bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixed Chelates of Cadmium(II) with N-(2-Hydroxyethyl)ethylenediamine and Some Amino Acids
Authors: Chandel Chandra Pal Singh , Gupta Chand Mal 
Published: July 2006

Abstract
An extended method of Schaap and McMasters has been applied for the study of mixed-ligand complexes of Cadmium(II) with N-(2-hydroxyethyl) ethylenediamine (heda) and some amino acids polarographically at DME. The reduction of mixed-ligand complex at DME has been found to be reversible, and diffusion controlled at temp (30±0.5)°C and μ=1.0 M(KNO3). The formation of MXY, MXY2, and MX2Y has been used to discuss the non-existence of MX3 complexes, where X has been used for heda and Y for amino acids. The values of stability constants β01, β02, β03, β11, β12, and β21 are 3.90, 6.80, 8.94, 8.85, 11.00, and 12.13 for Cd–heda–isoleucinate system, 4.30, 7.70, 9.80, 9.36, 11.75, and 12.42 for Cd–heda–glycinate system, 3.95, 6.81, 8.90, 8.35, 10.99, and 12.12 for Cd–heda–valinate system, 4.10, 7.10, 9.08, 9.02, 11.20, and 12.18 for Cd–heda–serinate system, 4.48, 8.02, 10.33, 9.55, 12.00, and 12.59 for Cd–heda–glutamate system, 4.24, 7.54, 9.54, 9.26, 11.62, and 12.33 for Cd–heda–alaninate system and 4.06, 7.06, 9.02, 9.00, 11.16, and 12.20 for Cd–heda–threoninate system respectively.
Study of the Polymerization of Silicic Acid Adsorbed on Iron(III) Hydroxide by Trimethylsilylation-Gas Chromatography
Authors: Yokoyama Takushi , Shimono Tsugio , Tarutani Toshikazu 
Published: July 2006

Abstract
Polymerization of silicic acid adsorbed on iron (III) hydroxide from dilute monosilicic acid solutions in the concentration range 5–40ppm (SiO2) was studied over the pH range 6–12. Silicic acid species formed on the hydroxide were trimethylsilylated and trimethylsilyl derivatives were detected by gas chromatography. Monosilicic acid adsorbed polymerized, and dimer (Si2O76−), linear trimer (Si2O108−) and tetramer (Si4O1310−), and cyclic tetramer (Si4O128−) were found as polymeric species.
Preparation of Tetraalkyl 2,2′-Phthaloylbis[1,2-dihydro-1-isoquinolylphosphonate]s and their Reactions with Base
Authors: Akiba Kin-ya , Negishi Yoshio , Inamoto Naoki 
Published: July 2006

Abstract
The titled compounds were prepared and the reaction with lithium diisopropylamide followed by quenching with alcohol gave isoquinoline, 13-alkoxy-8H-dibenzo[a,g]quinolizin-8-ones, and dialkyl 2-(o-alkoxycarbonylbenzoyl)-1,2-dihydro-1-isoquinolylphosphonates.
The Crystal and Molecular Structure of Quadrivalent Osmium Porphyrin; μ-Oxo-bis[methoxo(octaethylporphinato)osmium(IV)]
Authors: Masuda Hideki , Taga Tooru , Osaki Kenji , Sugimoto Hiroshi , Mori Masayasu 
Published: July 2006

Abstract
The crystal structure of the title complex has been determined by the X-ray method. The complex crystallizes in the monoclinic space group P2/c with a=24.171(9), b=14.037(3), c=24.401(9) Å, β=119.68(9)°, and Z=4. The structure was solved by the heavy-atom method and refined to R=0.094 for 3838 reflections. Two independent dimers exist with a crystallographically imposed two-fold axis in the unit cell. The two dimers are in an approximately orthogonal arrangement, and they take very similar conformations. The noticeable structural parameters are the average distances of 2.033(28) Å for OsIV–N, 1.808(3) Å for OsIV–O2−, and 1.997(29) Å for OsIV–OCH3. The two porphinato cores bridged by a μ-oxo oxygen atom rotate around the approximately linear Os–O–Os bond (the average valence angle=178°) by 23(1)° from the eclipsed form. The porphine ring is planar within 0.10 Å, and deviation of the Os atom from the porphinato plane of the four nitrogen atoms is 0.06 Å. These results were compared, in the relation of the specific physicochemical properties in solution, with those of the corresponding RuIV complexes reported previously.
Liquid Crystal Formation in Binary Systems. X. Potentially Smectogenic Behavior of Some p-Disubstituted Benzenes
Authors: Chino Eiji , Matsunaga Yoshio , Suzuki Mika 
Published: July 2006

Abstract
Studies on binary systems with nematogenic N-(4-propoxybenzylidene)-4-hexylaniline revealed that 4-nitrophenyl alkanoates, alkyl 4-nitrobenzoates, N-(4-nitrophenyl)alkanamides, and N-alkyl-4-nitrobenzamides are potentially smectogenic. When the Schiff base is mixed separately with a homologous member from 4-nitrophenyl decanoate to tetradecanoate, a stable smectic A phase is induced and its maximum temperature is about 48 °C. The estimated latent transition points to this mesophase of these benzene derivatives are in the range from −25 to 10 °C. On the other hand, only metastable smectic A phases can be produced with hexyl to dodecyl 4-nitrobenzoates, the maximum temperatures being from 15 to 26 °C. While the metastable smectic B phase of the Schiff base is to some extent stabilized by the addition of the alkanoates, it is drastically depressed by the benzoates. The addition of N-(4-nitrophenyl)nonanamide to -dodecanamide produces a stable smectic A phase and also stabilizes the metastable smectic B phase. No smectic A phase is found in mixtures of the Schiff base with N-octyl- to N-dodecyl-4-nitrobenzamides, and the isotropic or nematic-smectic B transition point curves are almost horizontal indicating that these benzene derivatives have transitions to latent smectic B phases between 10 and 20 °C. Results obtained with some related compounds are also presented.
The Micellar Properties of 1-Dodecylpyridinium Chloride as Studied by the Ion-selective Electrodes
Authors: Maeda Tamaki , Satake Iwao 
Published: July 2006

Abstract
The surfactant ion and counterion activities of aqueous 1-dodecylpyridinium chloride with and without KCl were determined by using ion-selective electrodes. In the concentration range above the critical micelle concentration (cmc), the surfactant ion activity (a+) was found to decrease gradually with increasing surfactant concentrations, while the reverse change was found for the counterion activity (a−). As a result, the mean activity increased slightly but regularly with increasing concentrations. The concentration dependences of a+ and a− became progressively smaller as the salt concentration increased. An application of the charged phase separation model led to an apparent degree of counterion association to the micelle (β) of 0.70 regardless of the salt concentration. On the basis of these observations, the estimations were made for the concentration of monomeric surfactant ion (C+) and the activity coefficients of counterion (γ−) and surfactant ion (γ+) above the cmc. The values of C+ and γ+ decreased appreciably, while that of γ− increased with increasing concentrations. The value of β was also estimated from the concentration dependence of a− and the validity of this method was discussed.
The Thermal Properties of Liquid Crystalline Materials Incorporating Cyanothiophene and Cyanofuran
Authors: Miyake Shiro , Kusabayashi Shigekazu , Takenaka Shunsuke 
Published: July 2006

Abstract
Some homologous series of cyanothiophene and cyanofuran compounds have been prepared. 4-Alkoxyphenyl 3-(5-bromo-2-thienyl)acrylate (1) and 4-alkoxyphenyl 3-(5-cyano-2-thienyl)acrylate (2), and 4-alkoxy-phenyl 4-(5-bromo-2-furylcarbonyloxy)benzoate (3) and 4-alkoxyphenyl 4-(5-cyano-2-furylcarbonyloxy)benzoate (4) give rise to a nematic phase. For compound 4, a smectic A phase which commences from the hexyloxy homolog has a bilayer (SA2) arrangement of the molecules. The thermal stabilities of the mesophases are lower than those of the corresponding benzonitrile compounds. This arises from an increased molecular breadth around the terminal portion and the change of the dipole moment arising from the terminal cyano group bending with respect to the long molecular axis.
The Transformation of γ-FeO(OH) to Fe3O4 and Green Rust II in an Aqueous Solution
Authors: Tamaura Yutaka , Saturno Mervelina , Yamada Kaoru , Katsura Takashi 
Published: July 2006

Abstract
A mechanism of the transformation of γ-FeO(OH) to Fe3O4 and/or green rust II in an aqueous solution containing FeII ion in the presence or absence of the SO42− ion at 298 K is described. γ-FeO(OH) is dissolved by two mols of FeII ions adsorbed on the surface of γ-FeO(OH), and a dissolved species (DS) is formed, which is then transformed to Fe3O4 or green rust II. The equilibrium of the formation of green rust II from γ-FeO(OH) is represented by:
K=[H+]2⁄(Kh2[Fe2+]2[SO42−]) K=2.14×108,
where Kh is the hydrolysis constant of Fe2+. This equation shows that, for a given proton concentration(pH), higher concentrations of Fe2+ and SO42− ions facilitate the formation of green rust II from γ-FeO(OH). When little green rust II is formed, the DS is transformed to Fe3O4.
Structure Determination of Bitter Principles of Ailanthus altissima. Structures of Shinjulactones B, D, and E
Authors: Furuno Tetsuo , Ishibashi Masami , Naora Hirokazu , Murae Tatsushi , Hirota Hiroshi , Tsuyuki Takahiko , Takahashi Takeyoshi , Itai Akiko , Iitaka Yoichi 
Published: July 2006

Abstract
Bitter quassinoids, shinjulactones B, D, and E were isolated from Ailanthus altissima Swingle. Shinjulactone B is the first example of natural bitter principles with a 1,2-seco-1-nor-6(5→10)abeo-picrasane skeleton and shinjulactones D and E are a hexahydro derivative and a 6α-hydroxy derivative of ailanthone, respectively.
Hydrolysis of N-Salicylidene-2-methoxyethylamine. Intramolecular General Base Catalysis and Specific Effects of Boric Acid
Authors: Nagamatsu Hiroaki , Okuyama Tadashi , Fueno Takayuki 
Published: July 2006

Abstract
Hydrolysis of N-salicylidene-2-methoxyethylamine is kinetically investigated at 30 °C. Intramolecular general base catalysis by the o-O− substituent takes place in the neutral pH region. Nucleophilic catalysis by morpholine was also found to be operative. Added boric acid accelerates the hydrolysis above pH 5.5 while it decelerates the hydrolysis below pH 5.5. The hydrolysis rate as the function of the boric acid concentration follows a saturation curve in harmony with a reaction sequence involving a rapid equilibrium formation of a borate-substrate complex followed by its breakdown. The morpholine catalysis is inhibited by boric acid in accord with the slow reaction of morpholine with the complex. The water reaction of the complex is considered to involve a rearrangement of the complex and an intramolecular transfer of the boron-coordinated hydroxide ion to the iminium carbon.
Effects of Boric Acid on the Rate and Equilibrium of Schiff Base Formation from Salicylaldehyde
Authors: Nagamatsu Hiroaki , Okuyama Tadashi , Fueno Takayuki 
Published: July 2006

Abstract
Effects of boric acid on the formation of the Schiff base from salicylaldehyde and 2-methoxyethylamine (or glycinate) were examined in aqueous solution. From the formation constants in the absence and presence of boric acid, the equilibrium constants for the borate-Schiff base complexation were determined. The structure of the complex was deduced from the UV spectral analysis. Formation of the Schiff base was found to be accelerated by boric acid (pH 7–10). A mechanism for the reaction involving the complex is presented.
Oxidative Carbonylation of Piperidine in the Presence of Palladium(II)–Copper(II) Catalytic System
Authors: Sheludyakov Yuri L , Golodov Valentin A 
Published: July 2006

Abstract
A kinetic study on oxidative carbonylation of piperidine to give 1,1′-carbonyldipiperidine in the presence of Pd(II) and Cu(II) complexes at 40 °C has been investigated.
On the Physicomagnetic Properties of Some Nitro Compounds
Authors: Abdel-Kader Mohamed M , Salem Safia M 
Published: July 2006

Abstract
The mean molar susceptibilities of nine aromatic nitro compounds namely, o-, m-, p-dinitrobenzene; o-, m-, p-nitrobenzoic acid and o-, m-, p-nitrophenol have been measured. The semiexperimental anisotropies of these molecules have been calculated. The magnetic data are correlated with the positional isomerism of the nitro groups and the crystal structures of these molecules as well as their hydrogen bonding.
Vibrational Spectra and Thermodynamic Functions of 2-Methoxypyridine and 2-Methoxy-d3-pyridine
Authors: Medhi Kanak C 
Published: July 2006

Abstract
The infrared spectra in the liquid state (4000–50 cm−1) and in the vapor phase (4000–400 cm−1) and the polarized laser Raman spectra in the liquid state have been measured for 2-methoxypyridine and 2-methoxy-d3-pyridine. Essentially complete assignments of the observed frequencies are presented. Ideal gas state thermodynamic functions of the molecules are also calculated in the temperature range 200–1500 K.
Aryliminodimagnesium Reagents. VII. The Moderate Electron-donating Ability Estimated by Oxidation Peak Potentials
Authors: Okubo Masao , Tsutsumi Toshiki , Ichimura Akio , Kitagawa Toyokichi 
Published: July 2006

Abstract
Oxidation peak potentials of p-RC6H4N(MgBr)2 and p-RC6H4MgBr (R=CH3O, CH3, F) were determined by cyclic voltammetry with a platinum disk electrode in tetrahydrofuran. The potentials obtained proved to be a semiquantitative measure of electron-donating abilities of organomagnesium reagents.
A Convenient Procedure for Iodination of Electron-rich Aromatic Compounds using Iodine–Copper(II) Acetate
Authors: Horiuchi C Akira , Satoh J Yasuo 
Published: July 2006

Abstract
The iodination of some electron-rich aromatic compounds, namely, three polymethylbenzenes, aniline, phenol, anisole, and phenetole, using iodine–copper(II) acetate in acetic acid, afforded the corresponding iodo compound in high yield.
The Bridging Tridentate-type Carboxylato Ligand in Isomorphous Guanidinium Di(μ-acetato)bis(triacetatoaqualanthanoidates(III)), [(NH2)3C]2-[M2(CH3CO2)8(H2O)2], (M=La, Ce, Pr, Nd, and Sm)
Authors: Sawase Hiroshi , Koizumi Yukio , Suzuki Yasuo , Shimoi Mamoru , Ouchi Akira 
Published: July 2006

Abstract
The M–O bond lengths and some bond angles of the acetato ligands in the title compounds were compared with each other using their structural data as obtained by the single-crystal X-ray diffraction method. With the increase in the atomic number of the central metal atom, the length of the weakest M–O bond in the bridge increases, even though all the other M–O bonds are shortened. This fact can be explained as follows: as the number of ligating oxygen atoms around the central metal atom is almost at a maximum in these complexes, the sharing space of the tenth coordinating atom on the coordination sphere decreases when the radius of the central metal atom is shortened as a result of the lanthanoid contraction effect.
Photoresponsive Crown Ethers. 13. Synthesis of Photoresponsive NS2O Crown Ethers and Application of the Cu(I) Complexes to O2-Binding
Authors: Shinkai Seiji , Shigematsu Kazuyoshi , Honda Yoshihiro , Manabe Osamu 
Published: July 2006

Abstract
Photoresponsive crown ethers with heavy metal affinity were synthesized: They are the NS2O crowns bound to photofunctional azobenzene at 4,4′-positions via X(CH2 or CO) (1(X=CH2) and 1(X CO), respectively). They efficiently extracted heavy metal ions from aqueous phase to organic(dichloromethane) phase. The continuous variation method established that both trans-1 and photoisomerized cis-1 bind two Cu(II) ions forming 1:1 metal/NS2O crown complexes. The trans-1(X=CH2)·Cu(I)2 complex was irreversibly oxidized by O2 to the Cu(II)2 complex, whereas the cis-1(X=CH2)·Cu(I)2 complex bound O2 in a partly reversible manner like Osborn’s complex. Thus, a photoinduced change in the Cu(I)·····Cu(I) interatomic distance is responsible for the stability of the O2 complex. These results show that the extraction of heavy metal ions and the O2-complexation can be controlled by light with the mediation of photoresponsive NS2O crown ethers.
The Magnetic Properties of Cu(CH3COO)2·2NH4Cl and NH4Cu(HCOO)Cl2
Authors: Emori Shuji , Muto Yoneichiro 
Published: July 2006

Abstract
The temperature dependence of the magnetic susceptibility of Cu(CH3COO)2·2NH4Cl obeys the Bleaney-Bowers equation, indicating the existence of the anionic copper(II) acetate dinuclear unit. The exchange integral, J/k, is equal to −205 K. For NH4Cu(HCOO)Cl2, the structure containing copper(II) formate layers connected by tetrachlorocuprate(II) bridges is presumed on the basis of the value of the Weiss constant.
The Radiopolarography of Gadolinium, Ytterbium, and Californium
Authors: Shiokawa Yoshinobu , Suzuki Shin 
Published: July 2006

Abstract
The polarographic reduction of Gd, Yb, and Cf was investigated. It was found that the M(III)→Hg(M) reduction process in an aqueous solution, that cannot be detected by dc polarography, can be detected by radiopolarography. The polarographic behavior of Gd, Eu, Yb, and Cf in the presence of 1,4,7,10,13,16-hexaoxacyclooctadecane(18-crown-6) suggests that Cf(III) is reduced in two steps to Hg(Cf) in an aqueous solution.
Phenanthraquinone Monothiosemicarbazone as Sensitive Reagent for the Spectrophotometric Determination of Zinc(II)
Authors: Sinha Prem Prakash , Sindhwani Sharwan Kumar , Singh Rajendra Pal 
Published: July 2006

Abstract
Phenanthraquinone monothiosemicarbazone has been found to be a sensitive and selective reagent for the spectrophotometric determination of zinc(II) in the pH range 7.0–8.6. The red complex formed shows maximal absorbance at 510 nm. Beer’s law is obeyed up to 1.96 ppm and optimum range of concentration being 0.22–1.70 ppm. The sandell sensitivity is 0.0018 μg ZnII cm−2, with molar extinction coefficient being 3.52×104 mol−1 cm−1. The method has been applied to the determination of zinc in 6% Zn-Al alloy.
The Cooperative Binding Isotherms of Sodium Alkanesulfonates to Poly(1-methyl-4-vinylpyridinium chloride)
Authors: Satake Iwao , Hayakawa Katumitu , Komaki Mayumi , Maeda Tamaki 
Published: July 2006

Abstract
Binding isotherms of nonane-, decane-, and undecane- sulfonate ions to poly (1-methyl-4-vinylpyridinium chloride) were determined by using nitrobenzene-membrane electrode. It was shown that an increase in alkyl chain length is accompanied not only by a rapid increase in the cooperativity parameter but by a regular decrease in an equilibrium surfactant concentration at half binding.
A Modification of the Method of Spectrophotometric Determination of Iron with Ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid)
Authors: Katsuyama Tetsuo , Watanabe Kyoko 
Published: July 2006

Abstract
Etylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (H4eddha) reacts with iron to form a 1:1 complex having an absorption maximum at 480 nm. The method of the spectrophotometric determination of iron with eddha was modified by heating the colored solution in a boiling water bath for a few minutes. The molar absorption coefficient of the FemIII-eddha complex formed was 4.72×103 1 mol−1 cm−1 and the relative standard deviation for determination of 5.90×10−5 mol dm−3 (3.29 μg cm−3) of iron was 0.21%. The effect of 45 diverse ions was examined; only a few metal ions interfered. Aluminium alloys were analyzed for iron by the present method.
Synthesis and Reactions of 1-(Trimethylsilyl)allyl Chloride
Authors: Shimizu Nobujiro , Shibata Fumihiro , Tsuno Yuho 
Published: July 2006

Abstract
1-(Trimethylsilyl)allyl chloride prepared conveniently from 1,3-dichloropropene reacted smoothly with organocopper compounds yielding terminal alkenylsilanes, while its Grignard reactions with carbonyl compounds gave the corresponding alcohols with the regioselection depending sensitively on substrates.
Electronic Spectra of Cyclotrisilane (Si3) and Disilene (Si=Si) Frameworks
Authors: Watanabe Hamao , Kougo Yuichi , Kato Motohiko , Kuwabara Haruyoshi , Okawa Tadashi , Nagai Yoichiro 
Published: July 2006

Abstract
Photolyses of a series of octaalkylcyclotetrasilanes (1) in a hydrocarbon solvent successively afforded hexaalkylcyclotrisilanes (2) and tetraalkyldisilenes (3). Compounds 2 and 3 were found to exhibit their absorption bands corresponding to the lowest energy transitions at λmax 300–330 and 390–440 nm, respectively.
Reflection and Photoconduction Spectra of the Single Crystals of Perylene-TCNQ 1:1 and 3:1 Molecular Complexes
Authors: Ishii Kikujiro , Yakushi Kyuya , Kuroda Haruo , Inokuchi Hiroo 
Published: July 2006

Abstract
Crystal absorption spectra of the two modifications of the perylene-TCNQ (7,7,8,8-tetracyanoquinodimethan) complex were derived from reflection spectra by the Kramers-Kronig transformation and are discussed in relation to the differences in the crystal structures. The spectral response of photoconduction does not show any efficient photocarrier generation in the lowest charge-transfer band region in either modification. However, the rise of the photocurrent of both modifications was found to obey an empirical equation, Y∝(E–Eth)2.5, where Y is the quantum yield of the photocarrier generation, E is the photon energy, and Eth is the threshold energy. Eth of the two modifications is almost the same and falls in the energy region a little above the lowest charge-transfer band. Efficiencies of the carrier generation, on the other hand, are quite different for the two modifications. These photoelectrical characters are discussed in connection with the optical spectra and also with the data of photoelectron emission.
Crystal Structure of (−)474CD mer-{N-(2-Aminoethyl)-1,3-propanediamine}(diethylenetriamine)cobalt(III) Iodide Monohydrate, (−)474CD mer-[Co(aepn)(dien)]I3·H2O
Authors: Ishii Minoru , Sato Shoichi , Saito Yoshihiko , Nakahara Masayoshi 
Published: July 2006

Abstract
The crystal structure of (−)474CD mer-[Co{N-(2-aminoethyl)-1,3-propanediamine}(diethylenetriamine)]I3·H2O has been determined by means of X-ray diffraction. The crystal is monoclinic, with a space group of P21, a=9.662(2), b=14.602(2), c=8.201(3), β=112.87(4)°, and Z=2. The structure was solved by the Patterson-Fourier method and refined by the full-matrix least-squares method, which yielded an R value of 0.060 for the 2441 observed reflections. Each ligand molecule acts as a terdentate with meridional configurations. The absolute configuration of the coordinated asymmetric nitrogen atom in N-(2-aminoethyl)-1,3-propanediamine was determined to be R. The six-membered chelate ring in N-(2-aminoethyl)-1,3-propanediamine adopts a chair conformation, and the conformation of the five-membered chelate ring is δ. The conformations of the two five-membered chelate rings formed by diethylenetriamine are δ and λ, and the N(secondary)-H bond is oriented toward the six-membered chelate ring formed by N-(2-aminoethyl)-1,3-propanediamine.
Diene-transmissive Diels-Alder Cycloaddition Reaction of Bis(silyloxy) Cross-conjugated Trienes
Authors: Tsuge Otohiko , Wada Eiji , Kanemasa Shuji , Sakoh Hirohiko 
Published: July 2006

Abstract
Multiple Diels-Alder reaction of bis(silyloxy) cross-conjugated trienes is presented. Two trienes, 3-benzylidene- and 3-(methoxymethylene)-2,4-bis(trimethylsilyloxy)-1,4-pentadiene, undergo two sequential Diels-Alder cycloadditions with a variety of dienophiles forming hydronaphthalene rings. Some characteristics of this reaction have been discussed in terms of stereo-, regio-, and chemoselectivity. It is proposed that this process is referred to as “diene-transmissive Diels-Alder reaction”.