bluuebunny/crossref_metadata_2025 huggingface dataset:
Para Tolylation of Pyridine by Photolysis of Di-p-Tolyl Sulfone and Related Compounds
Authors: Nakabayashi Takeshige , Horii Toyokazu , Kawamura Shunichi , Hamada Masayuki
Published: July 2006

Di-p-tolyl sulfone, sulfoxide and sulfide, p-toluoyl peroxide, and p-iodotoluene were respectively photolyzed in pyridine with a mercury arc lamp. It was found that all the compounds decompose photochemically to yield the isomeric p-tolylpyridines (α,β , and γ). The isomer distribution ratios (β>α>γ) obtained with the sulfone differ from those (α>β>γ) with the other compounds. The presence of acetone in the reaction system remarkably promoted the photochemical conversion of both the sulfone and sulfoxide.
Synthetic Zeolites as Catalysts for the Ring Conversion of γ-Butyrolactone into 1-Substituted 2-Pyrrolidinones
Authors: Hatada Kou , Ono Yoshio
Published: July 2006

Synthetic zeolites were found to be effective catalysts for the synthesis of 1-substituted 2-pyrrolidinone by the reaction of γ-butyrolactone with amines. 1-Propyl-2-pyrrolidinone was obtained in the equilibrium yield with practically 100% selectivity over copper exchanged Y-zeolite at 280 °C. The effects of reaction temperature, contact time and partial pressures of the reactants were examined. A reaction mechanism is proposed for the ring transformation based on the kinetic studies of the reaction of γ-butyrolactone with propylamine.
Studies of the Measurement of the Intermicellar Concentration of Surfactants by Gel Filtration
Authors: Sasaki Tsunetaka , Yasuoka Misako , Suzuki Hitoshi
Published: July 2006

Equations are derived which are used to calculate the intermicellar concentration (Cs) of a surfactant from measurements of the elution volumes of micelles, the elution front and the intermicellar monodisperse molecules or ions. These quantities are obtained by the gel filtration of a surfactant charged in band form through a gel column previously filled with the same surfactant at a lower concentration. The Cs values found are not constant, but increase and the increase becomes less pronounced with the concentration (C) of the surfactant, both for sodium dodecyl sulfate and α-dodecyl-ω-hydroxyhexa(oxyethylene). This confirms that the concentration C–Cs of the micelles which move during the gel filtration is smaller than the usually-employed concentration C–Cm of micelles in a stationary state, where Cm denotes the critical micelle concentration.
Light Scattering by Oligostyrene Solutions
Authors: Kamata Toshio , Nakahara Hisae , Hattori Shigeru
Published: July 2006

Light-scattering photometers were partially modified in order to measure light scattering by low molecular-weight molecules. Corrections to the molecular weights were then theoretically estimated, when the light scattering due to fluid density fluctuations were approximated by that due to the density fluctuations of a pure solvent. The molecular weight of benzene was determined, in an ethyl methyl ketone solvent, using the light-scattering method prior to the determination of the molecular weights of oligostyrene molecules. Measurements of light scattering by oligostyrene molecules with molecular weights from 600 to 20000 were then carried out. The weight-average molecular weight observed by the light-scattering method was compared with the number-average molecular weights which were determined by the vapor-phase osmometric and NMR methods. The molecular-weight heterogeneity of the specimen is discussed. The second virial coefficient, in the ethyl methyl ketone solvent system, was found to change from negative to positive with increasing molecular weight. It is also shown that the molecular optical anisotropy changes markedly in the range of molecular weights between 2000 and 3000, the change being considered to reflect the conformational changes of oligostyrene molecules.
Hydrogen Bonding between Phenols and Nitriles
Authors: Jawed Inam
Published: July 2006

Hydrogen bonding between a number of para-substituted phenols and nitriles was studied by means of infrared spectroscopy using a longer cell. Thermodynamic quantities were determined and found to be the functions of the electronegativity and inductive effect of the phenol and nitrile substituents respectively except for the complexes of t-butyl cyanide for which the −ΔH values were lower than expected. Some correlations among thermodynamic quantities were also established. Both the sample and the reference cells were heated simultaneously by means of a special heating arrangement which minimized the base line errors and made the intensity measurements more accurate.
The Stereochemistry and Reactivity of Metal-Schiff Base Complexes. II. High Stereoselectivity in (1S,2S)-N,N′-1,2-Cyclohexylenebis-(salicylideneaminato)(sal2-(S,S)-chxn) Cobalt(III) Complexes with Amino Acids and the Optical Resolution of Amino Acids with Cobalt(III)-sal2-(S,S)-chxn
Authors: Fujii Yuki , Sano Mitsuo , Nakano Yoshiharu
Published: July 2006

A series of mixed ligand cobalt(III)–Schiff base complexes with the general formula of [Co(sal2-(S,S)-chxn)(aa)] (aa=gly−, l- and d-ala−, l- and d-val−, l- and d-leu−, l- and d-thr−, or l- and d-trp−) were newly prepared from [Co(sal2-(S,S)-chxn)] and amino acids by air oxidation. All the complexes were found to take, stereoselectively, the Λ-cis-β1(fac)-structure, irrespective of the configuration of the amino acids. On the other hand, the reactions of [Co(sal2-(S,S)-chxn)] with an excess of Dl-amino acids in open air gave [Co-sal2-(S,S)-chxn) (aa)], in which l-amino acids were selectively coordinated except for proline. These stereospecificities were found from the opticalpurity measurement of the unreacted amino acids which had been separated from the reaction solutions by extracting the formed complex with chloroform. The configuration and the optical purities of the unreacted amino acids recovered from 1 : 2 reaction solutions (complex: Dl-amino acid) were as follows: ala, (d, 6–10%); leu, (d, 6–8%); met, (d, 6–8%); ser, (d, 10–12%); thr, (d, 27–30%); asp, (d, 16–18%); glu, (d, 6–8%); phe, (d, 29–31%); trp, (d, 41–43%); pro, (l, 48–50%). These stereoselectivities and stereospecificities were explained in terms of the thermodynamic origin and the stereochemical requirement of the complexes.
Oxidation of Cinnamyl Alcohol with Peracetic Acid in Acidic Solvents
Authors: Ogata Yoshiro , Tomizawa Kohtaro
Published: July 2006

Peracetic acid oxidation of cinnamyl alcohol(1) in tetrahydrofuran(THF) at room temperature has been found to give phenylacetic acid(2), benzaldehyde(4) and cinnamyl acetate(5) as major products. A probable first-formed intermediate, 2,3-epoxy-3-phenyl-1-propanol(7), was detected as its derivative (1-phenyl-1,2,3-propanetriol), and also a probable second intermediate, 1-hydroxy-3-phenyl-2-propanone (3), was detected. 3 was found to be converted to 2 by the Baeyer-Villiger reaction. On the other hand, the peracetic acid oxidation of 1 in methanol gave a methanolysis product of oxirane ring, 3-methoxy-3-phenyl-1,2-propanediol(6a), a small amount of a rearrangement product and benzaldehyde. The peracid oxidation of 1 in various solvents was also studied. A probable reaction mechanism is discussed.
Circular Dichroism Spectra of Cobalt(III) Complexes Containing One or Two Azido, Isothiocyanato, and Nitro Ligands. II. trans-Type Bis[(1R,2R)-1,2-cyclohexanediamine] Complexes
Authors: Yamasaki Kiyoshi , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

The trans dianiono type complexes of cobalt(III) containing (1R,2R)-1,2-cyclohexanediamine, trans-[Co(X)2(R,R-chxn)2]+, and -[Co(X)(X′)(R,R-chxn)2]+ (X and X′=N3−, NCS−, or NO2−) were prepared and their circular dichroism (CD) spectra measured in the visible and ultraviolet regions. The CD and absorption behaviors in the so-called specific absorption band region are compared with those of cis-type bis(ethylenediamine) complexes and discussed in relation to the origin of the specific band. In addition, three isomers of the [Co(NCS)(NH3) (R,R-chxn)2]2+ complex are assigned on the basis of their CD spectra.
Metal Complexes of Amino Acids. X. The Preparation and Characterization of Cobalt(III) Complexes of the Type [Co(N)2(O)4] Containing β-Alanine
Authors: Ama Tomoharu , Higa Matsutake , Koine Norio , Yasui Takaji
Published: July 2006

Three geometrical isomers of the bis(β-alaninato)(oxalato)cobaltate(III) and of the (β-alaninato)(glycinato)(oxalato)cobaltate(III) complexes have been prepared and resolved into their optical isomers. Their structures were assigned on the basis of the electronic absorption, 1H NMR and 13C NMR spectra. The circular dichroism spectra of these complexes have been measured and compared with those of the bis(glycinato)(oxalato)cobaltate(III) complexes.
RhCl(PPh3)3-catalyzed Coupling of Diorganomercurials
Authors: Takagi Kentaro , Hayama Naomi , Okamoto Tadashi , Sakakibara Yasumasa , Oka Shinzaburo
Published: July 2006

RhCl(PPh3)3 has been proved to be an effective catalyst for the reaction of various diorganomercurials to give such coupling products as conjugated diyne, conjugated diene, biaryl, and alkane in good yields under mild conditions. A probable mechanism including the oxidative addition of organomercurials to a rhodium complex and the subsequent reaction of two oxidative-addition adducts to yield the product was presented.
Imidazopteridines. I. Synthesis of Imidazo[1,2-c]pteridine and Its Alkyl Derivatives
Authors: Sugimoto Takashi , Shibata Keiko , Matsuura Sadao
Published: July 2006

The synthesis of imidazo[1,2-c]pteridine and its alkyl derivatives is described. The reaction of 4-aminopteridine with chloroacetaldehyde gave the ring-opened 2-formamido-3-(2-imidazolyl)pyrazine and the isomeric 2-amino-3-(1-formyl-2-imidazolyl)pyrazine but no imidazopteridine. 4-Amino-2-methylpteridine and chloroacetaldehyde similarly gave 2-acetamino-3-(2-imidazolyl)pyrazine in high yield. Hydrolysis of these compounds gave 2-amino-3-(2-imidazolyl)pyrazine, which was used as the key intermediate for the synthesis of the title compounds. Thus it reacted with triethyl orthoformate and homologues to give respectively the parent imidazo-[1,2-c]pteridine and its 6-methyl and 6-ethyl homologues. Their 2,3-dimethyl derivatives were prepared likewise from 2-amino-3-(2-imidazolyl)-5,6-dimethylpyrazine, which in turn was prepared from 4-amino-6,7-dimethyl- or 4-amino-2,6,7-trimethylpteridine.
Synthesis of Tetrahydrospectinomycin
Authors: Suami Tetsuo , Nishiyama Shigeru , Ishikawa Hikaru , Okada Hiroshi , Kinoshita Takeshi
Published: July 2006

Condensation of 1,3-bis-N-(benzyloxycarbonyl)actmamine (2) with 2-O-chloroacetyl-4,6-dideoxy-3-O-p-nitrobenzoyl-α-d-xylohexopyranosyl chloride (8), followed by deacylation and catalytic hydrogenation afforded 5-O-(4,6-dideoxy-β-d-xylohexopyranosyl)actinamine (11). Compound 11 was found to be identical with one of the four tetrahydrospectinomycins. 1H and 13C NMR spectra were determined and analyzed.
Dehydroannulenes. VII. Synthesis of 3,7,10,14-Tetrasubstituted 1,8-Bisdehydro[14]annulenes
Authors: Fukui Kunisuke , Nomoto Tateo , Nakatsuji Shin’ichi , Akiyama Shuzo , Nakagawa Masazumi
Published: July 2006

It was found that dienyne ketones such as 2,2-dimethyl-7-t-butyl-4,6-nonadien-8-yn-3-one, 2,2-dimethyl-7-phenyl-4,6-nonadien-8-yn-3-one and 1,5-diphenyl-2,4-heptadien-6-yn-l-one give the corresponding tetrasubstituted 14-membered cyclic glycols on treatment with a suspension of potassium hydroxide in liquid ammonia. Reactions of the cyclic glycols with tin(II) chloride in organic solvent saturated with hydrogen chloride afforded strongly diatropic tetrasubstituted bisdehydro[14]annulenes.
The Addition Reaction of Acyl Radicals to 9,10-Phenanthrenequinone in the Presence of the Corresponding Aldehydes. A Support for the In-Cage Mechanism of the Photochemical Reaction of 9,10-Phenanthrenequinone with Aldehydes
Authors: Maruyama Kazuhiro , Sakurai Hiroshi , Otsuki Tetsuo
Published: July 2006

Regarding the photochemical reaction of 9,10-phenanthrenequinone, 1, with acetaldehyde, 2, two reaction mechanisms have been proposed: the in-cage mechanism (Eq. 1) and the radical chain mechanism involving an acyl radical as the chain carrier (Eq. 2). For the establishment of the true reaction mechanism, the thermal addition reaction of an acyl radical to 9,10-phenanthrenequinone was investigated. The products in the thermal reaction were the dimeric isomers of the aryloxyl radical, 6, i.e., 4 and 5, which were quite different from the product of the photochemical reaction of 9,10-phenanthrenequinone with acetaldehyde, i.e., 9-acetoxy-10-hydroxyphenan-threne, 3. These results, as well as the estimation of the quantum efficiency for the photochemical reaction, exclude the radical chain mechanism (Eq. 2) and strongly support the in-cage mechanism (Eq. 1) for the photochemical reaction of 9,10-phenanthrenequinone with aldehyde.
Measuremets of the Thermal Transpiration Effects of NO at 90 K and of CO, N2, O2, CH4, and He at 77 K
Authors: Furuyama Shozo
Published: July 2006

The thermal transpiration effect of the title gases was measured by a relative method by using a diaphragm-type pressure transducer. The data fit the Takaishi-Sensui equation [P1⁄P2=(AX2+BX+C\sqrtX+\sqrtT1⁄T2)⁄AX2+BX+C\sqrtX+1)] quite well in the region of X(=P2d2) higher than 0.03 mmHg mm. The values for A, B, and C are 25.5, 9.3, and 0.6 for NO at 90 K, 28.5, 10.5, and 0.6 for CO and N2, 24.0, 9.2, and 0.8 for O2, 44.0, 11.4, and 1.2 for CH4, and 2.96, 0.6, and 1.6 for He at 77 k respectively. The values for the temperature-independent constants, A*, B*, and C* deduced from the values for A, B, and C above, were in agreement with the literature values and/or the estimated values.
On the Low Dimensionality in Organo-magnetic Material: 9-(α-Fluorenylidene-p-chlorobenzyl)-9-fluorenyl
Authors: Yamauchi Jun , Deguchi Yasuo
Published: July 2006

The low-dimensional character in the organic free radical, p-Cl-BDPA, is discussed. The temperature dependence of the g-values can provide a method of discrimination between the short- and long-range-ordering effects, and the organic free radical can be regarded as a one-dimensional organo-magnetic material at first approximation, but its interchain interaction is appreciable, amounting to the order of |J′|J|=0.2; thus, |J′|⁄k=0.88 K.
Formation and Characterization of Lead Monoxide Prepared by the Alkoxy-Method
Authors: Yamaguchi Osamu , Yamadera Minoru , Shimizu Kiyoshi
Published: July 2006

Lead alkoxide was hydrolyzed at various temperatures from 28 to 85 °C. The products consisted of only massicot or litharge, or a mixture of the two for modifications of PbO, depending on the reaction temperature and pH of the suspension.
Synthesis and Properties of 2,8-Dioxabicyclo[3.2.1]octane Derivatives
Authors: Irikawa Hajime , Ishikura Tsukasa , Okumura Yasuaki
Published: July 2006

In order to study the isomerization of daphniphylline into isodaphniphylline, 1,4-dimethyl-2,8-dioxabicyclo[3.2.1]octane-4-carboxylic acid (3), a degrada tion product of daphniphylline, was synthesized from the keto diester and transformed into the 3-oxacyclopentanones (6, 7).
Graft Polymerization on Pulverized Solid Surface. I. Grafting Polystyrene on a Clay Surface Treated with Silane Coupling Agents
Authors: Nakatsuka Takuo , Kawasaki Hitoshi , Itadani Katsuhiko
Published: July 2006

Styrene was graft-polymerized on kaolin clay treated with silane coupling agents e.g. (γ-methacryloyloxypropyl)trimethoxysilane. Although the silane-styrene copolymer was soluble in benzene, the polystyrene-grafted clay swelled in the same medium. A clay-crosslinked, threedimensional structure is suggested and conditions for gelation are also discussed.
On the Behavior of Paramagnetic Species Formed in the Pure V2O5 Crystal under SO2-Oxidation
Authors: Kera Yoshiya , Kuwata Keiji
Published: July 2006

Two types of ESR spectra were found in the highly purified V2O5 crystal under conditions of SO2 oxidation. The shapes and the intensities of the spectra were investigated in detail in the temperature range from 470 to 656 °C under various mixing ratios of SO2 to O2. Below ca. 600 °C a sharp and asymmetric spectrum existed stably, while above that temperature it was replaced by a spectrum with an hfs of 29 lines, the intensities of which always were very weak. The low-temperature-type spectrum was reasonably assigned to the VOSO4 phase, and the high-temperature-type, to an oxygen defect surrounded equivalently by four vanadium ions in the V2O5 phase. The interchange between the two spectra near 600 °C occurred reversibly and was related favorably to the following process in the surface layer of the V2O5 crystal: 2VOSO4=V2O5+SO3+SO2. The change in the working states of a pure V2O5 crystal according to the conditions of SO2 oxidation was discussed.
The Adsorption Mechanism of Methanol on Alkali Halides
Authors: Chikazawa Masatoshi , Kanazawa Takafumi
Published: July 2006

The amounts of methanol adsorbed on (100) planes of the crystals of six alkali halides (LiCl, NaCl, NaBr, KCl, KBr, and KI) and the isosteric heats of their adsorption were measured. For the chloride samples, the order of magnitude of the adsorption heats at a coverage of θ=0.5 was found to be LiCl>NaCl>KCl, while the order for the bromide samples was NaBr>KBr. The monolayer capacities estimated from the adsorption isotherms for KCl and NaBr were in accord with the values calculated by assuming that one methanol molecule is adsorbed on one surface anion of the crystal. In the cases of the NaCl and LiCl salts, whose lattice spacings are smaller than that of NaBr, the methanol molecule was adsorbed on the surface anion with a ratio below 1 : 1. On the other hand, for the KBr and KI samples, whose lattice spacings are larger than that of KCl, alcohol was adsorbed on the surface anion in a ratio above 1 : 1. These phenomena are reasonably interpreted in terms of a relationship between the cross-sectional area of a methanol molecule and the lattice spacing of the salt concerned. An adsorptive mechanism deduced from the isosteric heat curves was compatible with the above explanation.
Semiconducting Properties of (LnI, LnII)CuO4 and of (Ln, A)2CuO4 (Ln=rare earth, A=alkaline earth)
Authors: Kenjo Tadao , Yajima Seishi
Published: July 2006

The ternary oxides, (La,Pr)2CuO4, (Gd,Tb)2CuO4, (La,Tb)2CuO4, (La,Ca)2CuO4 and (La,Ba)2CuO4, were prepared and their semiconducting properties were investigated. When the mean ionic radius of Ln3+ (\barr) is increased, the (La,Pr)2CuO4 compounds transform from semiconductors to metals at a critical \barr value of 1.05 Å. The metal-semiconductor transition which accompanies the shrinkage of the a axis, is explained as being due to the π-bond formation of the Cu–O bond. Compounds in the composition range from La1.3Tb0.7. CuO4 to La1.4Tb0.64CuO4 are peculiar to the (La,Tb)2CuO4 compounds. The crystal structure is the same as that of Ln2CuO4, but it is different from Ln2CuO4 as regards the c/a ratio and resistivity. The doping of 20 mol% CaO or 10 mol% BaO into La2CuO4 lowers the resistivity to tenth of that of La2CuO4.
Structural Studies of Asymmetric Hydrogenation. III. The Crystal Structure of (R)-1-(Methoxycarbonyl)ethyl(R)(+)-α-methylbenzylaminebis(dimethylglyoximato)cobalt(III)
Authors: Ohashi Yuji , Sasada Yoshio
Published: July 2006

The structure of (R)-1-(methoxycarbonyl)ethyl(R)(+)-α-methylbenzylaminebis(dimethylglyoximato)cobalt(III) has been determined by X-ray analysis. The crystal is monoclinic, the space group P21  Z=2 with a=7.899(5), b=16.397(2), c=9.054(7) Å, and β=90.98(7)°. The structure was deduced by the heavy atom method and refined by the block-diagonal least-squares method to a final R value of 0.048 for 2146 observed reflections. The bis(dimethylglyoximato) cobalt moiety is twisted around its long axis, owing to the steric repulsion from the (R)-1-(methoxycarbonyl)ethyl group and the optically active amine. It is proposed that this twist is one of the factors inducing the asymmetry in the hydrogenation catalyzed by the complex of bis(dimethylglyoximato)cobalt and the active amine. At the step of Co–C bond cleavage the reaction proceeds mainly through inversion of the configuration.
The Vibrational Spectra and Rotational Isomerism of Methylvinylsilane and Allylsilane
Authors: Ohno Keiichi , Taga Keijiro , Murata Hiromu
Published: July 2006

The infrared and Raman spectra have been measured for methylvinylsilane, CH2=CHSiH2(–D2)CH3, and allylsilane, CH2=CHCH2SiH3(–D3). The fundamental vibrations have been assigned, and the normal coordinate treatment for possible molecular forms has been carried out. For methylvinylsilane, the cis and skew forms coexist in the gaseous and liquid states, while only the former persists in the solid state. In the liquid state the cis form is more stable by 0.66±0.05 kcal/mol than the skew form. For allylsilane, the form near the skew form predominantly exists in the gaseous, liquid, and solid states.
The Crystal and Molecular Structures of trans-Bis(trimethylphosphine)-[1,2-bis(methoxycarbonyl)vinyl](phenylethynyl)palladium(II)
Authors: Yasuda Takao , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami
Published: July 2006

The X-ray molecular structure of the addition product of trans-HPd(PEt3)2(C≡CPh) with dimethyl acetylene-dicarboxylate has been determined to be [trans-{(MeO2C)HC=C(CO2Me)}Pd(PEt3)2(C≡CPh)]. The crystal belongs to the monoclinic system, space group P21/c, with eight formula units in a cell with dimensions of a=17.844(3), b=9.476(3), c=36.061(4) Å, β=98.18(1)°. Two independent molecules have similar structures except for the conformation of the phenylethynyl groups and one of the triethylphosphine groups. The 1,2-bis(methoxycarbonyl)vinyl and phenylethynyl groups are σ-bonded to the palladium atom. No significant difference is observed between the Pd–C(sp)[2.04(2) and 2.03(2) Å] and Pd–C(sp2)[2.05(2) and 2.06(2) Å] bond lengths. The environment of the palladium atom is approximately square-planar: Pd–P=2.321(5), 2.312(5), and 2.305(5), 2.311(5) Å.
Solution Properties of Phycocyanin. IV. Studies of the Self-association Equilibrium of Phycocyanin in a pH 6.8 Solution
Authors: Iso Naomichi , Mizuno Haruo , Saito Takahide , Nitta Noriko , Yoshizaki Katsuaki
Published: July 2006

The self-association of phycocyanin in a buffer of pH 6.8 with an ionic strength of 0.1 has been studied by sedimentation equilibrium measurements in the temperature range from 5.2 to 25 °C. The self-association of this system increases with a decrease in the temperature. A quantitative evaluation of the experimental data for this system indicates that the type of the association reaction is not a simple mechanism such as a monomer\ightleftharpoonsn-mer, but the discrete monomer\ightleftharpoonstrimer\ightleftharpoonstetramer mechanism is probable. Several thermodynamic quantities, such as the Gibbs free energy change, ΔG°, the enthalpy change, ΔH°, and the entropy change, ΔS°, accompanying the self-association reaction were computed on the basis of the equilibrium constants. From the results, it is considered that the association process is similar to the ordinary crystallization, and that the formation of a tetramer proceeds at a higher concentration than that in which the trimerization reaction is completed.
The Mutual Separation of 227Ac, 227Th, 223Ra, and 223Fr by the Solvent Extraction Technique Using Bis(2-ethylhexyl)phosphoric Acid as an Extractant
Authors: Mitsugashira Toshiaki , Yamana Hajimu , Suzuki Shin
Published: July 2006

The separation and purification of 227Ac, 227Th, 223Ra, and 223Fr were studied by the solvent extraction method using HDEHP (bis(2-ethylhexyl)phosphoric acid) as an extractant. The mutual separation of Ac, Th, and Ra was achieved, and new milking processes for 223Fr and 228Ac are presented.
Hydrolytic Behavior of Oxovanadium(IV) Ions
Authors: Komura Akitoshi , Hayashi Mutsuo , Imanaga Hiroto
Published: July 2006

The hydrolysis of VO2+ was investigated in 0.1 M LiClO4 by potentiometric, conductometric and turbidimetric measurements. The following values of the equilibrium constants were obtained: β11=[VOOH+] [H+]⁄[VO2+]=9.0×10−6 M (M=mol dm−3); β22=[(VO)2(OH)22+][H+]2⁄[VO2+]2=1.9×10−7 M. The solubility product of VO(OH)2 given by Kspl=[VO2+][OH−]2 was found to be 6.6×10−23 M3 from the pH values at which precipitation occurs. Only one species with a stoichiometric ratio VO/OH=2.5 is present in basic solutions in the pH range 9–12. The solubility product of VO(OH)2 given by Ksp2=[H+][(VO)2(OH)5−] is logKsp2=−11.1. A less soluble salt Na(VO)2(OH)5 or NaHV2O5 was isolated from strongly basic solutions. Measurements of Na+ concentration at which the solid phase first appears give logKsp3=−3.74 as its solubility product, Ksp3=[Na+][(VO)2(OH)5−].
Formation and Properties of Strontium Uranates
Authors: Tagawa Hiroaki , Fujino Takeo , Tateno Jun
Published: July 2006

The formation and nonstoichiometry of strontium uranates, especially those with the Sr/U atom ratio around unity, were examined by means of thermogravimetry and X-ray diffraction. The reaction of SrCO3 with U3O8 in air, where Sr/U=1, produced the stoichiometric β-SrUO4, which had an orthorhombic structure. The reactions in vacuum and in hydrogen yielded the products of the composition SrUO3.563 and SrUO3.175, respectively. On the other hand, the reduction of β-SrUO4 in vacuum and in hydrogen gave SrUO3.48 and SrUO3.65, respectively. Stoichiometric SrUO3 was prepared by the reaction of SrO with UO2. The reduction product of β-SrUO4, SrUC4−x, was oxidized in air below 500 °C to α-SrUO4 which was rhombohedral. During the phase transition to β-SrUO4, α-SrUO4 exhibited anomalous behavior; that is, α-SrUO4 was first reduced and then reoxidized to nearly the initial composition with the formation of β-SrUO4. Of the uranates with Sr/U\eweq1, the formations of SrU4O13, SrU2O7, and Sr2UO5 were examined; the single phase SrU2O7 was not obtained. Thermograms for their reduction, followed by the oxidation of the resultants, suggest the existence of the compounds SrU4O11 and SrU2O6.0−6.6. No uranates containing only U(IV) were obtained by hydrogen reduction of the uranates containing U(VI) formed in air at high temperatures.
The Liquid-Phase Oxidation of Aldehydes with Metal Tetra(p-tolyl)porphyrins
Authors: Ohkatsu Yasukazu , Osa Tetsuo
Published: July 2006

The effects of the kind of metal of metal porphyrins and the substituent of the phenyl group of porphynato plane were discussed, using them as catalysts in the autoxidation of aldehydes. The effect of the solvent and the additive on the above-mentioned catalytic activity of the porphyrins was put into order by means of their pKa(BH+) and pKa(BH+) values; the increased pKa(BH+), namely, the electron-donating power of solvents, seemed to lead to their strong coordination, followed by the initiation of the coordination of oxygen. On the other hand, the oxygen which had been activated on the porphyrins was estimated to react with or be stabilized by a solvent with a low pKa(H+); it could not initiate the autoxidation with ease.
The Kinetics and Mechanism of the Radical Addition of Hydrogensulfite Ions to 1-Dodecene in a Micellar Solution of Sodium 1-Dodecanesulfonate
Authors: Miyata Teijiro , Sakumoto Akihisa , Washino Masamitsu
Published: July 2006

The addition reaction induced by Co-60 gamma-rays proceeded without any detectable induction period under homogeneous conditions in the presence of sodium 1-dodecanesulfonate. The consumption rate of 1-dodecene was equal to that of sodium hydrogensulfite and proportional to the square roots of the hydrogensulfite-ion and 1-dodecene concentrations. The g-value of 1-dodecene consumption was 860 at the concentrations of 0.260 mol/l of sodium hydrogensulfite, 0.0966 mol/l of 1-dodecene, and 0.11 mol/l of sodium 1-dodecanesulfonate at the dose rate of 2.70×1015 eV/g·s and the dose of 1.62×1018 eV/g. The apparent rate constant was 2.6×10−4 s−1 under these reaction conditions. The reaction of CH3(CH2)9CHCH2SO3− with the sulfite radical ion was proposed as the termination step of the reaction.
The Reaction of N-(Phenylsulfonyl)benzohydrazonoyl Chloride with N-Substituted Benzamidines, with Benzimidates, and with 2-Aminopyridines
Authors: Ito Suketaka , Tanaka Yumo , Kakehi Akikazu , Miyazawa Hirotaka
Published: July 2006

4-Alkyl or aryl-3,5-diphenyl-4H-1,2,4-triazoles, 3-phenyl-1,2,4-triazolo[4,3-a]pyridine, and -pyrimidine are obtained by the title reactions. The reaction may proceed via the nucleophilic attack of amidine or imidate on the imidoyl carbon of hydrazonoyl chloride and the subsequent intramolecular cyclization of the intermediate formed in the initial step, with the removal of the amino or alkoxyl and phenylsulfonyl groups.
Fluorescence of 9-Aminoacridine Bound to Polynucleotides
Authors: Kubota Yukio , Fujisaki Yasuo
Published: July 2006

The fluorescence of 9-aminoacridine is completely quenched when bound to poly (dG)·poly (dC), the quantum yield of fluorescence being nearly equal to that of free dye when bound to poly d(A–T). The dye bound to DNA shows a weak fluorescence for which the AT pair is responsible.
Light-induced Conformational Changes of Polypeptides. Random Copolymers of γ-Benzyl-l-glutamate with m- and p-Phenylazobenzyl-l-aspartates
Authors: Ueno Akihiko , Anzai Jun-ichi , Osa Tetsuo , Kadoma Yoshinori
Published: July 2006

Copolymers of γ-benzyl-l-glutamate with m- and p-phenylazobenzyl-l-aspartates were prepared for investigating the effect of side-chain photoisomerization on their conformations. A study was made of the circular dichroism associated with the n,π* transition of the amide group, as well as the extrinsic bands associated with the azo chromophore. The intensity of the 222-nm amide band seems unaffected by the interaction with the side-chain chromophore. The circular dichroism spectra before irradiation indicate that poly[β-(m-phenylazobenzyl)-l-aspartate] (mPALA) adopts a left-handed α-helical form and the other copolymers a right-handed form in 1,2-dichloroethane. After irradiation, remarkable changes of the 222-nm band were observed for the meta copolymer with 89.3% azo residues and mPALA. The increased absolute ellipticity for the former indicates that photoisomerization enhances the helicity of the polymer. Decrease in ellipticity for the latter indicates that photoisomerization induces significant instability of the left-handed α-helical conformation. In the course of subsequent relaxation of mPALA, an abrupt change in the CD spectra was found above 50% of cis followed by a gradual change with decreasing cis%.
Selective Hydrogren Atom Abstraction by Hydrogen Atoms in Photolysis of Cyclohexane-Pentane Mixtures at 77 K
Authors: Miyazaki Tetsuo , Guedes Selma M L , Silva Leonardo G de A e , Fernandes Lizete
Published: July 2006

The reaction of H atoms, produced by the photolysis of HI, has been studied in c-C6H12-n-C5H12 mixtures at 77K. H atoms in c-C6H12 matrix react more effectively with solute n-C5H12 than with solvent c-C6H12, while H atoms in n-C5H12 matrix react more effectively with solute c-C6H12 than with solvent n-C5H12.
On the Mechanism of the Formation of Steroidal Cyclic Hydroxamic Acids in the Photolysis of Steroidal 17β-ol Nitrite
Authors: Suginome Hiroshi , Yonekura Norihisa , Mizuguchi Terutoshi , Masamune Tadashi
Published: July 2006

The Photolysis of 5α-androstane-3α, 17β-diol 3-acetate 17-nitrite (1) in benzene with monochromatic light (372±4 nm) afforded two rearranged products, 17a-aza-d-homo-5α-androstane-3α,17a-diol-17-one 3-acetate (2) and the C-13 epimer (8). This result confirmed that the cyclization of the nitroso aldehyde intermediate (C) to the two products 2 and 8 proceeds without the involvement of excited species of the nitroso aldehyde intermediate C. This conclusion differs from that obtained for bornyl and isobornyl nitrites by Kabasakalian and Townley. The results of photolysis in carbon tetrachloride are also compared with that in benzene. The photolysis of the nitrite 1 in an EPA matrix at 77 K showed that essentially no β-cleavage of the 17β-oxyl radical takes place at the temperature of liquid nitrogen.
Competitive Cyclization in the Reaction of Hexafluoropropene with 2-Aminobenzamide
Authors: Nakai Takeshi , Hassan Nabil M , Ishikawa Nobuo
Published: July 2006

The reaction of hexafluoropropene(HFP) with 2-aminobenzamide afforded 2-(1,2,2,2-tetrafluoroethyl)-4(3H)-quinazolinone (4) and N-(2-cyanophenyl)-2,3,3,3-tetrafluoropropionamide (5) in ca.1 : 1 ratio, which is essentially independent of the reaction temperatures ranging from room temperature to 100 °C. The formation of the two products is explained in terms of the competitive cyclization of the imidoyl fluoride intermediate, the N-6 and O-6 ring closures ultimately yielding 4 and 5, respectively. In contrast to the HFP reaction, 2-(trifluoromethyl)pentafluoropropene (OFIB) and 2-aminobenzamide gave only the O-6 cyclized product, N-(2-cyanophenyl)-2-trifluoromethyl-3,3,3-trifluoropropionamide. The difference in reactivity between HFP and OFIB is discussed.
Odor and Volatile Compounds in Liquid Swine Manure. II. Steam-distillable Substances
Authors: Yasuhara Akio , Fuwa Keiichiro
Published: July 2006

Many aliphatic hydrocarbons, nitrogen-containing compounds, and other substances were isolated from neutral or alkaline liquid swine manure by steam distillation and column chromatography, and identified by means of gas chromatography-mass spectrometry. Aliphatic hydrocarbons have an oily odor, and nitrogen-containing substances, particularly indole, skatole, and o-aminoacetophenone, have a strong malodor. Sulfur-containing substances which have a strong malodor have been detected in a trace quantity.
Effects of Neighboring Functional Groups in the Asymmetric Reduction of ω-Substituted Alkyl Phenyl Ketones with Lithium Tri-l-Menthoxyaluminum Hydride
Authors: Yamaguchi Shozo , Kabuto Kuninobu
Published: July 2006

In the enantioselective reduction of ω-substituted alkyl phenyl ketones, PhCO(CH2)nY, with lithium tri-l-menthoxyaluminum hydride, the effect of the functional groups, Y(NR2, OMe, and SMe) on the stereoselectivity was examined in comparison with that of the alkyl group. Of the functional groups tested, the MeO group is more effective in enhancing the stereoselectivity than the NMe2 or SMe group except in the case of n=1. The optical yields are also affected by the number of the methylene group (n) in the substrates. These results strongly suggest that the coordination of the Y group with the reducing reagent is one of the essential factors in the stereoselectivity. The absolute configurations of the resulting alcohols are correlated with the relative magnitudes of the lanthanideinduced shifts(LIS) of their (+)-MTPA esters.
The Silver(I) Ion-catalyzed Oxidation of Ethylenediaminetetraacetatocobaltate(II) by the Peroxodisulfate Ion
Authors: Ohashi Kousaburo , Yamamoto Katsumi
Published: July 2006

A spectrophotometrie study of the silver(I) ion-catalyzed oxidation of the ethylenediaminetetraacetatocobaltate(II) (CoII-edta) peroxodisulfate ion (S2O82−) was carried out in acidic media. The rate is independent of the concentration of CoII-edta, but first-order-dependent with respect to the concentrations of S2O82− and Ag(I) in the 1.67×10−2–7.25×10−2 M and 2.00×10−3–2.26×10−2 M ranges respectively.
1H and 13C NMR of 2,2′-Bipyridine Adducts with Butyltin(IV) Trichloride and Tin(IV) Tetrachloride, and Tetrabromide
Authors: Matsubayashi Gen-etsu , Iyoda Jun
Published: July 2006

1H and 13C NMR spectra of 2,2′-bipyridine adducts of butyltin(IV) trichloride and tin(IV) tetrachloride and -bromide have been measured in N,N-dimethylacetamide. On the basis of the chemical shifts of the 13C nucleus and spin-spin coupling constants of the 117⁄119Sn with the ligand 1H and 13C nuclei the configuration of the adducts and the nitrogen-tin coordination bond are discussed.
A New Measure of Aromatic Stabilization: Resonance Energy per π Bond (REPB)
Authors: Aihara Jun-ichi
Published: July 2006

A concept of resonance energy per π electron appears unsuitable for representing the aromatic stabilization of a conjugated compound. If the resonance energy is divided by the number of π bonds constituting π rings in the conjugated system, though, a reasonable index is obtained for the same purpose.
The Acid-catalyzed Reaction of Alicyclic Ketones with Formaldehyde. II. The Reaction of Cycloheptanone and Cyclooctanone with Formaldehyde
Authors: Hirano Fukumi , Wakabayashi Shoji
Published: July 2006

The acid-catalyzed reaction of cycloheptanone and cyclooctanone with formaldehyde gave predominantly 2,4-dioxaspiro[5.6]dodecan-7-one and 2,4-dioxaspiro[5.7]tridecan-7-one respectively.
A Convenient Preparation of Arylthioynamines
Authors: Nakai Takeshi , Tanaka Kiyoshi , Setoi Hiroyuki , Ishikawa Nobuo
Published: July 2006

(2,2,2-Trifluoroethylthio)benzenes prepared from sodium thiolates and 2,2,2-trifluoroethyl p-toluenesulfonate reacted with 3 equiv of lithium dialkylamides in diethyl ether to give arylthioynamines in good yields. The present procedure gives good results with aliphatic sulflde.
Chemical Synthesis of Antigenic Determinants of Hen Egg-White Lysozyme. II. Tetradecapeptide Corresponding to Positions 1–14 in the Primary Structure but with Ala6 and Met(O)12
Authors: Kumagae Shin-ichiro , Shimonishi Yasutsugu
Published: July 2006

For characterizing one of the antigenic determinants of hen egg-white lysozyme in delayed hypersensitivity, the tetradecapaptide, H–Lys–Val–Phe–Gly–Arg–Ala–Glu–Leu–Ala–Ala–Ala–Met(O)–Lys-Arg–OH, was synthesized by the solid phase method using ultrasonic waves. This peptide corresponds to positions 1–14 of the amino acid sequence of hen egg-white lysozyme but with alanine and methionine S-oxide residues at positions 6 and 12, respectively.
A Phenomenological Description of Electron Paramagnetic Double-Resonance Relaxation of Organic Free Radicals in Solution. II. ENDOR Relaxation of Galvinoxyl
Authors: Shikata Hideo , Ishizu Kazuhiko
Published: July 2006

The ratio of the ENDOR enhancement to the ESR intensity (E) of galvinoxyl in toluene was measured under various conditions of microwave power, rf power and temperature. The results are discussed in comparison with a phenomenological theory in part I. It is proven that the apparent longitudinal electron spin relaxation time for a t-butyl proton under NMR excitation is about twice as long as those for methylidyne and ring protons, which is explained by the effect of incomplete hf separation. Also, it is shown that the reciprocal of the slope of the plot of E−1  vs. (rf power)−1 for methylidyne and ring protons is approximately proportional to the number of equivalent protons, whereas that for a t-butyl proton can be explained only if the effect of incomplete hf separation is taken into consideration. The value of b=Wn⁄We for methylidyne and ring protons, simulated from the temperature dependence of E based on a previous theory, can be closely correlated to the spin distribution in galvinoxyl.
Studies on Mixed Chelates. VIII. Mixed Copper(II) Chelates with N,N′- and N,N-Dialkylethylenediamines and Acetylacetone
Authors: Fukuda Yutaka , Okamura Hiroko , Sone Kozo
Published: July 2006

Mixed chelates [Cu(diamine)(acac)]X(diamine: N,N′- and N,N-dialkylethylenediamines) were studied. Two such chelates with diethyl ligands were obtained in crystalline state, while the formation of chelate cations [Cu(diamine)(acac)]+ in 80% dioxane was studied with dimethyl ligands, and their formation constants estimated. The importance of steric effect in the bis-diamine chelates on the ease of formation of this type of chelate was pointed out.
Nuclear Quadrupole Resonances of AlBr3·SbBr3, AlI3·SbI3, and AlBr3·BiBr3
Authors: Okuda Tsutomu , Yamada Koji , Ishihara Hideta , Negita Hisao
Published: July 2006

The quadrupole coupling constants (e2Qq⁄h) and the principal axes of electric field gradient (efg) at 81Br, 127I, 27Al, 121Sb, and 209Bi in AlBr3·SbBr3, AlI3·SbI3, and AlBr3·BiBr3 were determined by means of NQR or NMR, in order to clarify the structures and chemical bonds of these compounds. The NQR spectra of AlBr3·SbBr3 and AlI3·SbI3 resemble each other and these two compounds consist of V-shaped SbX2+ and distorted tetrahedral AlX4− ions (X=Br and I). However, there are weak bonds between the Sb atom in SbX2+ and the halogens in AlX4− ion. The V-shaped SbX2+ has the bond angle 97.3° for the bromide and 99.0° for the iodide. The orientation of the efg axes at the 121Sb atom suggests that the antimony atom has a lone pair of electrons in the opposite direction to the bisector of the two Sb–X bonds. On the other hand, only one terminal bromine atom bonded to the Bi atom was found for AlBr3·BiBr3.
Polarized Absorption Spectra and Configuration Analyses of Xanthene and Xanthone
Authors: Minegishi Tsuneyuki , Hoshi Toshihiko , Hiratsuka Hiroshi , Tanizaki Yoshie
Published: July 2006

The polarized absorption sepctra of xanthene and xanthone were measured in stretched poly (vinyl alcohol) films, and the polarization direction of each electronic transition was determined. It was confirmed that xanthone has the short molecular-axis polarized bands (1A1←1A1) at 343, 260, and 226 nm, and the long molecular-axis polarized ones (1BA2←1A1) at 290, 266, and 242 nm. The electronic transitions of xanthone are discussed in connection with those of xanthene by use of the configuration analysis. For the 266 and 260 nm bands, the contributions of the intramolecular charge transfer character from the xanthene skeleton to the carbonyl group are considerable.
Crystal and Molecular Structure of α-Form of 2,4,6-Trimethyl-1,3,5-trithiane
Authors: Sekido Kiyotane , Ono Haruaki , Noguchi Teruo , Hirokawa Sakutaro
Published: July 2006

The crystal structure of α-form of 2,4,6-trimethyl-1,3,5-trithiane (α-TTA) has been determined by the X-ray method. The crystal data are a=9.768, b=12.306, c=8.521 Å, and β=116.33 °. The space group is Cc with four molecules in a unit cell. The structure was deduced from interpretation of the 3D-Patterson series, and refined by 3D-Fourier and least-squares method to the final R factor of 0.040 for 1371 reflections. The molecule has a six-membered ring where three sulfur atoms and three carbon atoms are linked alternatively, forming a chairform. Two methyl groups are in the equatorial positions and one methyl group in the axial. The mean values of the bond distances are 1.818 Å for S–C and 1.519 Å for C–Ceq. The distance is 1.541 Å for C–Cax. The mean values of the bond angles are 101.89° for C–S–C, 107.60° for S–C–Ceq, 113.25° for S–C–Cax, and 112.92° for S–C–S.
Solid-State Anodic Oxidation of Aluminum with Organic-Conductor Counterelectrode
Authors: Yoshimura Susumu , Murakami Mutsuaki
Published: July 2006

Solid-state anodic oxidation of aluminum contacted to a pellet of various organic conductors based on 7,7,8,8-tetracyanoquinodimethane was observed. A typical passivation curve was observed in the current-voltage characteristics for the anodic polarization of the metal. Along with impedance measurements on the electrode system, it was proved that the passivation is due partly to a thermal transformation in the organic conductor and partly to a solid-state anodization of aluminum, the latter being conditioned by the former through the formation of an electrolyte layer in situ. The current efficiency of anodization was estimated by a linear voltage sweep method to be as high as 2%, depending on the ambient moisture. The high efficiency explains the prominent self-healing action of a new type of solid electrolytic capacitor in which manganese dioxide is replaced by an organic-conductor counterelectrode.
NMR Study of Spontaneous Degradation of Penicillin G in Aqueous Solution
Authors: Mitsumori Fumiyuki , Arata Yoji , Fujiwara Shizuo , Muranaka Masaharu , Horiuchi Yoshihiko
Published: July 2006

The spontaneous degradation of penicillin G in aqueous solution has been studied using NMR and thin layer chromatography. Correlation NMR spectroscopy was used to follow products which appear at the early stage of degradation. It has been found that in 0.3 M phosphate buffer (pH 7.0, 30 °C) a successive first order degradation

penicillin G \xrightarrowk1 penicilloic acid \xrightarrowk2 secondary product

is dominant with kinetic constants of k1=0.7×10−2 h−1 and k2=6×10−2 h−1.
The Crystal Structures of Tin(II) Chloride Dihydrate in High- and Low-Temperature Phases as Studied by Neutron and X-Ray Diffractions
Authors: Kitahama Katsuki , Kiriyama Hideko
Published: July 2006

The neutron-diffraction results for deuterated single crystals have shown definitely that the phase transition is ascribable to the ordering of the hydrogen atoms. The ordered arrangement below the transition temperature (Tt=234 K) agrees well with the NMR results. No doubling of the unit cell or loss of the center of symmetry can be detected. In the disordered phase above Tt, four deuterons of two non-equivalent water molecules are distributed into seven sites. The occupancy factors of the individual sites have been refined by least-squares methods under different constraints. Bernal and Fowler’s ice rule is obeyed in the H-bonded water layers, and the water molecules of crystallization scarcely dissociate at all. The crystal structure has been redetermined by the X-ray diffraction method at 209 and 223 K, using an SnCl2·2H2O single crystal. No distinct change in the structure of non-hydrogen atoms has been disclosed on passing through the transition point (Tt=218 K). However, in the close vicinity of Tt, the a and c lattice parameters and the three H-bonded O···O distances steeply change in association with the ordering of the hydrogen atoms.
Infrared and Mossbauer Spectra of Synthetic Garnets A3Fe2Si3O12 (A: Mn, Cd, Ca)
Authors: Nishizawa Hitoshi , Shimada Masahiko , Matsuoka Kiyoshi , Koizumi Mitsue
Published: July 2006

The garnet Mn3Fe2Si3O12 with a0=11.821 Å was synthesized at high pressure and temperature. Infrared and Mossbauer spectra of the synthetic garnets A3Fe2Si3O12 (A: Mn, Cd, Ca) suggest that the distortion of SiO4 tetrahedra in these garnets increases and that of FeO6 octahedra decreases with increase in the radius of eight fold coordinated cation.
Studies of Electrode Processes of Oxovanadium (IV). IV. Catalytic Reduction of Acetylacetone Coupled with Cathodic Reduction of Bis(acetylacetonato)oxovanadium(IV)
Authors: Kitamura Mitsutaka , Sasaki Kazuo , Imai Hideo
Published: July 2006

Acetylacetone was catalytically reduced in the course of the electrolytic reduction of bis(acetylacetonato)oxovanadium(IV) at a mercury cathode. In acetonitrile solutions the catalytic reduction proceeded at −2.1 V vs. Ag/0.01 mol dm−3 AgClO4 electrode and the reduction products were hydrogen and acetylacetonate anion, while by the direct electrolysis of acetylacetone at −2.5 V a product with vicinal hydroxyl groups was formed. A steady-state current was observed in the controlled potential electrolysis. A reaction mechanism involving the regeneration of trivalent vanadium by the coupled chemical reaction of divalent vanadium with acetylacetone is proposed.
A Spectrophotometric Study of Phosphomolybdenum Blue Formed by the Reaction of Phosphate with a Mixture of Molybdenum(V) (Mo2O42+) and Molybdenum(VI) and Application to the Spectrophotometric Determination of Small Amounts of Phosphates
Authors: Ohashi Kousaburo , Yasu Kumiko , Suzuki Choutaro , Yamamoto Katsumi
Published: July 2006

The spectrophotometric determination of trace amounts of phosphates, based on the color development of phosphomolybdenum blue formed by the reaction of phosphate with a mixture of molybdenum(V) (Mo2O42+) and molybdenum(VI), is described. The rates of formation of phosphomolybdenum blue were measured at 25°C in a perchloric acid medium. The maximum constant color development was obtained in the perchloricacid range from 0.20 to 0.41 M under given conditions by warming the solution for 10 min at 80°C. The method obeys Beer’s law in the phosphate-concentration range from 0.08 to 1.16 μg/ml. The molar absorptivity at 840 nm was calculated to be 2.4×104 1 mol−1 cm−1. The rate is inverse fifth-order with respect to the perchloric-acid concentration in the range from 0.20 to 0.41 M and is first-order with respect to the molybdenum(V) concentration. The formation rates increase with the phosphate and molybdenum(VI) concentrations, although the rate dependence on the concentrations of these reactants is complicated. The ratio of P: Mo(V) for phosphomolybdenum blue was determined to be 1 : 1 using the molar-ratio method.