bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanisms and Kinetics of the Decomposition of Trioxalatocobaltate(III) in Aqueous Sulfuric Acid
Authors: Kimura Masaru , Sato Toshiro 
Published: July 2006

Abstract
The kinetics of the thermal decomposition of the trioxalatocobaltate(III) complex were studied in a sulfuric acid solution in the absence and in the presence of oxygen from 25 to 40°C. The decomposition of trioxalatocobaltate(III) was described by the equation: -d[Co(C2O4)33−]/dt=(k1+k2[H+])[Co(C2O4)33−]. The values of k1 and k2 were 6×10−6 sec−1 and 1.8×10−5 M−1 sec−1 respectively at 25°C. The values of the activation enthalpy change, ΔH1\eweq and ΔH2\eweq, were 29.7 and 30.0 kcal mol−1 respectively. The values of the activation entropy change, ΔS1\eweq and ΔS2\eweq, were 17.4 and 20.9 eu respectively at 40°C. Although hydrogen peroxide was formed in the presence of oxygen, and although a white precipitate of the polymerized products of acrylonitrile was found in the presence of acrylonitrile, neither oxygen nor acrylonitrile affected the kinetics of the decomposition of trioxalatocobaltate(III). The decomposition of peroxodisulfate was induced by the decompossition of trioxalatocobaltate(III). However, the rate of the decomposition of trioxalatocobaltate(III) was not affected by peroxodisulfate. On the other hand, both copper(II) and iron(III) ions were accelerators of the decompsition of trioxalatocobaltate(III). An anion radical of CO2− was predicted as an intermediate. The reaction mechanisms will be presented to account for these facts.
Preparation and Characterization of Cobalt(III) Complexes with N-Carboxylate Derivatives of l-Prolinate
Authors: Okamoto Ken-ichi , Hidaka Jinsai , Shimura Yoichi 
Published: July 2006

Abstract
Four cobalt(III) complex anions, bis(l-prolinate-N-monopropionato)-, (l-prolinate-N-monoacetato)(imino-diacetato)-, (l-prolinate-N-monopropionato)(iminodiacetato)- and (l-prolinate-N-monoacetato)(l-prolinate-N-monopropionato)cobaltate(III) were synthesized. They were isolated as sodium or potassium salts by ion-exchange column chromatography. These complexes were characterized on the basis of their absorption and circular dichroism spectra in the visible and near ultraviolet regions. All the complexes obtained in solid state have trans(N)-RR or trans(N)-R. configuration. Two geometrical isomers were obtained for (l-prolinate-N-monopropionato)triamminecobalt(III) complexes.
Kinetics and Mechanism of Formation of Monothiocyanato and Mononitrilotriacetato Complexes of Iron(III)
Authors: Funahashi Shigenobu , Adachi Shoji , Tanaka Motoharu 
Published: July 2006

Abstract
Kinetics of the formation of monothiocyanato and mononitrilotriacetato complexes of iron(III) in aqueous solution have been studed by using a stopped-flow technique:
Fe3++SGN−\oversetk1\undersetk−1\ightleftharpoonsFeNCS2+
FeOH2++SCN−\oversetk2\undersetk−2\ightleftharpoonsFeNCS2++OH−
FeOH2++H2nta−\oversetk→Fe(nta)+H+
Rate constants at 25°C and μ=0.5 (NaClO4) are as follows: k=90 M−1 sec−1, k−1=1.6 sec−1, k2=5.1×103M−1sec−1, k−2=10×1013 M−1 sec−1, k=1.0×105 M−1 sec−1. Some discussions are made on the effect of hydroxide ion on the complex formation reactions.
The Cobalt Carbonyl-catalyzed Hydroesterification of Butadiene with Carbon Monoxide and Methanol
Authors: Matsuda Akio 
Published: July 2006

Abstract
The cobalt carbonyl-catalyzed hydromethoxycarbonylation of butadiene is studied. The reaction proceeds in the presence of a pyridine base to give methyl 3-pentenoate. Isoquinoline is found to be a better solvent for the production of methyl 3-pentenoate than pyridine, not only because the yield of the ester is somewhat higher in the presence of isoquinoline than in the presence of pyridine, but also because it is far less volatile than pyridine, so that the product can be easily separated from the solvent and the catalyst by distillation. Also, the hydromethoxycarbonylation of methyl 3-pentenoate under somewhat different conditions is found to give a good yield of dimethyl adipate. The hydroformylation of methyl 3-pentenoate is studied as well. The effect of such a solvent as THF, benzene, and acetonitrile in increasing the selectivity to methyl 5-formylpentanoate is found to increase in this order: acetonitrile&lt;benzene&lt;THF.
The Reaction of β-Amino α,β-Unsaturated Esters with Amines
Authors: Yokoyama Yasukazu , Tai Akira 
Published: July 2006

Abstract
The reactions between amines and 1,4-bis(ethoxycarbonyl)-2,5-bis(alkyl- or arylamino)-1-4-cyclohexadiene(I) and its analogs are studied. The main products are N,N′-disubstituted urea(II) and 1,4-bis(alkyl- or arylamino)-1,4-cyclohexadiene(V) instead of the expected carboxamide. The presence of small amounts of ethyl N-substituted carbamate (III) in the products leads to the conclusion that the reaction proceeds through two successive steps: the nucleophilic attack by an amine upon a carbonyl carbon atom of the ethoxycarbonyl group, with a cleavage of a carbon-carbon bond to give III and V, and the amidation of III in situ, giving II. The rate of the second step is much faster than that of the first step. The formation of II occurs in the compounds with a β-amino α,β-unsaturated carbonyl group.
Solvent Effect on the Free Radical Phenylation with Phenylazotriphenylmethane
Authors: Kobayashi Michio , Minato Hiroshi , Watanabe Nobuko 
Published: July 2006

Abstract
The effect of solvent on free radical phenylation of arenes was studied by using phenylazotriphenylmethane as the source of phenyl radical. Mixtures of two arenes were phenylated in a solvent (CCl4, CH3CN, DMSO, or cyclohexane), and isomer distributions of diaryls produced were determined. The effect of salts (NaNO2, KNO2, NaClO4) was also studied in DMSO. Both the solvent effect and salt effect suggest the contribution of polar structure in the transition states for the formation of phenylcyclohexadienyl radicals.
Dimerization of Isoprene by Palladium-Diphosphine Complex Catalyst
Authors: Takahashi Kuniyuki , Hata Go , Miyake Akihisa 
Published: July 2006

Abstract
Oligomerization of isoprene catalyzed by the PdBr2(Ph2PCH2CH2PPh2)2-PhONa catalyst was studied. The catalyst activity was greatly enhanced by the addition of phenol. Five linear dimers were identified. Distribution of the isomeric dimers was remarkably affected by the molar ratio of phenol to isoprene. The reaction in the presence of a small amount of phenol (phenol/isoprene=1/30) gave 2,7-dimethyl-1,trans-3,7-octatriene derived from a tail-to-tail dimerization almost selectively, while the addition of a large amount of phenol (phenol/isoprene=1/1.5) afforded head-to-head dimers (2-vinyl-5-methyl-1,6-heptadiene and 3,6-dimethyl-1,cis-3,7-octatriene) as main dimers (more than 40% of all the dimers). In a 1:3 ratio of phenol to isoprene the dimers consisted of mainly 2,6-dimethyl-1,trans-3,7-octatriene derived from a head-to-tail dimerization.
Charge-transfer and Proton-transfer in the Formation of Molecular Complexes. IV. Picric Acid Complexes with Benzidine and Its Derivatives
Authors: Saito Gunzi , Matsunaga Yoshio 
Published: July 2006

Abstract
The preparation of picric acid complexes with benzidine, o-tolidine, 3,3′-dichloro-o-tolidine, 3,3′-dibromo-o-tolidine, o-dianisidine, and N,N,N′,N′-tetramethylbenzidine was attempted in the following three solvents: benzene, chloroform, and ethanol. From benzene and chloroform, 3,3′-dibromo-o-tolidine forms a 1 : 1 complex of the charge-transfer type, but the other five diamines give yellow salts formed by means of proton-transfer. Some complexes prepared in ethanol are of an unfamiliar nature. The spectroscopic examination of the 1 : 1 complexes with o-tolidine, o-dianisidine, and tetramethylbenzidine revealed that a half of the diamine molecule acts as a proton-acceptor, while the other half has a charge-transfer interaction with the picrate ion. The simultaneous operation of charge-transfer and proton-transfer interactions was also demonstrated in the black-colored complex with benzidine of a 2 : 1 composition.
Electronic Structures and Spectra of Pyridinyl Hetero Diradicals. Charge-transfer Interaction between Two Different Radicals
Authors: Itoh Michiya 
Published: July 2006

Abstract
Pyridinyl hetero diradicals, Py(Ac)·(CH2)n Py(Car)·, (in which Py(Ac)· and Py(Car)· are 4-CH3OCC5H4N· and 4-CH3OOCC5H4N·, respectively, and n=3, 4, and 5) were obtained. Equilibrium between the open and closed forms in the hetero diradical n=3 was directly observed by temperature dependence of absorption spectra (−ΔH=5.6 kcal and ΔS=10.5 e.u.). Electronic absorption spectroscopy and SCF–CI molecular orbital calculation reveal that the closed form shows a strong charge-transfer band from Py(Car)· to Py(Ac)· moieties. The electronic structure of the hetero diradical was discussed in relation to the electronic interaction between two different radicals.
Spin Trapping by Use of Nitroso-Compounds. VII. β-Fluorine Splitting Constants in Nitroxides
Authors: Terabe Shigeru , Konaka Ryusei 
Published: July 2006

Abstract
Hyperfine splitting constants of β-fluorine atoms in aryl perfluoroalkyl nitroxides, ArN(Rf)O·, where Ar= 2,4,6-tri-t-butylphenyl, phenyl, pentafluorophenyl, and 2,3,5,6-tetramethylphenyl and Rf=trifluoromethyl, pentafluoroethyl, and heptafluoroisopropyl were explored. The temperature dependence of hyperfine splitting constants was studied in the cases of 2,4,6-tri-t-butylphenyl and pentafluorophenyl nitroxides. In the former nitroxides the conformation of β-fluorine atoms are rigid and dihedral angles between the Cβ–F bonds and pz orbitals are 30 and 0° when perfluoroalkyl groups are ethyl and isopropyl, respectively. The conformational dependence of β-fluorine splitting constants are discussed, and it is concluded that the cos2θ law, aβF=(B0+Bcos2θ)ρπ, is also applicable to β-fluorine splitting constants in a series of nitroxides. The values of B0 and B seem significantly dependent on the compound.
The Synthesis of 3-Amino-3-deoxy-d-allose and Related Substances
Authors: Koto Shinkiti , Kawakatsu Noboru , Zen Shonosuke 
Published: July 2006

Abstract
Starting from methyl 2,4,6-tri-O-benzyl-α-d-glucopyranoside, a facile synthesis of 3-amino-3-deoxy-d-allose was carried out; some new O-benzyl derivatives of 3-amino-3-deoxy-d-allopyranose are also described.
Stereochemical Studies on the Halogenation of Sulfoxides. I. The Chlorination of Cyclic Sulfoxides
Authors: Iriuchijima Shinobu , Ishibashi Mariko , Tsuchihashi Gen-ichi 
Published: July 2006

Abstract
The cyclic sulfoxides, thiane 1-oxide, cis- or trans-4-chlorothiane 1-oxide, and cis- or trans-4-phenylthiane 1-oxide, were chlorinated with t-butyl hypochlorite, sulfuryl chloride, and chlorine in the presence of potassium acetate or pyridine. The stereoformulas of the products, together with those of the isomers having an inverted sulfoxide configuration, were determined by means of the IR and NMR spectral data and the Rf-values in the tlc. Consequently, it has been found that chlorination occurs when the sulfinyl oxygen is equatorial and that chlorine is always introduced at a trans-position to the sulfinyl lone pair to give rise to the cis-products. A mechanism accommodating these results is proposed. The conformation of the substituted thiane 1-oxide rings is also discussed.
The Preparation of 5,8-Quinolinediol and 1,4-Acridinediol Derivatives
Authors: Oguchi Sh\={o}shichi 
Published: July 2006

Abstract
Compounds of 6,7-di X substituted 5,8-quinolinediol (X=COOC2H5; CN; COCH3) have been prepared from diethyl pyridine-2,3-dicarboxylate and the respective active methylene compounds. Similarly, 2,3-di X substituted 1,4-acridinediol (X=COOC2H5) has been prepared.
Lilac Aldehydes
Authors: Wakayama Seiji , Namba Satoshi 
Published: July 2006

Abstract
New odorous aldehydes, diastereomers, have been found in lilac flower oil and named lilac aldehydes. The structure was established to be 2-(1′-formyl)ethyl-5-methyl-5-vinyl tetrahydrofuran. Absolute configurations have also been inferred.
Pyrolysis of Tris (2,3-dibromopropyl) Phosphate and Its Related Compounds
Authors: Okamoto Yoshiki , Kimura Norio , Sakurai Hiroshi 
Published: July 2006

Abstract
The main product obtained by the pyrolysis of halogenated alkyl phosphate was found to be alkyl halide. The phosphoryl group was substituted for the halogen atom, olefins being minor products.
The Crystal Structure of Acridinium Bis(7,7,8,8-Tetracyanoquinodimethanide), ARD+(TCNQ)2− and Some Remarks on the Possibility of a Peierls Distortion of a Linear Chain of TCNQ
Authors: Kobayashi Hayao 
Published: July 2006

Abstract
Crystals of acridinium-TCNQ(ARD(TCNQ)2) are triclinic, space group P\bar1 with a=3.841(2), b=13.018(6), c=18.370(12)Å, α=114.32(5), β=119.31(4), γ=90.57(7)° and Z=1. ARD and TCNQ, are separately stacked to form columns along the a axis. Each ARD column is surrounded by six TCNQ, columns. The orientation of ARD is disordered. Intermolecular distance between adjacent TCNQs is 3.246 Å and that between adjacent ARDs is 3.418 Å. The possibility of a Peierls distortion of TCNQ columns was discussed on the basis of the model of one-dimensional distorted lattice. Calculations of free energy show that alternation of intermolecular spacing disappears at Peierls transition temperature, Tp of about 200 K. For T&gt;Tp, the one-dimensional band is not split (metallic), while it is split below Tp(semiconductive). The specific heat curve shows a peak at about 180 K and the heat of transition is calculated to be about 130 cal/mol.
Some Environmental Effects on the shf Lines in the ESR Spectra of Vanadyl Tetraphenylporphin
Authors: Sato Mitsuo , Kwan Takao 
Published: July 2006

Abstract
The ESR spectra of vanadyl tetraphenylporphin (VOTPP) have been studied in a number of organic matrices, with special attention paid to the resolution of the nitrogen shf lines. The matrices were classified into three groups according to their effects on the resolutions of the vanadium hf lines and of the nitrogen shf lines. In the A-group matrices, the spectra of VOTPP displayed well-resolved hf lines, accompanied by shf splittings; in the B-group matrices, the spectra gave rise to well-resolved hf lines, but without shf splittings, and in the C-group matrices, the hf lines were resolved only poorly. It is suggested that a high dispersion of VOTPP molecules is required for the higher resolution of spectra.
The ESR of the Fast-rotating –CH2 of the Radical Formed by the Photolysis of CH2I2 on Silica Gel
Authors: Shimokoshi Kazuo 
Published: July 2006

Abstract
The electron spin resonance spectra have been measured for the radical formed by the photolysis of methylene iodide adsorbed on silica gel. The spectra were anisotropic and were attributed to the radical of the ≡Si–O–CH2form by an analysis of the hyperfine splittings due to two protons, taking into consideration the photochemical processes on the silica gel surface. From a line-shape analysis of the observed spectrum, the following anisotropic hyperfine interaction parameters for the protons and g-value have been obtained:
A_//=28.5±0.5G, A_⊥=18.8 ±0.5G, g=2.0030±0.0005.
It has been concluded from the analysis of the spectra that the hyperfine structure observed with axially-symmetric tensors is a result of the fast internal rotation of the methylene group of the radical.
The Diazotization of 2-Aminoazulene Derivatives. The Formation of 2-Diazo-2,6-azulenoquinone Derivatives
Authors: Nozoe Tetsuo , Asao Toyonobu , Susumago Hiroshi , Ando Masayoshi 
Published: July 2006

Abstract
The Diazotization of 2-amino-6-bromo (or alkoxy)-azulene, with alkoxycarbonyl or cyano groups at the 1 and 3-positions, by sodium nitrite in dioxane–sulfuric acid afforded mainly the corresponding 2-diazo-2,6-azulenoquinone derivatives (2a, 2b, 16). The catalytic hydrogenation of these compounds gave 1,3-disubstituted 6-hydroxyazulenes (4a, 4b, 18), from which 1,3-disubstituted 6-alkoxy- or 6-acetoxy-azulenes were obtained. The diazotization of diethyl 2-amino-6-bromoazulene-1,3-dicarboxylate (1a) in dry benzene with isoamyl nitrite in the presence of hydrogen chloride afforded the 2,6-dichloroazulene derivative (20) and the 5-bromo-2-diazo-2,6-azulenoquinone derivative (21); the latter, accompanied by a bromine addition product (22), was also obtained by the bromination of 2a. The diazotization of diethyl 2-aminoazulene-1,3-dicarboxylate (25) afforded 2a and a deamination product (26). The structure and mechanism of the formation of these diazoazulenoquinones are discussed.
The Effect of Ion Exchange on the 1,2-Epoxybutane-Isomerization Activity
Authors: Matsumoto Shigemi , Nitta Masahiro , Aomura Kazuo 
Published: July 2006

Abstract
The isomerization of 1,2-epoxybutane was studied over NaA-type zeolite and its zinc-exchanged forms in a flow system. The catalytic activity increased from 31 to 92% upon the replacement of Na+ by Zn2+. This increase may be the consequence of the enlargement of the zeolite pore size and the increase in the surface acidity.
Polarized Raman Spectra of (NH4)2SO4 Single Crystals
Authors: Uchida Katsuo , Takahashi Hiroaki , Higasi Keniti 
Published: July 2006

Abstract
Polarized Raman spectra of (NH4)2SO4 single crystals were measured at room temperature. The symmetry species of the observed Raman bands due to the internal vibrations of SO42− as well as the lattice modes were determined.
A Polarographic Study of the Complex Formation Equilibria of Lead(II) Ions with Glutamate and Ethylenediamine-N,N′-diacetate Anions
Authors: Kodama Mutsuo 
Published: July 2006

Abstract
In this experiment, the complex formation equilibria of the lead(II) ions with glutamic and ethylenediamine-N,N′-diacetic acids were studied by using the polarographic method. The lead(II) ion forms 1 : 1- and 1 : 2-ratio complexes with glutamic acid, while, with ethylenediamine-N,N′-diacetic acid, it forms only a 1 : 1-ratio complex, PbX0.
Kinetics of the Oxidation of Acrolein Initiated by Di-t-Butyl Diperoxyoxalate
Authors: Hara Takao , Ohkatsu Yasukazu , Osa Tetsuo 
Published: July 2006

Abstract
The kinetics of the liquid-phase autoxidation of acrolein were studied using di-t-butyl diperoxyoxalate as an initiator. The ratios of the rate constants for the propagation vs the termination steps (k3k6−1⁄2 and k2k4−1⁄2) in the autoxidation mechanism were determined from the empirical rate equation thus obtained. The lower reactivity of acrolein was explained by comparing the ratios with those of saturated aldehydes.
ENDOR Studies of 1,3,5-Triphenylverdazyl Radical and Its Methyl Derivatives. V.
Authors: Mukai Kazuo , Yamamoto Takamitsu , Kohno Masahiro , Azuma Nagao , Ishizu Kazuhiko 
Published: July 2006

Abstract
The ENDOR spectra of 1,3,5-triphenylverdazyl radical and its methyl derivatives were observed in toluene, and the effects of methyl substitution on the proton hyperfine coupling constants were investigated.
The Reaction of Dicarboximides with Benzonitrile in Liquid Ammonia
Authors: Kashima Choji , Yamamoto Makoto , Kobayashi Susumu , Sugiyama Noboru 
Published: July 2006

Abstract
Acyclic dicarboximides were treated with benzonitrile in the presence of sodium amide to give 4-hydroxypyrimidines. However, the reaction of succinimide with benzonitrile gave 5-hydroxy-2-phenyl-2-pyrroline-3-carboxamide. Also, glutarimide gave a similar product.
A Platinum Complex Bound to Iodinated Polystyrene by a Platinum-Carbon σ-Bond
Authors: Kawata Noboru , Mizoroki Tsutomu , Ozaki Atsumu 
Published: July 2006

Abstract
A platinum complex bound to iodinated polystyrene was prepared by the reaction of Pt(Pφ3)4 with iodinated polystyrene. The reaction of the synthesis was confirmed by means of direct oxidative addition of aryl iodide to Pt(Pφ3)4.
Base Catalyzed Oxygenation of 3,5-Di-t-butylpyrocatechol and Its Related Compounds
Authors: Nishinaga Akira , Itahara Toshio , Matsuura Teruo 
Published: July 2006

Abstract
The oxygenation of 3,5-di-t-butylcatechol (1) and its related compounds 3,5-di-t-butyl-o-benzoquinone (2), 4,6-di-t-butylpyrogallol (3), 2,4-di-t-butyl-5-oxo-2-hexenedioic acid (4), 2,4-di-t-butyl-4-(carboxyhydroxymethyl)-2-buten-4-olide (5), and 3,5-di-t-butyl-6-carboxy-2-pyrone (6) in DMF–ButOK gave 2,4-di-t-butyl-4-hydroxy-2-buten-4-olide (7b). A possible mechanism and the relation between 4, 5, and 6, the products in aqueous alkaline autoxidation of 1 and 3, are discussed.
The Reaction of β-Hydroxyalkylmercuric Perchlorate with Sodium Formate in an Aqueous Solution
Authors: Shinoda Sumio , Saito Yasukazu 
Published: July 2006

Abstract
The reaction of 2-hydroxy-1-propylmercuric perchlorate with sodium formate in an aqueous solution was found to be a redox-type reaction: CH3CH(OH)CH2HgClO4+HCOONa=CH3CH=CH2+Hg(0)+CO2+H2O+NaClO4. The concentration of the mercurial coordinated by the formate ion was determined in situ by analyzing the geminal 199Hg-1H spin-coupling constant. By changing the ratio of [CH3CH(OH)CH2HgClO4]/[HCOONa], the initial reaction rate was confirmed to be first-order with respect to the formato-mercurial: v=k[CH3CH(OH)-CH2HgOCOH]. From the variation in k with the temperature, the values of Ea=17.5 kcal mol−1 and A=4.0×108 s−1 were obtained. On the grounds of the kinetic isotope effect for DCOONa and the stereochemical study with threo- and erythro-CH3CH(OH)CHCH3HgClO4, a mechanism is proposed in which the reaction proceeds solely through the unimolecular redox-decomposition of the formato-mercurial, involving an anti-elimination of olefin coupled with a two-electron transfer from the formate ligand to the mercurial.
The Addition of Arylpalladium Chloride to 1,5-Cyclooctadiene and endo-Dicyclopentadiene
Authors: Kasahara Akira , Izumi Taeko , Endo Kazuyoshi , Takeda Toru , Ookita Motomu 
Published: July 2006

Abstract
1,5-Cyclooctdiene reacted with phenylpalladium chloride to give di-μ-chloro-bis-(1-phenylcyclooct-4-ene-8σ,4π)-dipalladium(II). Similarly, the reaction of endo-dicyclo-pentadiene with phenylpalladium chloride led to di-μ-chloro-bis-[endo-6-phenyl-3a,4,5,6,7,7a-hexahydro-endo-4,7-methanoindene-endo-5σ,(2–3)π]-dipalladium (II). The σ-bonded structures of these complexes have been confirmed by studies of the IR and NMR spectra.
New Benzofuranosesquiterpenes from Farfugium japonicum. Farfugin A and Farfugin B
Authors: Nagano Hajime , Moriyama Yoshihiko , Tanahashi Yoshiaki , Takahashi Takeyoshi 
Published: July 2006

Abstract
Two new benzofuranosesquiterpenes, farfugin A and farfugin B, have been isolated from Farfugium japonicum (L.) Kitamura, and their structures have been determined as 1 and 2, respectively.
Porous Structure Formed by the Decomposition of the Surface Product on ZnO Preserved in the Atmosphere
Authors: Nagao Mahiko , Morishige Kunimitsu , Takeshita Toshie , Morimoto Tetsuo 
Published: July 2006

Abstract
The slow reaction of ZnO with CO2 and water in the atmosphere is investigated by following the changes in both the surface area of the structure formed and the amounts of CO2 and water evolved, by heating the product in vacuo at increasingly elevated temperatures. The results obtained show that ZnO reacts extremely gradually with CO2 and water cooperatively in the atmosphere to produce an amorphous surface product with a composition approximate to Zn5(OH)6(CO3)2, and that this product is decomposed by heating in vacuo to release the CO2 and water, leaving a porous structure on the ZnO. The surface area of the product was found to change upon heating: first it increases, passes a prominent maximum value at 200 °C, recovers the original value at 500 °C, and further decreases at higher temperatures; this reflects the initial growth and subsequent destruction of the porous structure. Furthermore, it was confirmed that the destruction of such a honeycomb-like structure is promoted by the adsorption of water.