bluuebunny/crossref_metadata_2025 huggingface dataset:
Desorbability of Chemisorbed Water on Metal Oxide Surfaces. I. Desorption Temperature of Chemisorbed Water on Hematite, Rutile and Zinc Oxide
Authors: Morimoto Tetsuo , Nagao Mahiko , Tokuda Fujiko
Published: July 2006

The desorbability of water molecules chemisorbed on the surfaces of metal oxides has been investigated in the cases of α-Fe2O3, TiO2 (rutile) and ZnO. Water vapor adsorption isotherms were determined on the samples treated at various temperatures in a vacuum of 10−5 Torr. The BET Vm-values of water adsorption were plotted against the temperature of the pretreatment. The curves obtained show a sharp increase at a moderate temperature which is varied by the nature of solid substance. This fact makes us conclude that, at this temperature, the chemisorbed water on oxide surfaces starts to be removed. The variation in the desorption temperature due to the nature of metal oxide is considered to come from the magnitudes of the bonding force of the surface hydroxyl groups to the surface metal atoms on each solid.
The Crystal and Molecular Structure of 1,1′-Bis(pentamethyldisilanyl)-ferrocene,(π-C5H4Si(CH3)2Si(CH3)3)2Fe)
Authors: Hirotsu Ken , Higuchi Taiichi , Shimada Akira
Published: July 2006

Crystals of 1,1′-bis(pentamethyldisilanyl)ferrocene, (π-C5H4Si(CH3)2Si(CH3)3)2Fe, are monoclinic, with a=6.84, b=30.87, c=12.67 Å and β=96.80°. The space group is P21/n and there are four molecules in a unit cell. The structure was solved by Patterson and minimum functions, and further refined by Fourier and difference syntheses, and finally by a least-squares method. The final R value is 14.4% for 883 observed reflections. The two cyclopentadienyl rings are planar, approximately parallel to each other, separated by 3.28Å and deviated by about 6° from the fully eclipsed configuration. The molecular configuration is gauche with respect to the two side-chains. The mean values of the bond distances are found to be Fe–C(cyclopentadienyl rings)=2.05, C–C=1.45, C(cyclopentadienyl rings)–Si=1.87, C(methyl groups)–Si=1.90 and Si–Si=2.34 Å. All intermolecular separations correspond to the normal van der Waals interactions.
An Experimental Study on the Faradaic Impedance of an Electrode Process with a Preceding Chemical Reaction
Authors: Matsuda Kiyoshi , Tamamushi Reita
Published: July 2006

The frequency dependence of the faradaic impedance and its phase angle of an electrode process with a preceding chemical reaction was studied with the Cd(II)-EDTA system. The experimental results were analyzed by means of Smith’s equation, and the rate constant of the reaction, Cd2++HY3−→CdY2−+H+, was estimated to be equal to 2·3×109  l mol−1 sec−1 at the ionic strength of 0.5 and at 25°C. In connection with this study, the faradaic impedance behavior of simple electrode processes was re-examined with the Cd(II)-, Pb(II)-, and Zn(II)-KC1 systems.
Kinetics of Electron-transfer Reactions Involving Ethylenediaminetetra- acetatochromate(II) Ions as Reductants. I. Reactions with Some Isothiocyanatoammine Complexes of Chromium(III)
Authors: Ogino Hiroshi , Tanaka Nobuyuki
Published: July 2006

Kinetics of electron-transfer reactions of ethylenediaminetetraacetatochromate(II) ions with some isothiocyanatoammine complexes of chromium (III), Cr(NCS)n(NH3)6−n(3−n)+(n=0, 1,4 and 6) have been studied. The former ions are present in the forms of both CrII(H2O)edta2− and CrII(H2O)Hedta−, but the reaction of CrII(H2O)Hedta− with Cr(NCS)n(NH3)6−n(3−n)+ is not significant in the pH range from 3.6 to 5.3. Second-order rate constants (l mol−1sec−1) of the reactions between CrII(H2O)edta2− and Cr(NCS)n(NH3)6−n(3−n)+ at ionic strength 1.0 and 25°C are <10−2 Cr(NH3)63+, 0.2 for CrNCS(NH3)52+, 2.3 for Cr(NCS)4(NH3)2−, and 28.2 for Cr(NCS)63−.
A Study of Unnatural Amino Acids and Their Peptides. III. The Syntheses of Dl-β-(2-Pyridyl)-α-alanine and Its Peptides
Authors: Watanabe Hiroshi , Kuwata Shigeru , Naoe Kenzo , Nishida Yoshiteru
Published: July 2006

Dl-β(2-Pyridyl)-α-alanine has been synthesized in a good yield by the condensation of α-picolyl chloride and diethyl acetamidomalonate and by the subsequent hydrolysis of the product. The N-carbobenzoxy derivative of this amino acid, quite different from 3-pyridylalanine reported by Griffith and Harwood, could easily be prepared in a good yield. Only the carbodiimide method and the N-bromosuccinimide method proved to be successful in bringing the N-carbobenzoxylated amino acid into a peptide-coupling reaction with an amine component. Other methods, i. e., the mixed anhydride method, the azide method and the p-nitrophenyl ester method, were unsuccessful. It is noteworthy that, in the former cases, the activation of the carboxyl group occurs in situ in the presence of an amine component. No difficulties were encountered in the coupling reaction of the alkyl ester of this amino acid with usual N-protected amino acids. The alkaline hydrolysis of the protected dipeptide ester afforded the N-protected peptide in a good yield. The catalytic hydrogenation could be used to remove the benzyl ester group as well as the carbobenzoxy group without any damage to the pyridine ring. Decarbobenzoxylation also proceeded smoothly with hydrogen bromide in acetic acid.
Synthetic Reactions by Complex Catalysts. IX. Reaction of Thiol with Isocyanide
Authors: Saegusa Takeo , Kobayashi Shiro , Hirota Kiwami , Okumura Yoshiharu , Ito Yoshihiko
Published: July 2006

The reaction of a thiol with an isocyanide proceeds in two directions. In the first reaction (course a), the carbon atom of isocyanide with lone-pair electrons is inserted into the sulfur-hydrogen bond of thiol to produce thioformimidate (I). In the second reaction (course b), isothio-cyanate (II) and the alkane (III) from the alkyl group of thiol are formed. The proportion of the participation of two reactions depends upon the alkyl group of thiol and upon the reaction conditions including whether or not a catalyst is employed. Primary thiol prefers course a to course b, whereas tertiary thiol prefers course b. In the reactions at 15°C, the Group IB and IIB metal compounds, e. g., copper compounds, catalyzed the course a reaction preferably. At higher temperatures, e. g. at 100°C, thiol reacts with isocyanide quite rapidly, even in the absence of a catalyst. However, the catalyst effect favoring course a is seen even in the high-temperature reactions. The mechanism of the reaction, especially course b, has been discussed. Syn-anti structures of thioformimidate were also studied by NMR.
Studies of Heteroaromaticity. IX. Stability and Reactivity of 5-Nitro-2-furyl Diazo Compounds
Authors: Sasaki Tadashi , Eguchi Shoji , Kojima Atsuyuki
Published: July 2006

(5-Nitro-2-furyl)diazomethane (2), 3-(5-nitro-2-furyl)diazopropene (4), and 1-(5-nitro-2-furyl)diazoethane (6) were prepared by the oxidation of the corresponding hydrazones with active manganese dioxide. The relative stabilities of these diazo compounds were then compared with p-nitrophenyldiazomethane in their ethanolic solutions and in their solid states by measuring their decomposition rates spectroscopically; it was found that the stability decreased in the following order:

2& 6\backsimeqp-nitrophenyldiazomethane>2\backsimeq4 & & in ethanol

& p-nitrophenyldiazomethane>2>4>6 & & in the solid state.

The reactivities of these diazo compounds were also investigated in the decomposition reactions; the thermal and photolytic decomposition of 2 afforded l,2-di(5-nitro-2-furyl)ethylene (7) in a low yield, but 4 cyclized readily to 3-(5-nitro-2-furyl)pyrazole (8) in a good yield and 6, to an azine (9) even upon standing at room temperature. 2 was treated with benzoic acid in ether to give 5-nitro-2-furfuryl benzoate (10) in a quantitative yield, and with triphenylphosphine in the same solvent to afford the triphenylphosphazine (13) in a 75% yield; this last substance liberated nitrogen very easily in the presence of cuprous ions to give the phosphonium ylid (14), one of the Wittig reagents. 14 was then considered as a possible starting material for preparing (5-nitro-2-furyl)ethylenic compounds. Similarly, 3-(5-nitro-2-furyl)acrolein triphenylphosphazine (17) was prepared from 4 and triphenylphosphine.
Photoreduction of Azoxybenzene to Azobenzene
Authors: Tanikaga Rikuhei
Published: July 2006

The photochemical reduction of azoxybenzene to azobenzene has been investigated. The direct irradiation of azoxybenzene leads to a rearrangement to 2-hydroxyazobenzene and to cis-trans isomerization, whereas the sensitized irradiation leads to a reduction to azobenzene in the presence of a sensitizer with a triplet excitation energy greater than ca. 62 kcal/mol. 2-Hydroxyazobenzene and cis-azoxybenzene seem to be formed from the excited singlet state of azoxybenzene, and azobenzene, from the excited triplet state. Even without a sensitizer, the irradiation of benzo[c]cinnoline N-oxide, which is incapable of undergoing rearrangement or isomerization, brings about a photochemical reduction, which is affected by a sensitizer or a quencher, and also by the hydrogen-donating ability of the solvent used (isopropanol>ethanol>cumene>toluene). Acetone is yielded when isopropanol is used as the solvent. On the basis of these results, a mechanism in which benzo[c]cinnoline is formed from the excited triplet state of benzo[c]cinnoline N-oxide, followed by hydrogen abstraction from a solvent, is proposed.
Cationic Polymerization of Formaldehyde in Liquid Carbon Dioxide. IV. A Kinetic Study of the Polymerization in the Presence of Acetic Anhydride
Authors: Yokota Hisao , Kondo Masatsune , Kagiya Tsutomu , Fukui Kenichi
Published: July 2006

The influence of acetic anhydride on the polymerization of formaldehyde, which was carried out by means of initiation with an acidic catalyst in liquid carbon dioxode, was studied at 20 to 40°C. Acetic anhydride decreased the polymer yield and the degree of polymerization of the polymer resulting from the polymerization with acetic acid. Moreover, the over-all rate of polymerization with acetic acid in the presence of acetic anhydride deviated from a first-order equation with respect to the monomer concentration. On the other hand, the polymerization which was initiated by dichloroacetic acid was not affected by the presence of acetic anhydride. On the basis of a kinetical consideration, it can be said that the termination which was proportional to the square of the concentration of the initiating species was caused by the presence of acetic anhydride in the polymerization with acetic acid. The rate constants and the activation energies of the elementary processes were estimated, and a rate equation satisfying the experimental results was presented.
Initiation and Propagation in the Copolymerization of N-Phenylethylenimine with β-Propiolactone
Authors: Kagiya Tsutomu , Kondo Tomizo , Fukui Kenichi
Published: July 2006

In the copolymerization of N-phenylethylenimine with β-propiolactone, the mechanisms of the initiation and propagation reactions were investigated. The rate of the copolymerization was markedly increased by the addition of propionic acid. When a mixture of triethylamine and propionic acid was used as additive, the rate decreased with an increase in the amount of triethylamine, while with an equimolar mixture the rate was almost equal to that without any catalyst. No polymer was obtained with an excess of triethylamine. With Brönsted acid, the composition of the copolymer was independent of the concentration of the catalyst, but it varied with the pKa value. The monomer reactivity ratio of N-phenylethylenimine increased with a decrease in the pKa value. While that of β-propiolactone decreased.
Ring-opening Polymerization of the Macrocyclic Ester
Authors: Yoda Kentaro , Kimoto Kazuyuki
Published: July 2006

The ring-opening polymerization of cyclic bis(ethylene isophthalate) (I) was carried out in the presence of various metallic compounds as catalysts. Among the polycondensation catalysts for ethylene terephthalate, antimony and tin compounds were very effective in the ring-opening polymerization of I. On the other hand, titanium, zinc, calcium, and aluminum compounds did not show high catalytic activity. The polymerization of I proceeded even at temperatures below the melting point of I. As the melting point of the resulting poly(ethylene isophthalate) was much lower than the polymerization temperature, the reaction system gradually melted in consequence of the progress of the polymerization reaction.
Aluminum Silanolates Acid Strength and Polymerization Catalyst Activity
Authors: Saegusa Takeo , Ueshima Takashi , Kato Kunioki
Published: July 2006

Two aluminum silanolates, diethyl(trimethylsiloxy)aluminum (I) and tris(trimethylsiloxy)-aluminum (II), were compared with the corresponding aluminum alcoholates in terms of their acid strength and in their catalyst behavior in the polymerizations of cyclic ethers and vinyl ether. The reference aluminum alcoholates were diethylaluminum t-butoxide (III) and aluminum t-butoxide (IV). The Lewis acid strength was examined by means of two methods, the Hammett indicator method and the shift of the IR carbonyl band (ΔνC=O) of n-butyraldehyde. Four aluminum compounds, I–IV, were weaker Lewis acids than triethylaluminum; i.e., the replacement of the ethyl group of triethylaluminum with either a siloxy group or an alkoxy group brought about a decrease in the acid strength. The acid strength of I and II were demonstrated to be stronger than that of the reference alcoholates, III and IV. A difference in polymerization catalyst activity was also observed between aluminum silanolates and the reference alcoholates; it was reasonably explained by the difference in acid strength.
Copolymerization of N-Phenylethylenimine and β-Propiolactone
Authors: Kagiya Tsutomu , Kondo Tomizo , Narisawa Shizuo , Fukui Kenichi
Published: July 2006

The copolymerization of N-phenylethylenimine and β-propiolactone was carried out at 0°C in an acetonitrile solution. N-Phenylethylenimine and β-propiolactone copolymerized without any catalyst to give a powdery or a resinous polymer. From the results of a study of the infrared spectrum, X-ray diffraction, differential thermal analysis, and hydrolyses of the copolymer, it was concluded that the homopolymerization of neither monomer took place, and that the copolymer contained the ester structure of (Remark: Graphics omitted.)-in the main chain. The monomer reactivity ratios of N-phenylethylenimine (r1) and β-propiolactone (r2) were estimated to be r1=7.5 and r2=0.15.
Dynamic Mechanical Behaviour of Organic Molecular Crystals. II. Elastic Constants of Single-Crystal Anthracene
Authors: Danno Takaaki , Inokuchi Hiroo
Published: July 2006

The thirteen elastic constants, Cij, and the elastic compliances, sij, of monoclinic single-crystal anthracene were determined from sound velocities measured by the ultrasonic pulse method at room temperture. The observed elastic constants were C11=8.92, C12=4.63, C13=4.49, C15=−2.58, C22=13.8, C23=8.45, C25=−2.59, C33=17.0, C35=−2.88, C44=2.42, C46=1.14, C55=2.84 and C66=−3.16 (in units of 1010 dyn/cm2). The hydrostatic linear compressibilities, β, of the anthracene molecular crystal were then calculated from these elastic constants and compliances; the β along [100] was 12.7×10−12 cm2/dyn, β[010]=4.41×10−12 cm2/dyn, and β[001]=3.59×10−12 cm2/dyn.
Infrared Spectrum of Deoxyribonucleic Acid —Effects of Base Composition and of 15N-Substitution—
Authors: Tsuboi Masamichi , Shuto Katsuichi , Higuchi Shigesada
Published: July 2006

Infrared absorption spectra have been observed in the 4000–500 cm−1 region of deuterated and undeuterated films of deoxyribonucleic acids (DNA’s) obtained from Micrococcus lysodeikticus (guanine plus cytosine content or GC content 72%), from Bacille de Calmette-Guérin (GC 65%), from Pseudomonas aeruginosa (GC 65%, 15N-substituted), from calf thymus (GC 44%), and from Cancer borealis (GC 3%). Of the undeuterated DNA, 14 absorption bands have been assigned to the GC pair and 17 absorption bands to the adenine-thymine (AT) pair. Of the deuterated DNA, 19 absorption bands have been assigned to the GC pair and 16 to the AT pair. For 4 bands of undeuterated DNA and 13 bands of deuterated DNA, appreciable 15N isotopic shifts have been observed. A discussion has been given of a few of these bands on the basis of the observed 15N shift and some other data.
Rheological Properties of Hydrogels of Agar-agar. III. Stress Relaxation of Agarose Gels
Authors: Watase Mineo , Arakawa Kiyoshi
Published: July 2006

A stress relaxation experiment on hydrogels of agarose isolated from agar-agar was made by means of a chainomatic balance relaxometer for the purpose of investigating the mechanism of gelation. The measurements were made on the agarose gels of the concentration range from 1.2 to 2.0 wt%, and also on agar-agar gels for the comparison, at various temperatures from 25 to 55°C. The relaxation curves obtained were represented approximately by a mechanical model consisting of three Maxwell models in parallel. The apparent activation energy, ΔH, which was calculated from the temperature dependence of the longest relaxation time, τ1 was about 5 kcal/mol for all gels treated in this study, which was nearly the same magnitude as that for agar-agar gels. It was observed in the curves obtained that the relaxation curves for agarose gels had quite similar characteristics to those for agar-agar gels of the same concentration and was observed that the total instantaneous modulus of the former gels amounted to about 80% of that of the latter gels. From these results it may be concluded that agarose is a main constituent in the network structure in agar-agar gels and that the hydrogen bonding plays a major role in the agar-agar gels as well as in the agarose gels.
The Bromination of Tris(3-phenyl-2,4-pentanediono)cobalt (III)
Authors: Murakami Yukito , Nakamura Katsuyuki
Published: July 2006

Tris(3-phenyl-2,4-pentanediono)cobalt(III) has been treated with three kinds of bromination reagents; bromine in the presence of pyridine, pyridine perbromide, and N-bromosuccinimide. Components of the product species have been detected by means of thinlayer chromatography and fractionated by liquid-chromatography. The characterization of bromination products has been performed by the aid of infrared and nuclear magnetic resonance spectroscopy. The bromination has taken place with the chelate ring remaining intact, and converted methyl groups in the coordinated ligands to bromomethyl. The cleavage of coordinate bonds, which has occurred afterward, has resulted in the formation of a metal-absent brominated ligand. Among various bromination products, the one with lowest bromination degree (monobrominated chelate) has been fully characterized in accordance with the experimental facts: elemental analysis, the appearance of a new infrared band at 1248 cm−1 which is attributable to CH2 wagging vibration of the CH2Br group, and two doublet NMR peaks at 3.55, 3.69, 3.94 and 4.09 in δ-value which are due to nonequivalent protons of the CH2Br group. Reaction mechanism has been discussed in terms of electrophilic substitution process.
Intramolecular Hydrogen Bonds. XII. The Dipolar-field and the Hydrogen-bonding Effects of the Hydroxyl Group on the Carbonyl Frequencies of Aliphatic Hydroxy-carboxylates
Authors: Mori Nobuo , Asano Yuzuru , Tsuzuki Yojiro
Published: July 2006

The infrared carbonyl-stretching absorption bands of several methoxy- and hydroxyalkanoates have been measured in dilute carbon tetrachloride solutions, and their frequency shifts from the normal bands of ethyl alkanoates have been explained in terms of the dipolar-field and the hydrogen-bonding effects of the substituents. Further, as regards the direction of hydrogen bonding, the spectral data of the hydroxy-esters lead to essentially the same conclusion as that based on their hydroxyl spectra. However, the magnitudes of the carbonyl-frequency shifts due to hydrogen bonding can not be related to those of the corresponding hydroxyl shifts.
Condensation Reaction of Ferrocene with Carbonyl Compounds
Authors: Shiga Mikio , Motoyama Izumi , Hata Kazuo
Published: July 2006

The condensation reactions of ferrocene with various ketones and with trichloroacetaldehyde in the presence of aluminum chloride were investigated. The formation of carbinol (7) as an intermediate was postulated in these reactions. In the reaction of acetone with ferrocene, the intermediate carbinol underwent further condensation with other ferrocene molecules to give oligomers (9). On the other hand, in the cases of methyl ethyl ketone, acetophenone, propiophenone, cyclohexanone, and trichloroacetaldehyde, the condensation reactions produced olefinic compounds via the intermediate carbinols. The intermediate carbinol was isolated together with the olefin in the reaction with trichloroacetaldehyde.
Hydrolysis of Uranium Monocarbide and Oxidation Potentials
Authors: Hori Yoshio , Mukaibo Takashi
Published: July 2006

The hydrolysis of UC with 1 n H2SO4 was carried out in the presence of various oxidants at 80°C. The amount of gaseous products was measured by means of a gas chromatograph; the dissolved, carbon-containing compounds, and the insoluble residues produced in the reaction were analyzed for carbon. Analyses of the uranium and oxidants consumed were also made by volumetric and gravimetric methods. The results may be summarized : (1) The hydrolysis of UC with 1 n H2SO4 proceeds by an electro-chemical mechanism. (2) The hydrolysis products fundamentally depend upon the oxidation potential of the oxidants in the solution. (3) The oxidation potential at which the hydrolysis of UC with 1 n H2SO4 proceeds can be explained in terms of the partial ionic character of UC. (4) The application of this experimental method to other carbides would serve to clarify the chemical reaction and the bond character of the carbides.
ASMO-SCF-CI Calculation on the Electronic Structures of the Bases of Nucleic Acids with Special Emphasis on the Configuration Interaction
Authors: Fujita Hiroko , Imamura Akira , Nagata Chikayoshi
Published: July 2006

The calculation was carried out on the electronic structures of the bases of nucleic acids by means of semi-empirical self-consistent field configuration interaction (SCF-CI) method taking into account of the CI calculation. The effects of mixed configurations, e.g., doubly excited ones, on the transition energies and oscillator strengths, were remarkable. On the other hand, the effects on the direction of the transition moments and the π–electron densities were small. The more configurations were involved, the better the calculated data agreed with the experimental result, but the change of the calculated values with increasing number of configurations from twenty to thirty was small. The agreement between the calculated singlet transition energies and the observed ones obtained by the vapor spectra of the bases was satisfactory, when twenty or thirty configurations including doubly excited ones were considered. The direction of the transition moment calculated by the present authors for thymine agreed well with the experimental result by Stewart and Davidson. For adenine, the calculated direction of transition moment of the main band was polarized parallel to long-axis and it coincided not with the result obtained by Stewart and Davidson, but with that proposed by Mason. Variation of the core resonance integral exerted the influence on the electronic structures, and K in Eq. (1), viz., −0.49 was better than −0.431 when doubly excited configurations were taken into calculation.
Kinetics of Multidentate Ligand Substitution Reaction. III. Substitution Reactions of BT with Cobalt(II) and Nickel(II) Chelates of N-(2-Hydroxyethyl)-ethylenediamine-N,N′,N′-triacetic Acid and 2,2′-Ethylenedioxybis[ethyliminodi(acetic acid)]
Authors: Kodama Mutsuo , Sasaki Chifumi , Noda Tomohiko
Published: July 2006

BT can displace EDTA-OH and GEDTA from their cobalt(II) and nickel(II) chelate as in the case of the substitution reaction of BT with cobalt(II)-EDTA chelate or nickel(II)-EDTA chelate. In this paper, kinetics of the substitution reactions of BT with cobalt(II)- and nickel(II)-chelates of EDTA-OH and of GEDTA was studied spectrophotometrically. All substitution reactions were found to be first-order in BT and first-order in metal(II)-chelate of EDTA-OH or GEDTA, and to proceed through two simultaneous reaction paths analogous to those proposed for the substitution reaction of BT with cobalt(II)-EDTA chelate. Although EDTA-OH differs from EDTA by the presence of a hydroxyethyl group in place of one acetate group, its metal(II) chelate behaves in a nearly identical manner with EDTA chelate in the substitution reaction and the cleavage of the metal-nitrogen bond of the glycinate group is considered to be the probable rate-determining step. The substitution reactions of BT with GEDTA chelates are considered to be more favored thermodynamically over the reactions of EDTA-OH chelates, but were found to be less favored kinetically. This fact may suggest that the geometrical structure of metal(II)-GEDTA plays an important role in determining the rate of the substitution reaction of GEDTA.
Studies of the Grinding of Condensed Phosphates. IV. Grinding of Sodium Trimetaphosphate at Low Pressure
Authors: Motooka Itaru , Hashizume Genzo , Kobayashi Masamitsu
Published: July 2006

The change in sodium trimetaphosphate by grinding at low pressure was examined by the X-ray diffraction method and paper chromatography. The crystalline sodium trimetaphosphate became amorphous more rapidly when ground at low pressure than in dry air or nitrogen gas, and in these cases the chain phosphates higher than triphosphate were produced in addition to ortho-, pyro- and tri-phosphates.
Syntheses and Properties of Some Tetrabromobis(dithioacetylacetonato)Complexes
Authors: Furuhashi Akiko , Takeuchi Toshio , Ouchi Akira
Published: July 2006

Some compounds of type M(Lss)2Br4, where M is Mn(II), Fe(II), Co(II), Cu(II), Zn(II) and Cd(II) and HLss are dithioacetylacetone, were obtained by passing hydrogen bromide, adding bromine and passing hydrogen sulfide through an ethanolic solution containing an anhydrous metal bromide and acetylacetone. Such compounds, which seem to be isostructural with tetrachlorobis-(dithioacetylacetonato)iron(II), are stable. They are all of high spin, and their infrared spectra show characteristic bands at about 1200, 1000 and 860 cm−1. CuI(Lss)2Br3 was also obtained from cupric bromide by the same method without using bromine, but from cupric chloride, an isostructural complex was not obtained but [Cu(C5H8S2)Cl]n. Electronic spectra are also shown and discussed.
Studies on Coprecipited Phases in the Calcium-Gadolinium Oxalate System
Authors: Chi Hsiu , Nagashima Kozo
Published: July 2006

Calcium oxalate is often used as a carrier for precipitating rare earth elements. Gadolinium was chosen as a rare earth element and X-ray powder diffractometry used for the identification of coprecipitated solids. The X-ray lattice spacings are tabulated for each of the coprecipitates of varying composition in the calcium-gadolinium oxalate system. From the spacings, the following facts were obtained: (1) The uptake mechanisms of gadolinium in calcium oxalate, and calcium in gadolinium oxalate are completely due to the formation of solid solutions. (2) Several new solid solution phases were formed. (3) When the gadolinium to calcium ratio is proper, precipitates having a weddellite structure, which is not obtained in usual analytical procedures, are formed.
Structure and Properties of the Condensation Product of 2-Amino-3-ethoxycarbonyl-1-azaazulene and Formamide
Authors: Nozoe Tetsuo , Seto Shuichi , Toda Takashi
Published: July 2006

The structure of the condensation product of 2-amino-3-ethoxycarbonyl-1-azaazulene and formamide is proved not to be the expected cyclohepta[2,3]pyrrolo[5,4-d]pyrimidine derivative, but 5,6-pentamethylene-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-one. The chemical properties of the obtained pyrrolo-pyrimidine are investigated, and then the tautomerism of the above compound is discussed.
Polar Conjugative Effect of Aryldithia Group on the Dissociation and Ultraviolet Spectra of Substituted Phenols
Authors: Oae Shigeru , Yoshihara Masakuni
Published: July 2006

A few substituted aryldithiaphenols have been synthesized and their acid dissociations, NMR chemical shifts and UV spectra have been determined. The relatively stronger acidic nature of p-aryldithiaphenols over that of the meta-isomers is interpreted as being caused by the 3d-orbital resonance effect of the aryldithia group.
The Formation and Reactions of α-Keto Sulfoxide
Authors: Kumamoto Takanobu , Mukaiyama Teruaki
Published: July 2006

The reactions of α-keto sulfoxide, produced by the oxidation of thiolester, were studied. It was established that the oxidation of S-ethyl thiobenzoate with N-bromosuccinimide and isopropyl alcohol afforded benzoyl ethyl sulfoxide. Similarly, butyryl ethyl sulfoxide was produced by the oxidation of S-ethyl thiobutyrate with iodosobenzene. α-Keto sulfoxide, produced by the above-mentioned oxidations, reacts with alcohols, phenols, amines or sodium carboxylates to afford acylated products such as esters, amides or carboxylic anhydrides in good yields.
Ring-butylamination of Toluquinone: Isolation of Products by TLC and an Observation of Their Reaction Course on the Basis of Molecular Reactivity Index
Authors: Kumanotani Ju , Kagawa Fumio , Hikosaka Aizo , Sugita Kazuyuki
Published: July 2006

The ring-butylamination of toluquinone with n-butyl-amine was carried out in a chloroform or ethanolic solution at room temperature or at 25.0°C with various molar ratios of the quinone to the amine (designated as Q/A). For the successful separation of each product, TLC was applied, while polarography was used for following the change in the composition of the reacting mixture as well as for measuring the amount of the amino-quinone separated from the reacting mixture by TLC. In the butylamination of toluquinone with excess butylamine (Q/A: 1/5) for 10 hr, the major products were 3,6-bis-(n-butylamino)-toluquinone (32%) and 2,5-bis(n-butylamino)-p-benzoquinone (8%), accompanied by a relatively large amount of unknown by-products: with a Q/A of 2/1 for 2 hr, the major products were 3- and 4-n-butylamino-toluquinone (17% and 21%) and 3,6-bis(n-butylamino)-toluquinone (3.3%) together with toluhydroquinone (47%). The quantitative formation of 3,6-bis(n-butylamino)-toluquinone from 3-n-butylamino-toluquinone or the formation of 2,5-bis(n-butylamino)-p-benzoquinone (34%) and 3,6-bis-(n-butylamino)-toluquinone (1%) from 4-n-butylamino-toluquinone was also found (Q/A: 1/4, 3 hr or 13 hr), where a faster reaction was found for the 3-isomer than for the 4-isomer under the present conditions. The pathway of the formation of each product was discussed on the basis of the calculated reactivity index of toluquinone or its butylaminated toluquinone isomers toward the amine-attacking.
Photochemical Rearrangement of Azoxybenzene to 2-Hydroxyazobenzene and cis-trans Isomerization
Authors: Tanikaga Rikuhei
Published: July 2006

The photochemical oxygen migration and cis-trans isomerization of azoxybenzene have been investigated. The direct irradiation of trans-azoxybenzene leads to both rearrangement to 2-hydroxyazobenzene and cis-trans isomerization, whose rate is faster in a polar protic solvent and is never affected by a quencher. Direct irradiation does not afford any azobenzene formed from an excited triplet state of azoxybenzene. On the basis of these observations, the author proposes a mechanism in which 2-hydroxyazobenzene and cis-azoxybenzene are formed directly from an excited singlet state of trans-azoxybenzene. This mechanism is analogous to that for the photochemical rearrangement of nitrone to oxaziridine. Nitro- or dimethylamino-substituted azoxybenzene undergoes neither photochemical rearrangement nor cis-trans isomerization. Oxygen migration is not sterically hindered by a substituent in the 3-position of azoxybenzene.
Medium-Sized Cyclophanes. VI. High-Temperature NMR Spectra of [2.2]Metacyclophane and Optical Resolution of 4,14-Disubstituted Derivatives
Authors: Sato Takeo , Akabori Sadatoshi , Kainosho Masatsune , Hata Kazuo
Published: July 2006

The NMR spectra of [2.2]metacyclophane have been shown to be held unchanged over a wide range of temperature, ca. −80 to 190°C, indicating that the ten-membered ring system undergoes no inversion and is frozen in a chair conformation. It may, then, be expected that suitably substituted derivatives of [2.2]metacyclophane would become disymmetric due to restricted inversion; such was proved to be the case by carrying out the optical resolution of the 4, 14-di-substituted derivatives. The 4,14-dimethyl derivative was resolved by means of a complex formation with Newman’s reagent, [α]57826=−3.4 and +4.2°. 4,14-Dicarboxylic acid was also resolved by converting it to the quinine salt, [α]d22=+5.0°.
Oxygen Oxidation of Ferrous Ions Induced by Chelation
Authors: Kurimura Yoshimi , Ochiai Ryoji , Matsuura Niro
Published: July 2006

The oxidation of ferrous ions by dissolved oxygen in aqueous solutions in the presence of such chelating agents as EDTA, DTPA, EDTAOH, EDTP, CyDTA and NTA was studied spectrophotometrically. The rate equation for the oxidation reaction is:

d[Fe^III]/dt=4k_p[Fe^IIHZ][O_2]+4k_n[Fe^IIZ][O_2]

where kp is the rate constant for the (1) reaction; kn, the rate constant for the (2) reaction; FeIIHZ, protonated chelate, and FeIIZ, the normal chelate.

&Fe^IIHZ+O_2\xrightarrowk_pFe^IIIZ+HO_2 \labeleq1

&Fe^IIZ+O_2\xrightarrowk_nFe^IIIZ+O_2^-\labeleq2

The linear relationship between log k and log Rf shown by Eq. (3), was obtained from all the experimental results except for those on the EDTPA and CyDTA systems:

logk=0.92+0.13logR_f\labeleq3

In Eq. (3), k is 4kp and Rf is KFeIIIL⁄KFeIIHL, for the protonated chelate, while k is 4kn and Rf is KFeIIIL⁄KFeIIL for the normal chelate. In the cases of the DTPA and CyDTA systems, a deviation from the straight line was observed. This can be explained by steric hindrance of the oxygen attack by these chelates.
An Energetic Consideration of the Monomer Reactivity in Catalytic Polymerization
Authors: Kagiya Tsutomu , Sumida Yūzō , Nakata Tetsuya
Published: July 2006

The elementary processes constituting the polymerization reaction are energetically considered, and the relation between the activation energy of each process and the structures of reagents or the kind of solvents is theoretically discussed. The solvation energy of ion has been evaluated with the ionization potential of anion or the electron affinity of cation, and the ionization potential or the electron affinity of the growing radical with that of the corresponding monomer. The energy of the highest occupied (εho=α+λhoβ) or the lowest vacant (εlv=α–ηlvβ) π level of the monomer has been calculated, and the π bond dissociation energy has been evaluated with the summation (λho+ηlv). On the basis of these considerations, the monomer reactivity in catalytic polymerization can be compared with the relative magnitude of the electronic natures of monomer and components of catalyst, i. e., ionization potential or electron affinity.
Nuclear Magnetic Double-resonance Study of the Hindered Internal Rotation in Formamide
Authors: Kamei Hirotake
Published: July 2006

The nitrogen-14 quadrupole relaxation broadening effect on the proton spectrum of formamide was eliminated by a 1H–{14N} double resonance technique. The completely-decoupled proton spectra of formamide in the neat liquid and in acetone, dioxane, and water solutions were observed at several temperatures. The spectra observed at room temperature were analyzed on the basis of an ABC system, while the spectra at higher temperatures (∼100°C) were analyzed on the basis of an AB2 system. From the changes in the resonance lines of the formyl proton with the temperature, the values of the activation energy for the hindered internal rotation about the C–N bond, Earot, and for the intermolecular proton exchange involving the amine protons, Eaex, were obtained. It has been found that the hydrogen-bond formation on the carbonyl oxygen of formamide increases the Earot value and the magnitude of the vicinal coupling constants, while it decreases the magnitude of the geminal coupling constant.
Photochemistry of Acetanilide. I. Quantum Yields of the Rearrangement and Benzene Photosensitized Reaction
Authors: Shizuka Haruo , Tanaka Ikuzo
Published: July 2006

The photochemical rearrangement of acetanilide under 2537 Å irradiation has been studied by spectrophotometry. The quantum yield of the rearrangement in cyclohexane solution was independent of the irradiation time, concentration of acetanilide, presence of oxygen and light intensity. It was found that electronic energy transfer from the electronically excited benzene to acetanilide occurred in the mixed solution, and the transfer mechanism was explained by singlet-singlet nonradiative energy transfer. It was observed that the energy transfer rate constant was about 22 times greater than that predicted by diffusion theory (the transfer rate constant, k3=1.45×1011  l·mol−1·sec−1). From these studies, it is proposed that the rearrangement of acetanilide is an introamolecular reaction and does not occur from the triplet state but from the lowest singlet excited state.
Synthetic Inorganic Ion-exchange Materials. XII. Some Observation on Surface Structure and Cation-exchange Behaviour of Three Different Antimonic Acids
Authors: Abe Mitsuo , Ito Takuji
Published: July 2006

The cation-exchange behaviour and surface functionality of three different antimonic acids, amorphous, glassy and crystalline, were studied by thermogravimetric measurement, infrared absorption spectrometry and change in uptake of potassium ions upon heating. The ion-exchange capacities of the amorphous and glassy antimonic acids decrease with the loss of chemically bonded water. In contrast, the capacities of the crystalline acid heated within 200°C rarely change because of the loss of the interstitial (free) water and no drastic change occurs in the surface structure of the crystal. The crystalline acid with free water removed adsorbs moisture upon exposure to the atomsphere at room temperature. Upon heating above 300°C, the tenaciously bonded water was removed and the cation-exchange capacity decreased simultaneously. The infrared absorption spectra indicated that the surface functionality of the crystalline acid, similar to that of crystalline sodium antimonate Na[Sb(OH)6], is different from those of the amorphous and glassy acids. It seems that chemically bonded water in the crystalline acid is tenaciously combined as Sb-OH.
Tensammetric Study of the Adsorption of Brucine
Authors: Kodama Mutsuo , Murata Mitsuko , Noda Tomohiko , Kimura Akiko
Published: July 2006

This paper will present two results of experiments concerning the adsorption of brucine. We will first discuss the adsorption of brucine on D. M. E. studied tensammetrically. Brucine was found to give a tensammetric wave with two peaks, at +0.10 V and −1.15 V vs. SCE. The positive tensammetric peak can be ascribed to the usual adsorption process. The second peak, however, behaved differently from the first, probably due to the reformation of adsorbed brucine film involving the protonation and the reorientation of brucine. Secondly, we will present experimental facts concerning the depressive effects of brucine on the reduction waves of copper(II).
The Kinetics of Substitution Reactions Involving Metal Complexes. XII. The Reactions between Copper(II) Ions and Zinc(II)-nitrilotriacetate Complexes
Authors: Tanaka Nobuyuki , Kimura Masaru
Published: July 2006

The kinetic study of the substitution reaction of copper(II) ions and zinc(II)-nitrilotriacetate complexes in acetate buffer solutions has been carried out with the same procedure as reported previously. The reaction was treated as to proceed through both hydrated metal ions and monoacetato complexes. The rate constants for eight elementary reaction paths, of which four involve the hydrated copper(II) ions and the others the monoacetatocopper(II) complexes, were determined at ionic strength 0.23 at 0°C. The values obtained indicate that all the reactions proceeding through hydrated copper(II) ions are faster than the corresponding reactions proceeding through monoacetatocopper(II) complexes.
A.C. Polarographic Determination of Lanthanum(III), Nickel(II), Calcium(II), and Magnesium(II) by Using Diethylenetriaminepentaacetic Acid as a Titrant
Authors: Kodama Mutsuo , Murata Mitsuko
Published: July 2006

The a.c. polarographic determination of lanthanum(III), nickel(II), calcium (II), and magnesium(II) with diethylenetriaminepentaacetic acid was studied by using a dropping mercury electrode and a hanging mercury drop electrode as indicator electrodes. Lanthanum(III) and nickel(II) in an acetate buffer solution and calcium(II) and magnesium(II) in an ammonia buffer solution could be titrated with diethylenetriaminepentaacetic acid in the concentration range from 5×10−5 to 1×10−3  m by measuring the height of the a.c. polarographic wave of diethylenetriaminepentaacetic acid after the end point. The effect of the presence of calcium-(II) ions on the a.c. polarographic determination of lanthanum(III) in an acetate buffer solution of pH 4.0 was also examined and discussed thermodynamically.
Formation Constants of Chromium(III) Complexes with (N, N)-, (O, O)- and (N, O)-Type Ligands, and Their Relationship to Structure
Authors: Takata Shichiro , Kyuno Eishin , Tsuchiya Ryokichi
Published: July 2006

Formation constants of chromium(III) complexes with β-alanine, anthranilic acid, picolinic acid and 8-hydroxyquinoline, being all (N, O)-type bidentate chelate ligands, were determined by the pH method at an ionic strength μ=0.1, and at 25°C. The formation constants are log k1=9.69 for β-alanine, log k1=4.35 and log k2=3.67 for anthranilic acid, log k1=4.76, log k2=4.38 and log k3=4.55 for picolinic acid and log k2=9.76 and log k2=8.48 for 8-hydroxyquinoline, respectively. The relationships between the formation constants of the complexes and the acid dissociation constants of the chelate ligands were discussed, including those for glycine and α-alanine complexes, and those, in addition, for the complexes with several (N, N)- and (O, O)-type ligands reported in a preceding paper.
Infrared-spectral Studies on the Orientation of the Lone Pairs in Piperidine Derivatives
Authors: Masamune Tadashi , Takasugi Mitsuo , Matsuki Minoru
Published: July 2006

The infrared spectra of stereoisomers of several piperidines and their N-methyl derivatives in carbon tetrachloride have been measured in the region of 3020 to 2500 cm−1. The estimated intensities (A) of their Bohlmann bands have been analyzed, provided that Formula (1) concerning the intensity defined in the text holds for the compounds examined. The result indicates that piperidine exists mainly, but not exclusively, in the conformation with the lone pair axial.
Acetonated Sorbofuranoses and Their Favored Conformations as Determined by Proton Magnetic Resonance Spectroscopy
Authors: Maeda Takashi , Tori Kazuo , Satoh Shiroh , Tokuyama Kanji
Published: July 2006

A series of l-sorbofuranose derivatives have been studied by PMR spectroscopy in order to determine their favored conformations from the coupling constants obtained by applying the spin-decoupling techniques and the solvent effects of benzene at 100 MHz. The coupling constants J3,4, have disclosed that the furanose ring of methyl 1,3,4,6-tetra-O-acetyl-α-l-sorbofuranoside (IIa) in solutions has a conformation close to a C3-endo-C4-exo half-chair, while that of its β-anomer (IVa) has a C3-exo-C4-endo half-chair conformation. Their conformations are unchanged over the temperature range of 32–74°C, but they are affected by the introduction of a 4,6-O-or 2,3-O-isopropylidene group, either of which locks the furanose ring to a C3-exo-C4-endo half-chair conformation. This effect is thought to play an important role in the exclusive formation of 2,3:4,6-di-O-isopropylidene-α-l-sorbofuranose (XII) during the acetonation of l-sorbose.
The Nephelauxetic Effect in Praseodymium(III) and Neodymium(III) Complexes
Authors: Misumi Seizo , Kida Sigeo , Isobe Toshiyuki , Inazumi Akio
Published: July 2006

The absorption spectra of praseodymium(III) and neodymium(III) complexes were measured in an aqueous alkaline solution with an excess of ligands. The experimental data being used, the Racah parameter, E3, and the Landè parameter, ζ4f, were calculated by the least-squares method on the assumption that the energy separation between J-levels of the 4fn-configuration is a function of E3 and ζ4f. The nephelauxetic effect in the Pr(III) and the Nd(III) complexes was then discussed by using the values of E3 thus obtained.
The Ultraviolet Absorption Spectrum of Quinazoline Vapor Due to the n–π* Transition
Authors: Hasegawa Yoshinori , Amako Yoshito , Azumi Hiroshi
Published: July 2006

The ultraviolet absorption spectrum of quinazoline vapor due to the n–π* transition was photographed and analysed. The lowest n–π* transition has its origin at 27581 cm−1, and consists of two strong and prominent progressions, 515 and 784 cm−1. The vibrational analysis of the strong bands is reported on.
Mass Spectrometry of Organometallics. I. Titanium Cyclopentadieny Complexes
Authors: Takegami Yoshinobu , Ueno Toru , Suzuki Toshimitsu , Fuchizaki Yuichi
Published: July 2006

The possibility of mass spectral analysis of less volatile and air sensitive organometallic compunds has been studied with an electron-impact, Muttauch-type mass spectrograph. Several organotitanium compounds, (C5H5)2Ti, (C5H5)2Ti-methylacetylene complex, (C5H5)2Ti-allylchlorideand (C5H5)2TiCl2-AlEt2Cl complex, have been subjected to mass spectral analysis, and the parent ion has been detected for each compound. The (C5H5)2Ti-methylacetylene complex gave a parent ion of (C5H5)2Ti(C3H4)2+; NMR and IR suggested the structure as a five-membered cyclic diene complex of (C5H5)2Ti. The (C5H5)2Ti-allylchloride gave a parent ion of (C5H5)2-Ti(C3H5)+ which proves the existence of allyl complex of (C5H5)2Ti. The (C5H5)2TiCl2-AlEt2Cl complex gave a parent ion of (C5H5)2TiCl2AlEtCl+ which is in agreement with the composition reported in the literature.
Studies of the Behavior of Trivalent Uranium in an Aqueous Solution. II. Absorption Spectra and Ion Exchange Behavior in Various Acid Solutions
Authors: Satô Akiko , Suzuki Shin
Published: July 2006

The absorption spectra of trivalent uranium in hydrochloric, sulfuric and perchloric acid solutions were investigated. It was found that there is a possibility of the formation of a chloro-complex from the fact that a large change in absorption spectra was observed at high concentrations of chloride ion. On the basis of the above facts, the behavior of trivalent uranium in those media toward ion exchange resin was studied. It was considered that an anionic complex of trivalent uranium begins to form at concentrations of hydrochloric acid above 7 n, which shows good agreement with results obtained on trivalent ions of plutonium, americium and curium, which are similar actinide elements. However, it was not possible to confirm the existence of a soluble carbonate complex of trivalent uranium, as in the case of trivalent plutonium or americium.
Studies on Adduct Formation of β-Diketone Chelates with Heterocyclic Bases
Authors: Shigematsu Tsunenobu , Tabushi Masayuki , Matsui Masakazu , Munakata Megumu
Published: July 2006

Stability constants of the 1:1-adducts with heterocyclic Lewis bases on copper chelates of six β-diketones and two ethylesters of β-ketoacids (Cu(ligand)2·base) were determined by spectrophotometric measurements in visible region and the effects of β-diketone substituents, Lewis bases and organic solvents on the stability constants were studied. Terminal alkyl groups of β-diketones hardly hindered the adduct formation, because the adducts of β-diketone chelates except acetylacetone chelate had similar stability constants. Solvent effect was due to the formation of the solvates of the chelates or the solvation of N-base with solvent. This is related to the abnormal position of chloroform in the order of the adduct stability compared with oxygencontaining solvents. Infrared spectra indicate that the metal-oxygen bonding, as well as the basicity of Lewis bases is considered as an essential factor in the adduct formation of metal β-diketone chelates.