bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Crystal and Molecular Structure of Chloro-α,β,γ,δ-tetraphenylporphinatocobalt(III)
Authors: Sakurai Tosio , Yamamoto Kiyoko , Naito Hirobumi , Nakamoto Nobuaki 
Published: July 2006

Abstract
The structure of the title compound, C44H28N4CoCl, has been determined by single-crystal X-ray diffraction. The crystals are body-centered tetragonal, with a=b=13.693(2), c=9.701(2) Å, and Z=2. The space group was determined to be I4 from the measurement of the anomalous dispersion effect. The structure was predicted prior to the X-ray analysis from the calculation of the intermolecular van der Waals energy; the result agreed quite well with the experimentally determined structure. A tetragonal pyramidal five coordination with the chlorine atom at the apex was found for the cobalt atom. The cobalt-chlorine distance is 2.149 (6) Å, about 0.1 Å shorter than those found in ordinary octahedral coordinations.
Dehydroannulenes. IV. Synthesis and Properties of 1,14-Di-tert-butyl-5,10-diphenyl-6,8,15,17-tetrakisdehydro[18]annulene. Evidence for the Identity of Diacetylene and Hexapentaene Units in the 18π-Electron System
Authors: Nomoto Tateo , Fukui Kunisuke , Nakagawa Masazumi 
Published: July 2006

Abstract
The synthesis designed to lead to isomeric di-tert-butyldiphenyl-tetrakisdehydro[18]annulenes (VII and XIII) have been performed. It was found that the isomeric tetrakisdehydro[18]annulenes (VII and XIII) are identical in all respects, thus providing chemical evidence for the identity of diacetylene and hexapentaene units incorporated in the aromatic 18π-electron system. Argon laster Raman spectra of VII and XIII exhibited single absorption due to stretching vibration of sp-hybridized carbon-carbon bond at 2080 cm−1 indicating equalized nature of acetylenic and cumulenic linkages in the aromatic dehydroannulene system.
Preparation and Ligand Isotopic Exchange of Tris(acetylacetonato)tin(IV) Perchlorate in Acetonitrile
Authors: Nagasawa Akira , Saito Kazuo 
Published: July 2006

Abstract
Tris(acetylacetonato)tin(IV) perchlorate [Sn(acac)3]ClO4 was prepared in crystalline state in acetylacetone (Hacac) and its structure was verified. It is stable in dehydrated acetonitrile (AN) at room temperature. It undergoes hydrolysis in the presence of a large amount of water (e.g., 10−4 mol dm−3 complex against 10−1 mol dm−3 water) in two steps: The first, fast step gives a product [Sn(acac)2(OH)(H2O)]ClO4, which slowly undergoes further hydrolysis or polymerization to give eventually a gelatinous precipitate. The ligand isotopic exchange with Hacac[14C] can be measured in \simeq10−2 mol dm−3 complex solution in AN containing 0.03–0.12 mol dm−3 water below −20 °C. The rate is independent of free Hacac concentration. The dependence of the rates of the hydrolysis and the ligand isotopic exchange on water concentration is expressed by: rate=A[complex][H2O]2/(1+B[H2O]), where the A values are 0.15 and 0.30 dm6 mol−2 s−1 at −20 °C, ΔH\eweq and ΔS\eweq being (50±8) and (36±20) kJ mol−1, and (−60±20) and (111±40) J mol−1K−1, respectively. There seems to be a common rate-determining step in which one acac− ligand dissociates with the action of water. The intermediate gives rapidly the original complex in the presence of excess Hacac. Otherwise it undergoes further hydrolysis in the presence of an over-whelming amount of water. The large ionic radius of tin(IV) should be responsible for the rapid water substitution as compared with the corresponding octahedral silicon(IV) and germanium(IV).
Preparation and Properties of 7-Formyl-8-hydroxy-5-quinolinesulfonic Acid
Authors: Matsumura Konomu , Sasaki Shin-ichi , Tada Eiko 
Published: July 2006

Abstract
8-Hydroxy-5-quinolinesulfonic acid (I), on condensation with formaldehyde in aqueous ammonia, produced 8-hydroxy-7-hydroxymethyl-5-quinolinesulfonic acid (IV), which, on oxidation with manganese (IV) oxide, gave 7-formyl-8-hydroxy-5-quinolinesulfonic acid (V). On treatment with boiling 6 M hydrochloric acid, V produced bis[α-hydroxy-(8-hydroxy-5-sulfo-7-quinolyl)methyl] ether (VIII).
The Finkelstein Reaction in Acetonitrile–Glycol Mixtures. An Approach by a Concurrent Monodentate and Bidentate Solvation Model of the Halide Ion
Authors: Kondo Yasuhiko , Tanaka Kazuo , Tokura Niichiro 
Published: July 2006

Abstract
The rate constant of the reaction of methyl iodide with the bromide ion showed a characteristic dependence on the composition of solvent mixtures. In five solvent mixtures, i.e., acetonitrile–ethylene glycol, –1,2-propanediol, –1,3-butanediol, –1,4-butanediol, and –2,3-butanediol, its dependence was fairly well reproduced by the theoretical equations derived on the basis of the concept of the concurrent monodentate and bidentate solvation of the halide ion by glycol. In contrast, the rate constants in acetonitrile–diethylene glycol and –triethylene glycol mixtures were better reproduced by the modified theoretical equations allowing for a self-association of glycol.
Synthesis of 2-Amino-2,3-dideoxy-l-ribohexose
Authors: Sano Hiroshi , Tsuchiya Tsutomu , Ban Yoshihiro , Umezawa Sumio 
Published: July 2006

Abstract
2-Amino-2,3-dideoxy-l-glucose (1) was synthesized from 2-amino-2-deoxy-l-glucose (2). The synthesis was achieved without protection of the anomeric hydroxyl group throughout the reaction sequence. The masked derivative (9) of 1 was prepared from 2 by sequential N-methoxycarbonylation, benzylidene acetal formation, mesylation, displacement with iodide, and hydrogenolysis. Alkaline hydrolysis of the debenzylidenated product (10) led to ring contraction and yielded the 1,2-oxazolidinone derivative (11) of a furanose. Acidic hydrolysis of 11 underwent ring expansion and successfully gave 1.
Hetera-p-carbophane. VIII. The Change in Binding Sites of NMR Shift Reagents in Polyoxadioxo[n]paracyclophanes and Their Open-chain Analogs
Authors: Sakamoto Kazuhiko , Oki Michinori 
Published: July 2006

Abstract
A series of polyoxadioxo[n]paracyclophanes were prepared by condensation of polyethylene glycols with the corresponding 2,5-disubstituted p-phenylenediacetyl dichlorides under high dilution conditions. 1H NMR spectra of these compounds were recorded in the presence and absence of lanthanoid shift reagents and the results are compared with those of the open-chain analogs. The change in binding sites of the shift reagents is observed as the number of ethylenedioxy units increases, and the result is discussed from the standpoint of electronic and steric effects.
N-Halogen Compounds of Cyanamide Derivatives. VII. The Preparation and Amidination of 5-Ethoxy-Δ4-1,2,4-thiadiazolines
Authors: Fuchigami Toshio , Nonaka Tsutomu , Odo Keijiro 
Published: July 2006

Abstract
2-Methoxycarbonimidoyl and 2-amidino-3-imino-5-ethoxy-Δ4-1,2,4-thiadiazolines (I and II) were prepared by the reaction of potassium ethoxythiocarbonylcyanamide (III) with N-chloro compounds of O-methylisourea and guanidine. Δ4-1,2,4-Thiadiazoline, I reacted with aliphatic amine to give 2-amidino-Δ4,2,4-thiadiazolines and 1,3,5-triazines in the presence of both the free amines and amine hydrochlorides. The ring opening of Δ4-1,2,4-thiadiazoline, which finally results in the formation of 1,3,5-triazine, was found to be catalyzed mainly by a base and also by an acid.
Conformationally Stable 1-Substituted 1-Methyl-4-t-butyl-1-silacyclohexanes, a New Organosilicon System Suitable for Stereochemical Studies
Authors: Sakurai Hideki , Murakami Masashi 
Published: July 2006

Abstract
Ten 1-methyl-4-t-butyl-1-silacyclohexyl derivatives (C10H21Si–X, X=H, Cl, OCH(CH3)2, OCH3, OC(CH3)3, C6H5, p-Br–C6H4, p-Cl–C6H4, Si(CH3)2H, F) were synthesized and separated into conformationally stable cis and trans isomers. The stereochemistry of these compounds has been determined on the basis of NMR and GLC. They were found to behave stereochemically like acyclic optically active silanes.
Syntheses of 2-Amino-2,3-dideoxy-l- and -d-Ribohexose by Utilizing an O→N Acetyl Migration
Authors: Yamasaki Tetsuro , Kubota Yutaka , Tsuchiya Tsutomu , Umezawa Sumio 
Published: July 2006

Abstract
2-Amino-2,3-dideoxy-l- and -d-ribohexose (1l and 1d) were synthesized from 2-amino-2-deoxy-l- and -d-glucose, respectively, through a reaction sequence which involves 3-O→2-N acetyl migration of methyl 3,4,6-tri-O-acetyl-2-amino-2-deoxy-β-l- and -d-glucopyranoside (3l and 3d). A preparative method of methyl 4,6-di-O-acetyl-2-amino-2-deoxy-β-d-glucopyranoside (11d) is given.
Aminocyclitols. 34. Synthesis of Inosadiamine-1,4 Derivatives
Authors: Tadano Kinnichi , Shiratori Takaaki , Suami Tetsuo 
Published: July 2006

Abstract
Three new inosadiamine-1,4 derivatives have been prepared by nitromethane cyclization of a dialdehyde obtained by periodate oxidation of 1,4-di-O-methyl-(l,2,3,4,5/0)-5-acetamido-l,2,3,4-cyclopentanetetrol. The cyclization product was catalytically hydrogenated and subsequently acetylated to give three inosadiamine derivatives. Their structures were established by PMR spectra as myo-2,5, epi-1,4, and cis-inosadiamine-1,4 derivatives.
Reaction of Dimethylphenacylsulfonium Bromide with N-Nitrosoacetarylamides and Reactions of the Products with Nucleophiles
Authors: Shawali A Sami , Abdelhamid A Osman 
Published: July 2006

Abstract
The azo coupling of dimethylphenacylsulfonium bromides (I) with N-nitrosoacetanilides in nonaqueous solvents, and with diazotized aniline in aqueous media gave 2-bromophenylglyoxal 2-arylhydrazones (V) and the tetrazine (VI), respectively. V reacted with nucleophiles displacing the bromide. Treatment of V with bases gave VI via benzoylphenylnitrilimine (X). 1,3-Dipolar cycloadditions of X onto ethyl acrylate and acrylonitrile afforded the expected cycloadducts. The mechanisms of the reactions are outlined.
Micellar Activation of Nucleophilic Reactivity of Coenzyme A and Glutathione toward p-Nitrophenyl Acetate
Authors: Shinkai Seiji , Kunitake Toyoki 
Published: July 2006

Abstract
The reaction of coenzyme A(CoASH) and glutathione (GSH) with p-nitrophenyl acetate was studied in aqueous media at 30 °C. The reaction is highly accelerated in the presence of hydrophobic aggregates such as hydrophobic oligocations and CTABr micelles. Nonionic and anionic micelles were ineffective. The pKa of CoASH is lowered by 0.5 pKa unit in 2 mM of CTABr, while that of GSH is hardly affected. The second-order rate constant for CoASH is improved (290-fold) more than that of GSH (100-fold), relative to the nonmicellar system. Enhanced reactivities are efficiently suppressed by addition of KCl. These results are the first example of the marked activation of sulfhydryl coenzymes by the micellar microenvironment, and explicable by the concept of hydrophobic ion pairs: the coenzymes are bound onto the cationic micelle and the thiol anions form ion pairs with surfactant cations at the relatively hydrophobic environment of the micelle.
The N-Alkylation of Xanthine Derivatives with Trialkyl Phosphates
Authors: Tanabe Toshizumi , Yamauchi Kiyoshi , Kinoshita Masayoshi 
Published: July 2006

Abstract
The N-alkylation of xanthine, theophylline, and theobromine with trimethyl, triethyl, and triallyl phosphates in a weak alkaline aqueous solution is described. Especially, trimethyl phosphate converted these heterocycles to the corresponding N-methyl derivatives in good yields.
A Simple Method for the Synthesis of Lignan Skeleton. Syntheses of (±)-Parabenzlactone and (±)-Hinokinin
Authors: Asano Yuzo , Kamikawa Tadao , Tokoroyama Takashi 
Published: July 2006

Abstract
The reaction of 2-aryl-2-lithio-l,3-dithianes with 2-butenolide followed by quenching with benzyl halides gave lignan skeleton in fairly good yield.
Sulfoxonium Ylide Chemistry. VII. Reductive Cleavage of Dimethylsulfoxonium Allylides
Authors: Ide Junya , Kishida Yukichi 
Published: July 2006

Abstract
Reductive cleavage of dimethylsulfoxonium allylides with zinc in acetic acid or by hydrogenation over platinum at high pressure (120 atm) has been investigated. Reduction of dimethylsulfoxonium 3-ethoxycarbonyl-2-phenylallylide (1) with zinc gave predominantly ethyl 3-phenyl-3-butenoate (2) together with ethyl (E)-3-phenyl-2-butenoate (3) (90: 10). However, under the more acidic conditions (pH 2), 3 was the exclusive product. Hydrogenation of 1 over platinum afforded a mixture of 3 and ethyl 3-phenylbutanoate (4). Reduction of dimethylsulfoxonium 3-ethoxycarbonyl-2-phenyl-1-(phenylcarbamoyl)allylide (6) either with zinc or by hydrogenation gave ethyl (Z)-3-phenyl-4-phenylcarbamoyl-2-butenoate (7). Hydrogenation of dimethylsulfoxonium 1-benzoyl-3-ethoxycarbonyl-2-phenylallylide (9) at room temperature provided ethyl (Z)-3,5-diphenyl-5-oxo-2-pentenoate (10) and 4,6-diphenyl-2-pyrone (11), and at 80°C 11 and ethyl 3,5-diphenyl-5-oxopentanoate (12).
Studies on the Reacions of Bis(acetylacetonato)platinum(II) with Lewis Bases. II. Reaction with Pyridine Leading to Complexes Containing Uni- and Bis-Carbon Bonded Acetylacetonato Ligand(s).
Authors: Ito Takashi , Kiriyama Takashi , Nakamura Yoshiyuki , Yamamoto Akio 
Published: July 2006

Abstract
Heating a pyridine solution of [Pt(acac)2] (acac=2,4-pentanedionato-O,O′) at 100°C afforded central C-bonded complexes, [Pt(acac)(γ-acac)py], 1, and [Pt(γ-acac)2py2], 2 (γ-acac=2,4-pentanedionato-C3). Complexes 1 and 2 were isolated and characterized by means of elemental analysis, infrared and 1H- and 13C-NMR spectroscopy. Heating 1 in pyridine yielded 2, and conversely, heating 2 in CDCl3 yielded 1. All these reactions were monitored by 1H-NMR spectroscopy and were found to obey the first-order rate law. From the rate constants at various temperatures, activation parameters were calculated for each reaction. Existence of isokinetic relationship among these three reactions suggests the presence of a common reaction intermediate. Observation of the variable temperature 1H-NMR spectra of [Pd(acac)(γ-acac)py] in pyridine suggests that the activated intermediate may be a species having an oxygen-bonded unidentate acac ligand (“dangling” enolate ligand).
The Constitution of NaPO3–Cr2O3 Melts
Authors: Watanabe Makoto , Sato Shoji , Saito Hajime 
Published: July 2006

Abstract
Glassy and crystalline thermal products were made by heating a mixture of sodium metaphosphate glass and chromium(III) oxide with P/Cr ratios in the range from 1.0 to 300 at 1000 °C for 3 h in a platinum crucible and by then rapidly quenching the resulting melt. The crystalline substances were present in the products with P/Cr ratios smaller than 50 and were, except for chromium(III) oxide, an unknown substance and chromium(III) tripolyphosphate. The colorimetric determination and the measurement of the average chain length of polyphosphate anions present in the water-soluble parts of the products with P/Cr ratios larger than 50 showed that chromium(III) oxide reacts with sodium metaphosphate glass to make Cr–O–P linkages. Assuming that the glass has P–O–P, P-O−, Cr–O–P, and Cr–O− linkages, a theoretical treatment of the degree of polymerization of condensed phosphates were made and compared with the data. It was concluded that the most reasonable chemical structure of the glassy thermal products of the NaPO3–Cr2O3 system is Cr(OP)3.
Synthesis of Dihalogenobis(2-pyridinethiolato)tin(IV) by the Oxidative Addition of Bisulfide to Tin(II) Halides—Consideration on the Coordination Structure
Authors: Masaki Mitsuo , Matsunami Satoshi 
Published: July 2006

Abstract
The reaction of di-2-pyridyl disulfide with tin(II) halides was found to give dihalogenobis(2-pyridinethiolato)-tin(IV). The oxidative addition reaction was successfully extended to the preparation of other dihalogenodi-thiolatotin(IV) complexes. Dichlorobis(2-pyridinethiolato)tin(IV) was also prepared by the reaction of 2(1H)-pyridinethione with tin(IV) chloride and proposed to be a monomeric, octahedral complex with a four-membered (Sn, S, C, and N) chelate ring from its molecular weight and IR spectral data. Dichlorobis(2-quinolinethiolato)tin(IV) could be isolated similarly as a stable complex. However, attempts to isolate the dichlorodithiolatotin(IV) in which an intramolecular chelation seems hardly possible were unsuccessful. The great stability of bis(2-pyridinethiolato)- and bis(2-quinolinethiolato)-dihalogenotin(IV) could be ascribed to the intramolecular four-membered chelate ring formation for the six-coordination of tin atom.
Dielectric Behavior of N-Methylacetamide
Authors: Itoh Koichi , Sato Hiroshi , Takahashi Hiroaki , Higasi Keniti 
Published: July 2006

Abstract
The dielectric constants and losses of liquid N-methylacetamide were measured in the frequency range 0.356–2.10 GHz at 31.4 °C. The result provides a definitive evidence for the validity of the simple Debye equation for the dielectric relaxation process of liquid N-methylacetamide.
Carbonylation of Dienes and Diols in the Presence of Copper(I) Carbonyl Catalysts
Authors: Souma Yoshie , Iyoda Jun , Sano Hiroshi 
Published: July 2006

Abstract
Dienes and diols having carbon numbers of 6 to 12 reacted with carbon monoxide to give mixtures of lactones, dicarboxylic acids and monocarboxylic acids in the presence of copper(I) carbonyl catalysts at room temperature and at 1 atm of carbon monoxide. Dienes and diols having carbon numbers larger than 10 gave isomers of dicarboxylic acid, the main component of which was tetramethyl-substituted tertiary carboxylic acid. The yield increased for an increase of the carbon number. All starting materials gave mixtures of 1,4- and 1,5-lactones. Larger amounts of the lactones were obtained from diols than from dienes. Cyclic monocarboxylic acid and saturated monocarboxylic acid were obtained by the carbonylation of 1,7-octadiene. The appropriate reaction temperature of the dienes and diols was 0–10 and 20–30 °C respectively.
Layered Compounds. XXXIV. Molecular and Crystal Structure of a Polycyclic Compound from Novel Cycloaddition Reaction of Triple-layered Anthracenophane
Authors: Toyoda Toshihiro , Iwama Akio , Otsubo Tetsuo , Misumi Soichi 
Published: July 2006

Abstract
An unusual Diels-Alder reaction was observed to give intramolecular cycloadducts during the syntheses of triple-layered cyclophanes containing anthracene nucleus. The structure of the product was determined by spectral and X-ray crystal analyses. The crystal is monoclinic, P21/c, with a=15.896, b=8.937, c=18.575 Å, β=120.31°, Z=4. The crystal structure was determined by the direct method using the MULTAN program and refined by the block-diagonal least-squares method to an R index of 0.081. The structure of the molecule is fairly strained.
Note on the Use of Linear Free Energy Relationships in Heterogeneously Catalyzed Reactions
Authors: Kieboom A P G 
Published: July 2006

Abstract
A critical examination of the use of linear free energy relationships in the study of the mechanism of heterogeneously catalyzed reactions is presented in the case of the ruthenium catalyzed hydrogenation of monoalkylbenzenes reported in the literature. It is concluded that the use of both electronic and steric substituent parameters leads to a quite different mechanistic interpretation as compared to the statements made before in the literature on the basis of just the electronic substituent parameter.
Preparation and Circular Dichroism of Cyanoamminebis[(R)-propylenediamine]cobalt(III) Complexes
Authors: Kashiwabara Kazuo , Suzuki Shoichi 
Published: July 2006

Abstract
Three new complexes, trans-, cis-Λ-, and cis-Δ-[Co(CN)(NH3)(R-pn)2]2+(pn=propylenediamine) were prepared. The geometrical structure was determined on the basis of 1H NMR spectra. The optical isomers were characterized from the circular dichroism spectra.
The 13C NMR Spectra of Several 4-Amino-3-penten-2-ones and Their Palladium Complexes
Authors: Senda Yasuhisa , Kasahara Akira , Suzuki Akio , Izumi Taeko 
Published: July 2006

Abstract
A 13C NMR study of several 4-amino-3-penten-2-ones and their palladium chelate complexes is presented. The resonances of the carbonyl carbons of these complexed molecules moved upfield by about 20 ppm relative to the free ligands, while no significant shifts were observed for those of carbons bearing the amino groups.
Sulfoxonium Ylide Chemistry. VI. A Convenient Method for Synthesizing 1-Substituted 4-Phenyl-3-pyrrolin-2-ones
Authors: Ide Junya , Yura Yasuo 
Published: July 2006

Abstract
Synthesis of 1-substituted 4-phenyl-3-pyrrolin-2-ones (2) from dimethylsulfoxonium 3-ethoxycarbonyl-2-phenylallylide (1) and various primary amines is described.
Phase Diagram of the Pyrene-Picryl Chloride System
Authors: Bando Masaki , Matsunaga Yoshio 
Published: July 2006

Abstract
A differential scanning calorimetric study of the pyrene–picryl chloride system has revealed five molecular compounds with mole ratios of 1: 1, 4: 3, 2: 1, 3: 1, and 4: 1 respectively.
Charge-carrier Drift Mobility in Pyrene Single Crystals
Authors: Suzuki Akira , Inokuchi Hiroo , Maruyama Yusei 
Published: July 2006

Abstract
The charge-carrier drift mobility in highly pure pyrene single crystals was measured. Observed values were (3.8±0.1) ×10−3 cm2 V−1 s−1 for electrons and (3.3±0.4) ×10−3 cm2 V−1 s−1 for holes at 345 K. The mobilities increased with the temperature between 333–374 K with an activation energy of 0.43±0.01 eV for electrons.
Observation of the Scale Formed on Nickel in Nitrogen Oxide
Authors: Takasu Yoshio , Maru Shun-ichi , Matsuda Yoshiharu 
Published: July 2006

Abstract
The state of the scale formed on nickel in nitrogen oxide was examined. Its characteristics are summarized as follows: (1) remarkable oxidation of the grain boundary, (2) the formation of a large amount of lattice defects, and (3) unequal oxidation behaviors for the various crystal planes.
Photoreactions of Flavanones
Authors: Nakashima Ruka , Okamoto Kazuaki , Matsuura Teruo 
Published: July 2006

Abstract
On irradiation in benzene, 5,7-dimethyl-4′-methoxyflavanone gave a bis-flavanone V, while in 2-propanol it was largely recovered. Irradiation of 4′-methoxyflavanone in benzene and 2-propanol yielded the corresponding chalcone and pinacols, respectively. 5,7,4′-Trimethoxyflavanone was relatively inert to photolysis in benzene, but gave a complex mixture of products in 2-propanol.
The Photochemical Synthesis of 5-Aryl-7,12-benz[a]anthracenediones from 1,4-Naphthoquinones and 1,1-Diarylethylenes
Authors: Maruyama Kazuhiro , Otsuki Tetsuo , Mitsui Kiichiro 
Published: July 2006

Abstract
By the photolysis of the benzene solution of a variety of 2,3-disubstituted (halogeno, methoxy, and acetoxy) 1,4-naphthoquinones, 1, and 1,1-diarylethylenes, 2, 5-aryl-7,12-benz[a]anthracenediones, 3, are obtained in fairly good yields (22–68%).
The Structure of Hamayne, a New Alkaloid from Crinum asiaticum L. var. japonicum Baker
Authors: Ochi Masamitsu , Otsuki Hitoshi , Nagao Kosho 
Published: July 2006

Abstract
The structure of hamayne isolated from the fruit of Crinum asiaticum L. var. japonicum Baker was established to be O-demethylcrinamine (IV) on the basis of spectral and chemical evidence.
Nature of Oxygen Species Incorporated into Acrylaldehyde in Vapor-Phase Oxidation of Propylene over Supported Copper Catalyst
Authors: Akimoto Masamichi , Akiyama Masao , Echigoya Etsuro 
Published: July 2006

Abstract
The oxidation of propylene with Cu2O as active phase for acrylaldehyde formation gave no acrylaldehyde in contrast to the fully oxidized CuO–SiC. However, CuO–SiC from which adsorbed oxygen species was eliminated gave rise to the formation of a negligible amount of acrylaldehyde. The presence of molecular oxygen species adsorbed on the CuO–SiC was shown by the desorption of oxygen and the isotopic mixing reaction of 16O–18O. The adsorbed oxygen (possibly molecular oxygen species) seems to be necessary as oxygen incorporated into acrylaldehyde. Agreement of the ratio of 18O/16O in acrylaldehyde formed by the oxidation with oxygen containing 18O over Cu216O with that of 18O/16O in the reaction mixture supports the role of adsorbed oxygen species. The presence of O2− over Cu2O during the course of oxidation was confirmed by the formation of furan and maleic anhydride in the co-oxidation with butadiene. The results were discussed in relation to the structure of the catalyst suitable for selective oxidation, the incorporation of oxygen atom via electronegative oxygen species adsorbed being proposed.