bluuebunny/crossref_metadata_2025 huggingface dataset:
The Infrared Absorption Spectra of Nickel Metal Surfaces Modified with Optically Active α-Alanine from Its Aqueous Solution
Authors: Hatta Aritada , Moriya Yoshihiro , Suëtaka Wataru
Published: July 2006

The infrared absorption spectra of thin films of α-alanine formed on pure nickel and “Raney nickel” surfaces, modified with its aqueous solution, were measured by the high-sensitivity reflection method. From the infrared dichroism in the reflection spectra, the molecular orientations in the thin films were derived. In the thin film formed on pure nickel modified at 5 °C, the CO2− group of α-alanine is oriented nearly vertical to the metal surface and the O···O axis is inclined to the surface. On the other hand, when the “Raney nickel” film is modified at 5 °C, the Cα–Co(carboxylate) bond is oriented obliquely to the surface. When the “Raney nickel” film is modified at 100 °C, the Ni-alanine chelate is formed on the surface: the Cα–Co bond and the NH2 group are nearly parallel to the substrate surface, while the O···O axis is vertical to that surface.
The Adsorption of α- and β-Cyclodextrins on the Dropping Mercury Electrode in an Aqueous Solution
Authors: Matsui Yoshihisa , Sawada Hiroshi , Mochida Kazuo , Date Yoshio
Published: July 2006

The adsorption of α- and β-cyclodextrins on the surface of the dropping mercury electrode was examined in a phosphate buffer solution by means of voltammetry with a triangular potential sweep. The α- and β-cyclodextrins gave two capacitive peaks corresponding to the adsorption and desorption processes respectively. The α-cyclodextrin additionally gave two cathodic peaks and an anodic peak, probably due to reorientation processes. The effects on the peak heights were investigated in terms of the sweep rate, the cyclodextrin concentration, the temperature, the ionic strength, and the pH. The adsorption of both cyclodextrins followed the Langmuir isotherm, and the equilibrium constants for the adsorption were evaluated to be 1.2×104 M−1 for α-cyclodextrin and 1.0×105 M−1 for β-cyclodextrin at 25°C and pH 6.5.
The X-Ray Photoelectron Spectroscopy of o-Hydroxy Aromatic Azo Metal Complexes
Authors: Yoshida Tooru , Sawada Shigemasa
Published: July 2006

The photoelectron spectra of azo metal complexes were measured. There was no significant change in the profile or the binding energy of the N(ls) peak upon coordination. It was deduced that, in the bond between the azo-group and the metal, there is a contribution of a π-bonding.
Chemical Effects of 31P(n,γ)32P Reaction in Phosphate Glass—A Radiation Chemical Approach to Hot Atom Chemistry
Authors: Lin Tsing-Ko , Matsuura Niro
Published: July 2006

Sodium metaphosphate glass, with a polymerization degree of 50–100, was used as target material for the study of the chemical effects of (n, γ) reaction. Mean oxidation number of 32P was introduced as a new parameter to elucidate the oxidation reaction brought on the recoil product. The mean oxidation number of 32P from (n, γ) recoil in such glassy polyphosphate was about +4. More than 90% of the 32P set free was reattached as an end group in the newly formed radioactive polyphosphate. The recoiled monoatomic 32P species (less than 10% of the total 32P) defficient in oxygen kept a low mean oxidation number ca. +3. Ionizing radiation produced color center (with λmax at 510 nm) which seemed partially to oxidize the 32P product. The effect was very weak, and could be suppressed by the hold scavengers. Thermal annealing showed that the mean oxidation number of 32P rapidly attained +5 (the valence of target) by 300 °C; however, it seems very difficult to raise the mean oxidation number of 32P to +5 by γ-ray annealing. The oxidation of 32P through thermal annealing is considered to be a diffusion process, with an activation energy of ca. 7×103 cal/mol. Possible reaction between the hot-zone and the radiation spurs is discussed.
The Mechanism of Amine Sensitization of the Emission of Tris(dibenzoylmethano)europium(III)
Authors: Fukuzawa Tadashi , Ebara Nozomu , Katayama Mikio , Koizumi Hideaki
Published: July 2006

The mechanism of enhancement of emission quantum yield of the methanol solution of tris(dibenzoylmethano) europium (III) by triethylamine has been investigated. Lifetime of Eu3+ resonance emission of the chelate did not change remarkably when triethylamine was added. The aspect of temperature dependence of the emission intensity was similar for both the chelate itself and the chelate-amine adduct under direct excitation of the metal level, but differed under excitation of the ligand. It was suggested that the sensitization is mainly due to a suppression of nonradiative process in the ligand triplet state.
The Additions of Acetic Acid to Limonene over Solid Acid Catalysts
Authors: Yamanaka Tohr
Published: July 2006

The addition of acetic acid (AcOH) to limonene (IV) over 111–333 g/1 of solid acid catalysts, at 28–92 °C and in an excess of AcOH (19–100 times of IV in molarity), were studied in terms of the kinetic data, at a total conversion of IV less than 10 mol%, and in terms of acid strength distributions of the catalysts. In the reaction medium, a leveling of the acid strength on solids was observed. For the formation of α- and β-terpinyl acetates (I and II) and a mixture of the isomeric p-menthadienes (III) as by-products, (1) the rates are proportional to the square root of the initial concentrations of IV; (2) the apparent activation energies are 18.3 kcal/mol for all the catalysts, and (3) the pre-exponential factors are roughly proportional to the square root of the highest acidity (h0,max) of the catalyst surface in the medium. The effects of the acid properties of the catalyst on the catalytic activity and the selectivity are different from those in a homogeneous liquid acid-catalyst system.
A Temperature-Jump Study of Electron-Transfer Reactions Involving Ion Radicals: Reactions of the Cation Radicals of Phenothiazine and Aromatic p-Diamines
Authors: Yamagishi Akihiko
Published: July 2006

The reversible one-electron-transfer reactions of the following cation radicals were studied by temperature-jump and stopped-flow methods: phenothiazine (PhZ)/N,N,N′,N′-tetramethyl-p-phenylenediamine cation (TMPD\underset.+), PhZ/N,N-dimethyl-p-phenylenediamine cation (DMPD\underset.+), DMPD/TMPD\underset.+ and DMPD/N,N,N′,N′-tetramethylbenzidine cation (TMBZ\underset.+). The solvent used was either 1 : 3 ethanol-water or acetonitrile. For PhZ/TMPD\underset.+, PhZ/DMPD\underset.+ in ethanol-water and also for DMPD/TMPD\underset.+ in acetonitrile, the backward reaction corresponding to the negative free energy change of reaction (ΔF°<0) proceeds almost at the diffusion controlled rate. The backward rate constant for DMPD/TMPD\underset.+ in ethanol-water, (6±1)×108 M−1 s−1, is slightly less than a diffusion controlled one even for ΔF°<0. The results are discussed as compared with the previous study on 7,7,8,8-tetracyanoquinodimethane/substituted-p-benzoquinone anions.
Stability Constants of Several Aliphatic Uranyl Carboxylates
Authors: Kim Bong-il , Miyake Chie , Imoto Shosuke
Published: July 2006

The stability constants of uranyl carboxylates were determined spectrophotometrically; for butyrate, they were logK1=2.96, logK2=2.66, logK3=2.43, and logK4=2.23; for isobutyrate, logK1=2.74, logK2=2.20, and logK3=1.66; for valerate, logK1=2.91, and logK2=2.52, and for isovalerate, logK1=2.90 and logK2=1.91.
Solution Properties of Phycocyanin. III. Studies of the Sedimentation Equilibrium of Phycocyanin
Authors: Mizuno Haruo , Saito Takahide , Iso Naomichi
Published: July 2006

The dissociation-association behavior of phycocyanin has been studied by sedimentation-equilibrium measurements under various pH and ionic-strength conditions. The weight-average molecular weight of phycocyanin changed according to the changes in concentration of the solute. From the concentration dependence of the molecular weight, it has been claimed that the dissociation-association equilibrium system of phycocyanin is trimer\ightleftharpoonsmonomer at pH 6.8 in the relatively low concentration region and hexamer\ightleftharpoonsmonomer at pH 5.4. However, the coexistence of the trimer\ightleftharpoonsmonomer and hexamer\ightleftharpoonsmonomer systems is in evidence in the concentration region larger than 0.06 g/dl. This dissociation-association behavior of phycocyanin is supported by the experimental results obtained from sedimentation-transportation and osmotic-pressure measurements.
Long-range Interaction between a Hydrogen Atom and a Hydride Ion
Authors: Yamabe Tokio , Tanaka Kazuyoshi , Ueno Hiroshi , Fukui Kenichi
Published: July 2006

The long-range force between a hydrogen atom and a hydride ion has been studied by means of the second-order perturbation theory. This H–H− system has been chosen as the simplest example of a system composed of a neutral atom and an anion. The results seem to suggest that the analytical closed form of the second-order energy is desirable for any discussion of the long-range interaction between H and H− in place of the usual multipole expansion. According to the multipole expansion until the R−12 term, the nature of the long-range interaction operating in this system seems to be dispersive, and it seems to become inductive at a much larger R because of the existence of the leading R−4 term.
Tantalum Carbide Formed by the Carbonization of Ta2O5 in an Argon Plasma Arc
Authors: Matsumoto Osamu , Saito Michio
Published: July 2006

The formation of tantalum carbide by the carbonization of Ta2O5 with graphite by heating in an argon plasma arc was studied. Chemical and X-ray analyses showed that the product obtained was either stoichiometric or a defect carbide with the formula of TaC1−X. The products were found to be superconductors.
The Formation of the Rhodium Carbonyl Complexes from Chlorotris-[triphenylphosphine]rhodium with Alcohols in the Presence of Diene and Olefin
Authors: Yamada Akira , Fukuda Takashi , Yanagita Masaya
Published: July 2006

The decarbonylation of alcohols using chlorotris[triphenylphosphine]rhodium in the presence of diene or olefin occurs with the formation of the rhodium carbonyl complex and a hydrocarbon originating from the alcohol. The most suitable reaction system is rhodium compound/methanol/butadiene. The results suggest catalysis by a rhodium species.
The Inductive Susceptance Observed with Electrode Reaction of Water at Far Negative Potentials
Authors: Takahashi Katsuo , Matsuda Kiyoshi , Tamamushi Reita
Published: July 2006

The admittance of various electrodes/dilute aqueous electrolyte solution systems was measured at far negative potentials in the frequency range of 22–500 Hz, and the experimental results were discussed in terms of the mechanism of the electrochemical reduction of water molecules. The frequency dependence of the conductance- and susceptance-components was analyzed by assuming possible equivalent circuits. It was concluded that, in the systems which give inductive susceptances at low frequencies, the reduction of water proceeds according to the electrochemical mechanisms;

H_2O+e→H_ad+OH^-, H_ad+H_2O+e→H_2+OH^-

where the current density due to the second reaction path is proportional to the product of θ and (1–θ), θ being the coverage of the electrode surface by adsorbed hydrogen atoms, Had. At some metal electrodes in solutions of alkali-metal cations, no inductive susceptance was observed; this suggests that the hydrogen evolution proceeds according to other mechanisms.
The Syntheses of Several N,N′-Bis(hydroxymethyl)parabanic Acid Derivatives
Authors: Tanimoto Shigeo , Taniyasu Ryozo , Okano Masaya
Published: July 2006

Starting from N,N′-bis(hydroxymethyl)-parabanic acid, the following new compounds have been synthesized: N,N′-bis(aiylaminomethyl)parabanic acids, N,N′-bis(bromomethyl)parabanic acid, and N,N′-bis(alkoxymethyl)parabanic acids.
Multidentate Ligand Kinetics. I. The Ligand Substitution Reaction between Ethylenediaminetetraacetatocuprate(II) and Triethylenetetraminezinc(II)
Authors: Katsuyama Tetsuo , Kumai Toshihiko
Published: July 2006

The kinetics and the mechanism of the ligand substitution reaction between ethylenediaminetetraacetatocuprate-(II)(CuY2−) and triethylenetetraminezinc(II)(ZnT2+) were studied spectrophotometrically in the pH range 7.0–10.5 at I=0.2(NaClO4) and 25.0 °C. The exchange reaction was accelerated by traces of either EDTA or triethylenetetramine(Trien). The exchange reaction was shown to proceed by the chain reaction mechanism where the chain-propagating steps are the reaction of CuY2− with Trien and the reaction of ZnT2+ with EDTA. Each chain-propagating step was investigated. The apparent rate constant of the reaction of CuY2− with Trien increases with pH, while that of ZnT2+ with EDTA decreases with pH.
The Amperometric Titration of Metal(II) Ions with trans-1,2-Cyclohexanediamine-N,N,N′,N′-tetraacetate (CyDTA)
Authors: Kodama Mutsuo
Published: July 2006

The use of CyDTA in the amperometric determination of metal-ion mixtures was studied systematically. Because of the sluggishness of the nickel(II)-EDMA∼CyDTA substitution reaction, the nickel(II) ion in the EDMA solution could be masked completely in respect to the CyDTA. Therefore, even in the presence of an excess of nickel(II)ions, the copper(II), lead(II), cobalt(II), cadmium(II), and zinc(II) ions in the EDMA solution at about pH=6.50 could be determined accurately with CyDTA. In the amperometric titration of binary mixture of copper(II) and zinc(II), lead(II), cadmium(II), or cobalt(II) ions in the EDMA solution, titration curves with two sharp breaks could be obtained by following the change in the diffusion current due to the reduction of the copper(II)–EDMA complex. The first and second breaks correspond, respectively, to the equivalence point of zinc(II), lead(II), cadmium(II), or cobalt(II) and to that of copper(II).
Mixed Complexes with Bulky Ligands. I. Cobalt(II) Complexes Containing N,N-Bis[2-(dimethylamino)ethyl]methylamine
Authors: Utsuno Shunji
Published: July 2006

Nine new cobalt(II) complexes were prepared which contained N,N-bis[2-(dimethylamino)ethyl]methylamine (dienMe) and some unidentate or bidentate ligands, such as acetonitrile, ammonia, ethylenediamine (en), trimethylenediamine (tn), the acetylacetonate ion (acac), or the oxalate ion. The solid-reflectance spectra revealed that six complexes of the [Co(XX)dienMe](ClO4)n formula (XX=2CH3CN, 2NH3, en, tn, acac, or 1/2C2O4; n=1 or 2) are five-coordinated, whereas three complexes, [Co(C2O4)(H2O)dienMe] and Co(C2O4)1⁄2 (solv)(dienMe)ClO4 (solv=CH3CN or CH3OH), are six-coordinated. On the basis of their electronic spectra, most of the five-coordinated complexes were supposed to have a trigonal-bipyramidal structure in the solid state and in solution. The IR spectra of three hemioxalato complexes revealed the presence of quadridentate oxalateion bridging between two cobalt ions, regardless of their coordination number.
The Bromination of 1- and 2-Methylthiophenazine Derivatives
Authors: Tada Masao
Published: July 2006

The bromination of 1-methylthiophenazine has been investigated and found to occur in Position 4. 2-Methylthiophenazine and its 5-oxide have been found to be brominated in Position 1. The bromination of these compounds in acetic acid gave both a ring-substituted product and its oxidised product.
The Retardation of the Benzidine Rearrangement of Hydrazobenzene by Cyclodextrins
Authors: Matsui Yoshihisa , Mochida Kazuo , Fukumoto Osamu , Date Yoshio
Published: July 2006

The benzidine rearrangement of hydrazobenzene is retarded by the addition of α-, β-, and γ-cyclodextrins. The effects on the rate of the cyclodextrins are decreased by the addition of cyclohexanol. The deceleration of the reaction by the cyclodextrins was attributed to the equilibrium complexation of the substrate in the cavities of the cyclodextrins, which may either restrict the large conformational change of the substrate necessary for reaching a sandwich-type transition state or lower the concentration of the diprotonated hydrazobenzene by means of the space alkalinity of cyclodextrins.
Hydrogenation and Hydrogenolysis. XV. Hydrogenation of Isomeric Anisidines with Platinum Metal Catalysts in Acetic Acid
Authors: Nishimura Shigeo , Takaoka Takeaki , Maekawa Yoshihiro
Published: July 2006

m-Anisidine was hydrogenolyzed to an extent of 92.5% in hydrogenation with a palladium catalyst in acetic acid at 60 °C and 90 kg/cm2. The amount of hydrogenolysis in o- and p-anisidine was only 2.1 and 2.5%, respectively. This great difference in hydrogenolysis between the isomers was not observed with rhodium and platinum catalysts. With m- and p-anisidines, selectivity at the initiation of hydrogenation was studied for the formation of N-cyclohexylanisidine intermediates and for other products by an extrapolation method. Extensive hydrogenolysis of m-anisidine and slight hydrogenolysis of o- and p-anisidines over palladium result from a high selectivity in the formation of the enamine or imine intermediates. The hydrogenation pathways leading to hydrogenolysis and secondary amine formation over the three platinum metals are discussed.
Über die Feststellung der Wanderung des Äthoxycarbonyl-Restes bei der Dienon-Phenol-Umlagerung
Authors: Suehiro Tadashi , Yamazaki Shozo
Published: July 2006

3,4-Dimethyl-4-äthoxycarbonyl-cyclohexa-2,5-dienon-4-14C (9) lagert sich bei 60–70 °C in 60% Schwefelsäure zu 2,3-Dimethyl-5-hydroxybenzoesäure-äthylester-2-14C (10, 99.8%) und -1-14C (10b, 0.2%) insgesammt in ca. 50% Ausbeute um, unter Nebenbildung von 3,4-Xylenol (11, 12%) und 2,3-Dimethyl-5-hydroxybenzoesäure (12, 5%). Dass 10 die Struktur von 2,3-Dimethylbenzoesäure-Derivat hat, wurde durch Mischprobe mit der authentischen Verbindung festgestellt.
Photochemical cis-trans Isomerization of 2,4,5-Triphenylimidazolines
Authors: Matsuura Teruo , Ito Yoshikatsu
Published: July 2006

Irradiation of cis- (amarine; I) and trans- (isoamarine; II) 2,4,5-triphenylimidazolines in acetonitrile or benzene gave a photostationary mixture of cis- and trans-isomers, the latter predominating over the former. On irradiation in a dilute acetone solution under the conditions that acetone absorbed most of the incident light, cis-trans isomerization occurred only with isoamarine but not with amarine. In acetone, 2,4,5-triphenylimidazole (III) was also formed. Two kinds of intermediate species for the cis-trans isomerization were proposed; imidazolinyl radicals IV and/or V formed by hydrogen abstraction with the excited state of acetone (in acetone) and a biradical or a zwitterionic species VIa formed by cleavage from the excited state of I or II (in acetonitrile or benzene). Evidences for the intermediacy of VIa are presented.
Solvent Effects under High Pressure. II. Determination and Applications to Kinetic Studies of the ET-Value at High Pressures
Authors: Tamura Katsuhiro , Imoto Tatsuya
Published: July 2006

The ET-value was determined for eight solvents at 25 °C over the pressure range 1–1,960 kg/cm2. They increase with pressure; the pressure dependence is affected by the nature of the solvents. It was also found that there is a linear relationship between the pressure coefficient of ET and that of the logarithm of the rate constant of a Menschutkin reaction: In k=a+bET On the basis of this relationship, an equation was derived in which the volume of activation ΔV\eweq is represented by the pressure coefficient of ET; the effect of solvents on ΔV\eweq is discussed by making use of this equation.
(−)-(1S,4R,5R)-Guaia-6,9-diene from Geranium Bourbon
Authors: Nagahama Yoko , Naoki Hideo , Naya Yoko
Published: July 2006

A sesquiterpene from Geranium Bourbon has been found to be guaia-6,9-diene in accordance with the report of Pesnelle et al.; it had previously been erroneously assigned as 3,7-diene by Herout et al. The details of the evidence on the structure, along with its stereochemistry, are described.
Absolute Configuration of 3-Amino-1-phenylbutane
Authors: Yamamoto Yukio , Oda Jun’ichi , Inouye Yuzo
Published: July 2006

The absolute configuration of (−)-3-amino-1-phenylbutane was established by the correlation to (R)-(−)-N-benzoylalanine methylester via (+)-trans-3-amino-1-phenylbut-1-ene.
Solvent Extraction Equilibria of Thallium(III) from Weakly Acidic Chloride Solutions into 4-Methyl-2-pentanone
Authors: Hasegawa Yuko , Kurihara Shinji , Masui Naohito , Sekine Tatsuya
Published: July 2006

From the distribution data of thallium (III) between 4-methyl-2-pentanone and 4 mol dm−3 sodium per chlorate solutions containing chloride ions at pH 2, the Na+TlCl4− species in the organic phase and the TlCl2+, TlCl3, and TlCl4− species in the aqueous phase were recognized. The equilibrium constants for the formation and extraction of these complexes were determined.
Reaction of N-Aroyl-N-arylhydroxylamines with o-Nitrobenzenesulfenyl Chloride
Authors: Oae Shigeru , Sakurai Tadamitsu
Published: July 2006

Reactions of N-aroyl-N-arylhydroxylamines with o-nitrobenzenesulfenyl chloride were found to afford the corresponding N-aroylarylamines and S-(o-nitrophenyl) o-nitrobenzenethiosulfonate in good yields, respectively. Both the product distributions and the effect of substituents on the amount of reduction product suggest these reactions to proceed via homolytic cleavage of the N–O bond.
Synthesis of (2-Chloroethyl)-nitrosourea Derivatives of Carbohydrate
Authors: Machinami Tomoya , Nishiyama Shigeru , Kikuchi Kazuo , Suami Tetsuo
Published: July 2006

Six antileukemic carbohydrate derivatives which have a (2-chloroethyl)-nitrosoureido group have been prepared by a reaction between amino sugars and 2-chloroethyl isocyanate, followed by nitrosation.
Reaction of a Stable Free Nitrogen-Centered Radical, 3,4-Dihydro-2,4,6-triphenyl-2H-1,2,4,5-tetrazin-1-yl, with Orgranoaluminum Compounds
Authors: Miura Yozo , Morimoto Yuzo , Kinoshita Masayoshi
Published: July 2006

Reactions of 3,4-dihydro-2,4,6-triphenyl-2H-1,2,4,5-tetrazin-1-yl (1) with triethylaluminum, triisobutylaluminum, and diethylaluminum chloride were examined, and from the product analysis, these reactions are proposed to proceed by means of a homolytic substitution process.
The Convenient Syntheses of Biopterin and Its Three Opitical Isomers
Authors: Sugimoto Takashi , Matsuura Sadao
Published: July 2006

Simple syntheses of biopterin (4a) and its three optical isomers (4b, c, d) are described. The condensation of 2,4,5-triaminopyrimidin-6(1H)-one (1) with each of the 5-deoxypentose phenylhydrazones (2a, b, c, d), followed by oxidation with K3[Fe(CN)6] and H2O2 in the presence of KI, gives biopterin (4a) and the isomers (4b, c, d) respectively.
Detection of Hydrophobic Stain on Cotton Surface by Fluorescent Probe
Authors: Seimiya Toshiko , Purchase Mary E
Published: July 2006

The minute amount of hydrophobic substances 10−8∼10−7 mol/cm2 (geometric area) on cotton fabric surface can effectively be detected by fluorescent probe using magnesium-8-anilino-1-naphthalenesulfonate (ANS). The cotton fabrics were dyed in aqueous ANS solution (1×10−4 mol/1), before and after the staining with stearic acid, palmitic acid, tristearin, oleic acid, and squalene, and the intensities of fluorescence from the cotton surface was measured by reflectance spectrophotometer under the varying wavelength of ultra-violet (200–300 mμ). The intensity of fluorescence increased with the increase of fatty stain on the surface, but showed the tendency of saturation by exceeding the closest packing of the fatty acid monolayers. Correlation was also found between the fluorescent intensity and the yellowness (b-value) of naturally soiled cotton fabrics. The bleaching of the yellowed fabrics by sodium hypochlorite effectively reduced the b- value but did not change the fluorescence appreciably, and suggested that the hydrophobic substances still remained on the fabric surfaces in spite of their white appearance.
Use of the Copper(II)-Selective Electrode for the Determination of the Stability Constants of Copper(II) Complexes
Authors: Nakagawa Genkichi , Wada Hiroko , Hayakawa Tomohiko
Published: July 2006

In the determination of stability constants of metal complexes, usually the measurements of the activities of free metal ions at very low levels are required. The electrode response of an Orion Model 94–29 copper(II) ion selective electrode at very low activity levels was studied in the various metal buffers composed of copper(II) ions and an excess of ligand. Usually the linear calibration range of the copper(II) ion selective electrode was extended to very low activity levels in the presence of a strong complexing agent. The stability constants of copper(II) complexes with acetate, ammonia, ethylenediamine, glycine, iminodiacetic acid, 1,10-phenanthroline, etc. were determined successfully. In the cases of EDTA and NTA, however, the lower limit of the linear calibration range was abnormally high and the stability constant of copper–EDTA or –NTA chelate could not be obtained. Some experimental results on the potentiometric titration of copper(II) ion with EDTA were also presented.
The Effect of the Pressure on the Micellization of the Surfactant in Aqueous Urea Solutions
Authors: Tanaka Mitsuru , Kaneshina Shoji , Kuramoto Seiji , Matuura Ryohei
Published: July 2006

The critical micelle concentrations (CMC) of dodecyltrimethylammonium bromide (DTAB) in aqueous urea solutions have been determined over a range of pressures up to 2500 atm at 25 and 35 °C. The partial molal volumes of DTAB in micellar (\barVm) and singly-dispersed states (\barVs) have also been determined in aqueous urea solutions at 25 °C. \barVs increases with the addition of urea, while \barVm remains approximately constant. The partial molal entropy change of micellization (Δ\barSm) in water increases with an increase in the pressure up to about 1500 atm, while Δ\barSm in 3-m urea solution remains virtually unaltered in the low-pressure region. The results suggest that the “iceberg” structure of water around the hydrocarbon chain of the monomeric surfactant is effectively broken down by urea.
The Polarographic Behavior and Determination of Orotic Acid (Vitamin B13) in Milk
Authors: Yao Toshio , Musha S\={o}ichir\={o}
Published: July 2006

The polarographic behavior of orotic acid at the dropping mercury electrode was studied in the Britton-Robinson buffer solution; it was found to be a complex function of the pH. Three polarographic waves were observed over the pH range from 2 to 12. In the 1M HClO4 electrolyte, orotic acid showed a very well-defined, diffusion-controlled, two-electron polarographic reduction wave which enabled us to determine orotic acid polarographically. A polarographic method for the determination of orotic acid in milk was proposed, and the effect of the presence of surface-active substances like proteins was investigated. The proposed method is very simple and rapid, and permits the accurate determination of 4–1000 μg/g of orotic acid in milk.
Magnetic Circular Dichroism of [Cr(CN)5NO]3−
Authors: Kobayashi Hiroshi , Eguchi Ken , Kaizu Youkoh
Published: July 2006

Magnetic circular dichroism (MCD) was observed in the region of the 22000 cm−1 band of [Cr(CN)5NO]3−. The absorption band was assigned to a charge-transfer transition linearly polarized in the direction of Cr–NO, while the MCD observed in the same region was assigned to B term extrema of the (d, d*) transitions hidden beneath the charge-transfer band. The charge-transfer transition gives rise to an absorption peak but no MCD, since the transition is polarized in the direction of the orbital angular momentum, even in the case where a degenerate excited state is involved.
Polarized Reflection and Absorption Spectra of the [2.2]-Paracyclophane Crystal
Authors: Fuke Kiyokazu , Nagakura Saburo
Published: July 2006

The reflection spectra of a [2.2]-paracyclophane crystal were measured in the 17000–62000 cm−1 region with incident light polarized parallel and perpendicular to the a-axis. From analysis of the reflection spectra by the Kramers-Kronig method, the a-axis and c-axis polarized absorption spectra in the 38000–60000 cm−1region were obtained. The c-axis polarized spectrum was obtained for the first time. The 43000 cm−1 band in the c-axis spectrum was assigned to the transitions to the 1B1u(p) and 1B1u (CT) states. The band around 48000 cm−1 was assigned to the transition to the 1B3u-state, corresponding to the transition to the 1E2g -state in benzene.
Magnetic Circular Dichroism of Dicyanobis(2,2′-bipyridine)iron(II)
Authors: Kobayashi Hiroshi , Agarwala Badri Vishal , Kaizu Youkoh
Published: July 2006

Magnetic circular dichroism (MCD) of cis-dicyanobis(2,2′-bipyridine) iron(II) was measured for a variety of solvents. The visible absorption band is assigned to the lowest “iron(II) to bipyridine” charge-transfer transition. The complex exhibits a significant MCD in its lowest charge-transfer absorption band. The transition shows a shift to higher wave number with an increase in the proton-donating power of solvent. This spectral shift is attributed to hydrogen-bonding interactions of protolytic solvent molecules. In H2SO4 this dibasic complex is subjected to stepwise protonations. The complex is diamagnetic in protolytic solvents, and even in cone H2SO4 the diprotonated complex formed is mostly present in the diamagnetic state.
Reaction of Cupric Ion Fixed on the Ion Exchange Resin with Acetylacetone
Authors: Okamura Takashi , Ohzeki Kunio , Kambara Tomihito
Published: July 2006

It was found that the cupric ions fixed on the resin are removed by acetylacetone(Hacac) to form bisacetylacetonatocopper(II), Cu(acac)2. By the addition of a small amount of pyridine-water mixture to the copper-(II) form resin in acetylacetone milieu, the cupric ions are quantitatively removed from the resin in the form of pyridine adduct, and the pyridinium ions are adsorbed on to the resin in place of the cupric ions. The reaction was successfully applied to the synthesis of Cu(acac)2.
Metal Complexes Containing Six-membered Chelate Rings V. Preparation and Structure of Oxalato Complexes of Cobalt(III) with Substituted 3,7-Diaza- 1,9-nonanediamine Derived from 2,4-Pentanediamine
Authors: Mizukami Fujio
Published: July 2006

The syntheses, resolution and structure of three oxalato complexes of cobalt(III) with tetramine ligand, R(4), R(6)- and R(4), S(6)-4,6-dimethyl-1,9-nonanediamine (RR- and RS-2,3″, 2-tet), and R(6), S(8)-6,8-dimethyl-2,5,9,12-tetraazatridecane (N,N′-Me2-RS-2,3″,2-tet) are reported. Only one geometrical isomer (cisβ) was isolated for each complex, [Co(ox)(N,N′-Me2-RS-2,3,″,2-tet)]+, [Co(ox)RS-2,3″,2-tet]+ and [Co(ox)RR-2,3″,2-tet]+· The central six-membered chelate rings of (−)546-cis β-[Co(ox)(N,N′-Me2-RS-2,3″,2-tet]+ and (−)546-cis β-[Co(ox)(RS-2,3″,2-tet)]+ take a chair conformation with two equatorial methyl groups, and that of (−)546-cis β-[Co-(ox)(RR-2,3″,2-tet)]+ a chair conformation with an axial and equatorial methyl group.
Reactions of Sulfenes with Schiff Bases. The Stereochemistry and Thermal Fragmentation of Thiazetidine 1,1-Dioxide
Authors: Hiraoka Tetsuo , Kobayashi Takeo
Published: July 2006

Phenylsulfene (II) generated from benzylsulfonyl chloride (I) and triethylamine, reacted with N-(p-Substituted)-benzylidene-methylamine to give 2-methyl-4-phenyl-3-(p-substituted-phenyl)-1,2-thiazetidine 1,1-dioxide whose cis and trans isomers were separated. Both cis and trans 3,4-diphenyl-2-methyl-1,2-thiazetidine 1,1-dioxide (IV and V) afforded trans stilbene and benzaldehyde on pyrolysis. This new fragmentation reaction could be explained by a stepwise decomposition because of its non-stereospecificity.
Formation of Phosphate Derivatives by the Reaction of Propyl and Allyl Halides with Phosphorus Trichloride and Oxygen
Authors: Okamoto Yoshiki , Okada Toshihiro , Sakurai Hiroshi
Published: July 2006

In addition to phosphonyl dichlorides, a significant amount of phosphoryl dichlorides was obtained by the reaction of propyl and allyl halides with phosphorus trichloride in oxygen atmosphere. Formation of the P–O–C bond can be explained by a scheme involving a preferential reaction of the bridged intermediate radical with oxygen.
The Convenient Synthesis of Anhydronucleosides via the 2′,3′-O-Sulfinate of Pyrimidine Nucleosides as the Active Intermediates
Authors: Sowa Tsuneo , Tsunoda Kozo
Published: July 2006

The synthesis of 2,2′-O-anhydro(1-β-d-arabinofuranosyl) cytosine (3a) and 2,2′-O-anhydro(1-β-d-arabinofuranosyl) uracil (3b) is described. The active intermediates, 2′,3′-O-sulfinyl cytidine (2a) and 2′,3′-O-sulfinyl uridine (2b), were prepared from the corresponding nucleosides (1a or 1b) by successive treatment with thionyl chloride in acetonitrile and with water. The 2,2′-O-anhydropyrimidine nucleosides were formed quantitatively by heating the intermediates in an acidic aqueous solution or in N,N-dimethylformamide in the presence of sodium acetate. The treatment of the anhydronucleosides with alkali gave the corresponding arabinonucleosides.
Studies of Reaction Mechanisms with All-valence Electron Semi-empirical SCF MO Theories. IX. The Role of Tetracyclo[4.2.0.02,805,7]oct-3-ene on the Ground State Potential Energy Hypersurfaces of (CH)8 Isomers
Authors: Iwamura Hiizu , Kihara Hiroshi
Published: July 2006

Tetracyclo[4.2.0.02,805,7]oct-3-ene (1) is estimated by a MINDO MO calculation to be moderately strained. Interaction between the ethylenic π orbital and the Walsh orbitals of the two cyclopropane rings is extensive in the ground state structure of 1. The third highest occupied MO is an out-of-phase combination of the ethylenic 2pπ AO’s on C3 and C4, while the corresponding in-phase combination appears in the lower unoccupied MO’s. The interconversion between 1 and bicyclo[4.2.0]octa-2,4,7-triene (2) is a typical symmetryallowed reaction as revealed by a smooth change in bond indices along the reaction coordinates. The isomerization of substituted cyclooctatetraenes via  1 and 2 (Eq. (2)) is predicted to be possible at elevated temperatures. The symmetry-allowed degenerate valence isomerization of 1 (Eq. (3)) is energetically less favorable due to skeletal constraint.
The Stereochemistry of Autoxidation of 2-Bromo-1-methylcyclohexane
Authors: Miyajima Shingo , Simamura Osamu
Published: July 2006

Autoxidation of cis-2-bromo-1-methylcyclohexane and subsequent reduction of the resulting hydroperoxide with lithium aluminium hydride gave only t-2-bromo-1-methyl-r-1-cyclohexanol to the exclusion of the c-2-bromoisomer. The reactivity ratio of the C–1 hydrogen in cis-2-bromo-1-methylcyclohexane to that in 1, c-3, c-5-trimethylcyclohexane towards abstraction was estimated to be about 4 by competitive oxidation experiments. An explanation for the acceleration of hydrogen abstraction and the stereospecific oxygen attack on the intermediate radical is given in terms of a bromine bridged radical. Autoxidation of a sample of 2-bromo-1-methylcyclohexane, containing about 90% of the trans isomer, took place very slowly as compared with the cis isomer.
Phosphinidenes and Related Intermediates. III. Reactions of Phosphinylidenes and Phosphinothioylidenes with Conjugated Dienes
Authors: Nakayama Shigenobu , Yoshifuji Masaaki , Okazaki Renji , Inamoto Naoki
Published: July 2006

Phenylphosphonic and phenylphosphonothioic dichlorides were dechlorinated with magnesium to generate phenylphosphinylidene and phenylphosphinothioylidene, respectively, in the presence of several 1,3-dienes. Reactions of phenylphosphinothioylidene with 2,3-dimethylbutadiene and 1,3-cyclohexadiene gave Diels-Alder type reaction products, that is, 3,6-dihydro-1,2-thiaphosphorin derivatives (5 and 6) and 6-phenyl-5,6-thiaphosphabicyclo[2.2.2]oct-2-ene 6-sulfide (14), respectively. Reaction of 2,3-diphenylbutadiene with phenylphosphinothioylidene afforded 1,2,4,5-tetraphenyl-1,2,3,6-tetrahydro-1,2-diphosphorin 1,2-disulfide (10), whereas that with phenylphosphinylidene gave 1,3,4-triphenyl-3-phospholene 1-oxide (12). The differences of these reactions have been discussed.
The Photolysis of 3,4-Bis(hydroxydiphenylmethyl)cyclobut-3-ene-1,2-dione and Related Compounds. The Formation of a New Bislactone, 4,4,8,8-Tetraphenyl-3,7-dioxabicyclo[3.3.0]oct-1(5)-ene-2,6-dione
Authors: Toda Fumio , Todo Eishiro
Published: July 2006

The photolysis of 3,4-bis(hydroxydiphenylmethyl)cyclobut-3-ene-1,2-dione (1) in benzene afforded 4,4,8,8-tetraphenyl-3,7-dioxabicyclo[3.3.0]octane-2,6-dione (3) in an 80% yield. The photolysis of 1 in MeOH afforded 4,4,8,8-tetraphenyl-3,7-dioxabicyclo[3.3.0]oct-1(5)-ene-2,6-dione (4), 4-methoxycarbonyl-3,3-diphenyl-5-diphenylmethylene-2-oxacyclopentan-1-one (5), and 4-carboxy-3,3-diphenyl-5-diphenylmethyl-2-oxacyclopent-4-en-1-one (6), in 3, 8, and 22% yields respectively. The mechanisms of the formation of the 5 and 6 are discussed. The photolysis of 3-hydroxydiphenylmethyl-4-diphenylmethoxymethylcyclobut-3-ene-1,2-dione (14) and 3,4-bis(diphenylmethyl)cyclobut-3-ene-1,2-dione (18) was also investigated.
The Reactions of β-Amino α,β-Unsaturated Esters with Amines. II. Syntheses of Some New Derivatives of Quinazolines
Authors: Yokoyama Yasukazu , Shibata Katsuya , Fujii Osamu , Iwamoto Eiji
Published: July 2006

The reaction of 1,4-bis(ethoxycarbonyl)-2,5-diamino-1,4-cyclohexadiene(Ia) with aniline in aprotic solvents gave N,N′-diphenylurea, whereas in the presence of a proton acid this reaction gave an amine-exchanged product,14-bis(ethoxycarbonyl)-2,5-dianilino-1,4-cyclohexadiene(Ib). However, when 2-aminopyridine was used in place of aniline for this reaction, 1,4-bis(ethoxycarbonyl)-2,5-bis(2-pyridylamino)-1,4-cyclohexadiene(Ic) was not isolated but its cyclyzed analogue, 6,7,14,15-tetrahydropyrido[2,1-b]pyrido[1′,2′:1,2]pyrimido[4,5-g]quinazoline-7,15-dione(IIa), was obtained. The reaction of 2-amino-6-methylpyridine with la also gave a quinazoline derivative without producing a 1,8-naphthyridine derivative. Since this reaction took place easily in a weak acid, AcOH, this cyclization could proceed by an intramolecular proton-transfer mechanism.
The Extraction of Alkali Metal Picrates with Dibenzo-18-Crown-6
Authors: Sadakane Akira , Iwachido Tadashi , Tôei Kyoji
Published: July 2006

The distribution of alkali metal picrate complexes of macrocyclic polyether (dibenzo-18-crown-6) between water and benzene was investigated. The polyether-cation complexes were found to be of a 1:1 stoichiometry. The formation of 2:1 complexes was recognized for Rb and Cs in a large excess of the poiyether. The extractability of complex cation-picrate ion-pairs decreases in this sequence: K>Rb>Cs>Na>Li. The values of the extraction constants (logKex) were determined to be 4.65, 3.75, and 3.07 for K, Rb, and Cs compounds respectively. The thermodynamic quantities for the extraction process were calculated from the change in the extraction constants with the temperature. The extraction reactions are all exothermic, accompanied by an entropy decrease.
A New Synthesis of 3,6-Dialkyl-1,4-dimethyl-3,6-epithio-and -3,6-epidithio-2,5-piperazinediones
Authors: Yoshimura Juji , Nakamura Hiroshi , Matsunari Kenji
Published: July 2006

A new route for synthesis of 3,6-dialkyl-1,4-dimethyl-3,6-epithio- (8) and -3,6-epidithio-2,5-piperazinediones (9) via the corresponding bromo derivatives was described. Bromination of 3,6-dialkyl-1,4-dimethyl-2,5-piper-azinedione with N-bromosuccinimide gave 3,3α,6,6α-tetrabromo (2) and 3,6-dibromo (3) derivatives, depending upon the straight chain (methyl, ethyl, propyl, butyl) or α-branched (isopropyl, sec-butyl) alkyl groups, respectively. After tentative substitution of 3,6-bromine atoms of 2 with methanol, 3α,6α-bromine atoms were reduced to give the corresponding 3,6-dialkyl-3,6-dimethoxy derivatives (5). Substitution of 3 or 5 with hydrogen sulfide in the absence or presence of zinc chloride, and successive oxidation with potassium triiodide gave 8 and 9 at the same time. Discussions were made on the structure of isomers and on the reaction mechanisms.
Aminosugars. XXIII. l-Idofuranose Derivatives Containing a Heterocycle at C-5,6 Position
Authors: Iwakawa Masaharu , Yoshimura Juji
Published: July 2006

2-Aryl-(5S)- and -(4S)-(3′-O-benzyl- and 3′-O-methyl-1′,2′-O-isopropylklene-α-d-xylo-tetrofuranos-4′-yl)-2-oxazolines (3 and 7) were prepared from 6-aroylamido-6-deoxy-5-O-tosyl-d-glucofuranose and 5,6-aroylepimino-5,6-dideoxy-l-idofuranose derivatives, respectively. The corresponding 2-thioxo-(4R)- and -(5S)-thiazolidine derivatives (11 and 13) were also synthesized from 5,6-dideoxy-5,6-epimino-l-idofuranose and 6-azido-6-deoxy 5-O-tosyl-d-glucofuranose derivatives, respectively. 2-S-Methylated derivatives of 11 and 13 were reduced with aluminum amalgam to give the corresponding (4R)- and (5S)-thiazolidine derivatives, respectively. Formation of an intramolecular hemiaminal ring in 11 gave a new type of bicyclic derivatives; (5S,6R,8R)-triacetoxy-(7S)-substituted-2-thioxo-(8aR)-perhydropyrido[1,2-c]thiazole (16a and 16b). The structure of new compounds was examined by NMR spectroscopy.
The Mass-transfer Rate through the Liquid-Liquid Interface. V. Diffusion through an Interface Considering the Variation in the Amount of Adsorption
Authors: Shimbashi Teruya
Published: July 2006

The diffusion through an interface has been re-formulated considering the variation in the amount of adsorption on the interface in the case of linear diffusion in a finite composite medium.
ESR Spectra of Monoprotonated Semiquinone Radicals Formed during Photolysis of p-Benzoquinone and Its Methyl Derivatives
Authors: Warashina Tetsuo , Edlund Ove , Yoshida Hiroshi
Published: July 2006

Proton hyperfine coupling constants of monoprotonated p-benzosemiquinone, durosemiquinone, 2,6-dimethyl-p-benzosemiquinone, 2,5-dimethyl-p-benzosemiquinone and methyl-p-benzosemiquinone radicals were determined from ESR spectra during photolysis of the corresponding quinones under identical conditions, i.e., in ethanol and at about 20 °C. By considering all these constants together, the ESR spectra were assigned and following results obtained: (1) the hydroxyl groups were at the oxygen atom further from the methyl substituents, (2) the coupling constant was generally −1.86–−1.65 G for the hydroxylic protons, (3) the absolute value of the coupling constant for both ring and methyl protons was in the range 0–0.7 G for ortho-positions and 4.3–5.2 G for meta-positions relative to the hydroxyl group, and (4) the hydroxylic proton of durosemiquinone had an exceptionally small coupling constant because of steric hindrance of the methyl groups. The temperature dependence of the coupling constants in p-benzosemiquinone revealed an asymmetry of the meta-ring protons at low temperature due to the hindrance of hydroxyl group rotation. The coupling constants for p-benzosemi-quinone were calculated with the INDO method. However, the results were not satisfactory because the calculated coupling constant was too large for the ortho-protons and the asymmetry calculated for the conformation with the hydroxylic proton fixed at one of the stationary sites was too small to interpret the observations.
Binuclear Metal Complexes. X. Preparation and Magnetism of Mononuclear and Binuclear Copper(II) Complexes of Schiff Bases Derived from 4,6-Diacetylresorcine and Polyamines
Authors: Manada Noriaki , Okawa Hisashi , Kida Sigeo
Published: July 2006

New binuclear complexes Cu2X2dar(en-R)2 and [Cu2dar(dien)2](ClO4)2·H2O were synthesized, H2dar(A)2being a Schiff base prepared from 4,6-diacetylresorcinol and an amine A;A stands for N,N-dialkylethylenediamine-(=en-R, R=C2H5 or iso-C3H7) or diethylenetriamine(=dien). Mononuclear complexes CuXHdar(en-R) were also prepared for comparison. Two copper(II) ions of the binuclear complexes are separated from each other by the benzene ring. Magnetic susceptibilities of the compounds were measured in the temperature range 77.4∼300 K. It was found by means of the plots of χA−1  versus  T that all the compounds obey the Curie-Weiss law. The Weiss constants for the binuclear complexes (−10∼−34 K) indicate the presence of antiferromagnetic interactions between copper(II) ions through the conjugated π-system of 4,6-diacetylresorcinol moiety, whereas those of the mononuclear complexes are practically zero, showing that the intermolecular interaction is negligibly small.
Physico-chemical Properties of Selenium-Tellurium-Sulfur Crystals
Authors: Nakagawa Toshio
Published: July 2006

The temperature dependence of electric conductivity and Vickers hardness of Selenium–Tellurium–Sulfur (Se–Te–S) crystals were studied. The conductivity decreased with an increase in sulfur content, remaining almost constant when the sulfur content was 40–80 atomic % at 20 and 30 atomic % of tellurium content. When tellurium content was 10%, both conductivity and hardness decreased abruptly when sulfur content exceeded 10%. It was found by means of X-ray diffraction that a hexagonal crystal structure with size twice the lattice constant of Se–Te crystals is formed when the sulfur content is 20% at 10% of tellurium content. When sulfur content exceeds 80%, the crystal structure becomes similar to that of pure sulfur (orthorhombic) at 20 and 30% of tellurium.
Emission Spectra of Dimethoxybenzenes by Controlled Electron Impact
Authors: Ogawa Teiichiro , Imasaka Totaro , Toyoda Minoru , Tsuji Masaharu , Ishibashi Nobuhiko
Published: July 2006

The emission spectra of o-, m-, and p-dimethoxybenzenes under controlled electron impact excitation (200 eV) were measured in the 220–450 nm region at very low pressures. The photoemissions of the excited parent species and such fragment species as H, CH, CO, and CO+ were observed and assigned. The relative intensities of the photoemissions of the parent species were compared with those of the fluorescence spectra (photoexcitation) in an n-hexane solution. The excited parent species, H, and CH were concluded to be produced in one-electron processes; however, the CO+ species were assumed to be produced in both one- and two-electron processes, and the relative contributions are evaluated. It was concluded that the rate of the predissocation of o-dimethoxybenzene was faster than those of the other two isomers, and the observed characteristics of o-dimethoxybenzene had something to do with this faster rate.
Ultrasonic Absorption Mechanism in an Aqueous Solution of n-Propyl Alcohol
Authors: Nishikawa Sadakatsu , Mashima Mitsuo , Yasunaga Tatsuya
Published: July 2006

Ultrasonic absorption in aqueous solutions of n-propyl alcohol was measured in the frequency range of 4.5–220 MHz and in the concentration range of 2.0–13.4 M at 25 °C. Two different relaxation processes were observed; they were attributed to the perturbation of the equilibria expressed by (Remark: Graphics omitted.) where A and B are a single water molecule and an alcohol molecule respectively. The forward and backward rate constants for the two processes were determined from the concentration dependences of the relaxation frequencies. Furthermore, the influence of n-propyl alcohol on the water structure was discussed; the addition of n-propyl alcohol to liquid water was concluded to promote the water structure.
14N Nuclear Quadrupole Resonances of Sulfuric Diamide and Its Derivatives
Authors: Negita Hisao , Kubo Tsuneo , Shibata Kaoru
Published: July 2006

The study of 14N nuclear quadrupole resonance (NQR) was performed on sulfuric diamide (sulfamide) and its methyl derivatives, such as N,N-dimethylsulfamide and tetramethylsulfamide. The 14N NQR parameters for sulfuric diamide and tetramethylsulfamide were (|e2Qq|=3905.3 kHz; η=0.5082) and (|e2Qq|=5325.9 kHz; η=0.1768) respectively. In the case of N,N-dimethylsulfamide, the parameters were (|e2Qq|=4022.9 kHz; η=0.4799) for the nitrogen atoms of NH2 groups and (|e2Qq|=5125.0 kHz; η=0.2024) for the nitrogen atoms of N(CH3)2 groups. From the temperature dependence of the resonance lines due to nitrogen atoms in sulfuric diamide, tetramethylsulfamide, and the NH2 group of N,N-dimethylsulfamide, it is considered that the hydrogen bonds in sulfuric diamide are stronger than those in N,N-dimethylsulfamide. On the other hand, the electron densities for the N–S bond in sulfuric diamide and its methyl derivatives were derived from the corresponding NQR parameters.