and swelling in its volume, quickly absorbs moisture,the amount of which being proportional to the amount of Ca(OH)2 formed.

(2) The general equation of the velocity of the increase of weight at constant temperature has been given as (Remark: Graphics omitted.)

(3) The effect of temperature elevation has also been studied.
STUDIES ON THE REACTIONS BETWEEN GAS AND SOLID. PART II. ABSORPTION OF CO2 BY CaO AND Ca(OH)2
Authors: Aono Takeo
Published: July 2006

(1) It was determened experimentally that the velocity of absorption of CO2 by Ca(OH)2 is proportional to the concentration of CO2 (or partial pressure of CO2) in the air, and to the absorbing capacity of the substance: (Remark: Graphics omitted.) (2) For the change of weight due to the absorption of dry CO2 by dry Ca(OH)2 the following equation was proposed (Remark: Graphics omitted.) and was also experimentally discussed.
Fuel Mixing Effects on Propagation of Premixed Flames. I. Hydrogen + Carbon Monoxide Flames
Authors: Fukutani Seishiro , Kunioshi Nílson
Published: July 2006

The combustion mechanisms in premixed flames having a mixture of hydrogen and carbon monoxide as the fuel and the stoichiometric amount of air as the oxidizer were investigated by numerical simulation to elucidate the fuel-mixing effects on the burning velocity. Hydrogen and carbon monoxide have similar physical properties and their stoichiometric flames with air are known to propagate through the same type of mechanism, governed by active species diffusion. The flames of the mixed fuel hydrogen+carbon monoxide were found here to have their heat-release rate distributions changing with conformity in shape when the fuel composition is changed. The burning velocity was found to vary almost linearly with the hydrogen content in the fuel. Furthermore, the flux of chemical energy which is carried into low-temperature regions by hydrogen atoms diffusing from the flame front was also found to be roughly proportional to the burning velocity.
Structures and Spectral Properties of Some Bis(carboxylato)copper(II)-Pyrazole Complexes. I. Preparation of Bis(trifluoroacetato)tetrakis(pyrazole)copper(II)
Authors: Kogane Tamizo , Harada Kazumasa , Umehara Michiko , Hirota Reiko , Nakahara Masayoshi
Published: July 2006

The preparation of several kinds of [Cu(tfa)2(Hpzl)4] (Htfa = trifluoroacetic acid; Hpzl = 1H-pyrazoles) by stoichiometric reactions of [Cu(hfac)2] (Hhfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione) with a pyrazole in petroleum ether is reported. As isolable intermediate of this reaction, [Cu(hfac)2(Hpzl)4] was obtained in some cases. The structure of [Cu(tfa)2(4-Hmpz)4] (1e) (4-Hmpz = 4-methyl-1H-pyrazole) has been determined by X-ray analysis. The structures of other [Cu(tfa)2(Hpzl)4] are estimated on the basis of their IR spectra.
Formation of AOT Reversed Micelles and W/O Microemulsions
Authors: Kawai Takeshi , Hamada Kaoru , Shindo Naoaki , Kon-no Kijiro
Published: July 2006

The dependence of limiting amounts of solubilized water upon the concentration of sodium 1,2-bis(2-ethylhexyloxycarbonyl)ethanesulfonate (AOT) in apolar solvents was measured by the Karl-Fischer method at 30 °C. In the solubilization regions, two or three states of water, i.e., water bound directly to ionic head groups of AOT and water bound to the hydrated ionic groups or bulk-like water, were found to exist from NMR, ESR, fluorescence, and near infrared spectroscopic measurements. These types of water were related to the formation of reversed and swollen micelles or W/O microemulsions.
Mutual Separation Characteristics and Mechanism for Lanthanoid Elements via Gas Phase Complexes with Alkaline Metal and/or Aluminium Chlorides
Authors: Murase Kuniaki , Shinozaki Kiyoshi , Machida Ken-ichi , Adachi Gin-ya
Published: July 2006

Mutual separations between mixed lanthanoid chlorides, LnCl3 (Ln = Pr and Nd), were performed using a chemical-vapor transporting method via gaseous complexes with a series of alkaline metal chlorides (ACl). The resulting separation factor depended slightly on the alkaline metals, indicating a tendency for the factor to increase with the atomic number; good separation characteristics were observed for gaseous complexes with KCl and RbCl. For complexes in ternary systems, LnCl3–ACl–AlCl3, the codeposition of ACl with LnCl3, which took place in the binary system, LnCl3–ACl, was depressed and LnCl3 was obtained in a form free from the used complex formers.
Effect of Ionizable and Non-Ionizable Surfactants on the Polarographic Reduction of Some Metal Ions
Authors: Ismail Mohamed Ismail
Published: July 2006

The effect of ionizable and non-ionizable surfactants was studied on the electrode kinetics of various metal ions such as TI(I), Pb(II), Sb(III), U(VI), Bi(III), Cu(II), Cd(II), In(III), Cr(III), and Ti(IV) in an acetate medium. The cationic surfactant, dodecylammonium perchlorate (DDAH+), causes a little enhancement effect on most metal ions studied. The non-ionic surfactant, Triton X 100 causes a marked negative shift in E1/2 of all metal ions except Tl(I). The shift in E1/2 can be used for the selective polarographic determination of these metal ions either individually in the presence of TI(I) or simultaneously in a mixture. The anionic surfactant, sodium dodecylsulfate (DDS) forms an electro-inactive complex with In(III). Advantage of this behavior was taken to determine Cd(II) in the presence of In(III). Excellent linear correlations were observed between the limiting current (i1) and the concentration (C) of metal ions.
Spectrophotometric Determination of Trace Amounts of Sulfide Ion Based on Its Catalytic Reduction of Toluidine Blue
Authors: Mousavi Mir Fazlollah , Shamsipur Mojtaba
Published: July 2006

A simple, rapid, and sensitive method has been developed for the determination of trace sulfide (0.28–1.7 μg cm−3) based on its catalytic reduction of Toluidine Blue in the presence of Se(IV). The reaction is monitored spectrophotometrically by measuring the decreasing absorbance of the dyestuff at 628 nm by the fixed time method. The limit of detection is 50 ng cm−3 and the relative standard deviation for 1 μg cm−3 sulfide is 2.4%. The method was applied to the determination of sulfide in spring water.
Mechanism of the Triplet-Sensitized Photolysis of N-(1-Naphthylsulfonyl)-N-phenyl-O-(p-toluoyl)hydroxylamine
Authors: Sakurai Tadamitsu , Nakamura Makoto , Hakii Tsuyoshi , Inoue Hiroyasu
Published: July 2006

The title hydroxylamine (SO2NT) undergoes triplet-sensitized photolysis in the presence of benzophenone (BP) or its derivative to give rearrangement and fragmentation products. Observations of the toluoyloxyl-migrated products, which are not obtained by the triplet-sensitized photolysis of N-(1-naphthoyl)-N-phenyl-O-(p-toluoyl)hydroxylamine (NT), indicate the occurrence of an efficient intersystem crossing of a triplet radical pair initially formed into a singlet radical pair. Internal heavy-atom-like effects of the partially charged sulfonyl sulfur and oxygen atoms are suggested to be responsible for this effective spin inversion. The finding that benzil, both the excited singlet and triplet states of which lie below those of SO2NT, causes a sensitized photolysis of this hydroxylamine to afford the same rearrangement and fragmentation products establishes the fact that a reaction sensitized by BP or its derivative proceeds through a triplet-exciplex intermediate. The effects of the solvent polarity and substituents of BP on the quantum yields for the reaction are discussed.