bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Retention of Decatungstates upon Photoreduction
Authors: Sasaki Yoh , Yamase Toshihiro , Ohashi Yuji , Sasada Yoshio 
Published: July 2006

Abstract
The crystal structures of oxidized and photoreduced decatungstates are compared. Three specimens of decatungstate complexes were prepared in mixed solvents of H2O–CH3CN and were characterized by X-ray diffraction. Unit cell parameters are as follows: (C6H16N)4[W10O32]·2CH3CN; DECA Mr=2841.4, monoclinic, P21⁄n, a=14.617(2), b=17.783(3), c=11.755(2) Å, β=100.27(2)°, V=3006.5(9) Å3, Z=2; (C6H16N)4[H1.5W10O32]·8H2O; RED1 Mr=2905.4, monoclinic, P21⁄n, a=15.902(3), b=12.233(2), c=15.673(4) Å, β=93.76(2)°, V=3042(1), Å3 Z=2; Na4[H1.8W10O32]·14H2O; RED2 Mr=2696.7, monoclinic, C2⁄m, a=16.123(5), b=12.636(3), c=12.168(4) Å, β=117.40(2)°, V=2202(1) Å3, Z=2; There is no obvious change in the anion frame among the three decatungstate complexes. Photoreduced decatungstates may coordinate protons which neutralize excess charge injected into anions. It is concluded that the structure of W10O32 is not largely altered up to two-electron reduction.
Photoreactions of N-Methyl-1,2-naphthalenedicarboximide with Dienes. Formation of Naphthazepinediones and Their Secondary Reactions
Authors: Kubo Yasuo , Toda Rie , Araki Takeo 
Published: July 2006

Abstract
In the photolysis of a benzene solution of N-methyl-1,2-naphthalenedicarboximide (5) in the presence of dienes, i.e., 2,3-dimethyl-1,3-butadiene and 1,3-butadiene, insertion of one of the double bond in the dienes into a C(=O)–N bond of 5 was observed to give naphthazepinediones. These products were found to convert further into cyclobutanes and α,β-unsaturated ketones via photochemical intramolecular cycloaddition and via hydrogen migration, respectively.
Stereospecific and Nucleophilic Additions of 2- and 3-Thienylmethylene. Reactions of 2- and 3-Thienylmethylene with cis- and trans-Stilbene, Dimethyl Maleate, Dimethyl Fumarate, and Styrene Derivatives
Authors: Saito Katsuhiro , Ishihara Hiraku , Murase Toyonobu , Horie Yoichi , Maekawa Etsuro 
Published: July 2006

Abstract
The addition reactions of 2-thienylmethylene with cis- and trans-stilbene afforded stereospecific adducts, respectively, indicating that the multiplicity of the carbene is singlet. The nucleophilicity of the carbenes was elucidated by an investigation of the relative rate ratio of the reactions of the carbene with various styrenes. An analogous result was afforded by reactions of 3-thienylmethylene with the same olefins mentioned above.
Quantitative Analysis of Partition Behavior of Substituted Phenols from Aqueous Phase into Liposomes Made of Lecithin and Various Lipids
Authors: Miyoshi Hideto , Maeda Hiroaki , Tokutake Nobuya , Fujita Toshio 
Published: July 2006

Abstract
The partition coefficient of a series of substituted phenols in lecithin-liposome–water systems, P(L/W), was quantitatively analyzed by use of physicochemical molecular and substituent parameters. The effects on the P(L/W) value of the incorporation of cholesterol and charged lipids such as cardiolipin or stearylamine into the liposomal membranes were examined with the perturbation of the bilayered membrane structure induced by these lipids being taken into account. The partition behavior of phenols was primarily decided by the hydrophobicity, represented in terms of the 1-octanol–water partition coefficient, P(O/W). The partitioned phenols seemed to be in membrane close to the interface. The steric and electronic effects of substituents on the partitioning into liposomes varied significantly depending upon the type of lipids incorporated. The variations in these effects reflect differences in the structure of the interfacial region of the lecithin bilayer modified by the incorporation of various lipids.
Kinetics of Oxidation of Pyridoxine by Chloramine-T in Acid Medium
Authors: Jayaram Beby , Made Gowda Netkal M 
Published: July 2006

Abstract
The kinetics of oxidation of pyridoxine (PRX) by chloramine-T (CAT) in the presence of hydrochloric acid (0.04–0.14 M) have been studied over the temperature range of 303–323 K. The rate of the reaction shows first-order dependence on each of CAT, PRX, and chloride ion concentrations. The reaction rate is independent of hydrogen ion concentration. Variations of ionic strength and dielectric constant of the medium have negligible effect on the rate. Addition of the reaction product, p-toluenesulfonamide, decreases the rate showing a negative first order dependence. The solvent isotope effect has been studied by using heavy water. The activation parameters, Ea, ΔH\ewq, and ΔS\ewq are computed from the reaction rates at various temperatures. The mechanism of PRX oxidation proposed and the rate law derived are consistent with the observed kinetics.
Excited-State and Ground-State Proton-Transfer Reactions in 5-Aminoindole
Authors: Sinha Hemant Kumar , Dogra Sneh Kumar , Krishnamurthy Mannam 
Published: July 2006

Abstract
Dual fluorescence emissions are observed when the electron-donating group (–NH2) is present at the position 5 of indole moiety. From the study of solvent effect and the large blue shift observed in the fluorescence spectra at 77 K, it is concluded that the long wavelength fluorescence band (480 nm) is assigned to the more polar state and the short wavelength band (350 nm) to the less polar state of 5-aminoindole (AI). Monocation is formed by protonating the amino group and no proton-induced fluorescence quenching of the neutral species is observed prior to its being protonated. This is mainly due to the shorter life of the conjugated acid–base pair. CNDO/S calculations indicate that dication is formed by protonating the C-3 position of the monocation of AI in the S0 state but position 4 of monocation of AI in the S1 state. Monoanion is formed by the deprotonation of &gt;NH group in the S0 state, but from the deprotonation of –NH2 group in the S1 state.
Reaction between Copper(II) Chloride and Active Carbon for the Formation of Solid Carbon Monoxide Adsorbent
Authors: Komiyama Makoto , Ando Hiroaki , Hirai Hidefumi 
Published: July 2006

Abstract
Evolution of hydrochloric acid on the preparation of carbon monoxide adsorbents from copper(II) chloride and active carbon has been experimentally confirmed. Relationship between the amount of hydrochloric acid evolved and the adsorbing capacity shows that the efficient adsorption by the adsorbents is attributable to the function of the copper(I) chloride, which is formed during the preparation by the reaction between copper(II) chloride and active carbon.
Ortho Substituent Effect of the Side-Chain Phenyl Group on the Dehydrogenation of Flavanones with 2,3-Dichloro-5,6-dicyano-p-benzoquinone
Authors: Hoshino Yukio , Takeno Noboru 
Published: July 2006

Abstract
Rates of the dehydrogenation of 2′-substituted flavanones with 2,3-dichloro-5,6-dicyano-p-benzoquinone were measured by means of HPLC analyses. All substituents at the ortho position of the side-chain phenyl group of flavanones showed a retarding effect on the reaction. A correlation analysis for the ortho effect using the linear combination model has led to a conclusion that the inductive effect is much more important than the steric and the resonance effect, and that the steric effect is slightly greater than the resonance effect.
The Effect of the Carbonyl Group, Phenyl Ring, and Ring Size of α-Iodo Cycloketones on the Nature of the Photochemical Carbon–Iodine Bond Cleavage
Authors: Šket Boris , Zupan Marko 
Published: July 2006

Abstract
UV irradiation of 2-iodo-3,4-dihydro-1(2H)-naphthalenone and 2-iodo-1-indanone has been found to involve competing radical and ionic photoprocesses. The carbonyl group, phenyl ring and ring size of cycloketones have an influence on the nature of the photochemical carbon–iodine bond cleavage.
Conductance of Potassium Iodide in Supercooled Water
Authors: Nakahara Masaru , Zenke Masanobu 
Published: July 2006

Abstract
The conductance of potassium iodide was measured in water as a function of concentration (between 2×10−3 and 10−2 mol dm−3) and temperature (between −6 and 0 °C). The effect of temperature on the mobility of such halide ions as I− and Cl− ions was discussed by taking the ionic residual friction coefficient Δζ, which was defined as the overall friction coefficient subtracted by the Stokes one for slip, instead of the conventional Walden product. We compared the experimental results with the predictions due to the Hubbard–Onsager dielectric friction theory. Of the monovalent ions so far studied, the iodide ion shows the largest negative value of Δζ with the largest positive temperature coefficient; their signs are opposite to those theoretically predicted. These findings were explained in terms of the special ionic transport mechanism called the passing-through-cavities.
Calorimetric and Spectrophotometric Studies of Chloro Complexes of Nickel(II) and Zinc(II) Ions in N,N-Dimethylformamide
Authors: Ishiguro Shin-ichi , Ozutsumi Kazuhiko , Ohtaki Hitoshi 
Published: July 2006

Abstract
Complexation of Ni(II) and Zn(II) with Cl− ions has been studied by calorimetry and spectrophotometry in N,N-dimethylformamide (DMF) containing 0.4 mol dm−3 (C2H5)4NClO4 as a constant ionic medium at 25 °C. Calorimetric titration curves obtained in each system were well-explained in terms of formation of [MCln](2−n)+ (n=1–4 and M2+=Ni2+ or Zn2+), and their formation constants, enthalpies and entropies were determined. Formation of the nickel(II) chloro complexes in DMF was also supported by spectrophotometry. In the nickel(II) chloride system, the stepwise enthalpy ΔH3° and entropy ΔS3° values are remarkably large and positive as compared with the ΔHn° and ΔSn° (n=1, 2, and 4) values. Individual electronic spectra of nickel(II) ion, [NiCl]+ and [NiCl2] are significantly different in both intensities and peak positions from those of [NiCl3]− and [NiCl4]2− over the range 300–850 nm. These thermodynamic and spectrophotometric results were explained in terms of formation of the octahedral [NiCl]+ complex as well as [Ni(dmf)6]2+ and of formation of the tetrahedral [NiCl3]− and [NiCl4]2− complexes in DMF. On the other hand, in the zinc(II) chloride system, the ΔSn° (n=1 and 2) values are large and positive, but the ΔSn° (n=3 and 4) values are significantly small. The corresponding ΔHn° (n=1 and 2) values are positive but the ΔHn° (n=3 and 4) values are significantly negative. It is thus postulated that the [ZnCln](2−n)+ (n=2 and 3) complexes have the tetrahedral coordination structure as well as the [ZnCl4]2− complex in DMF.
The Optical Resolution and Asymmetric Transformation of Dl-p-Hydroxyphenylglycine with (+)-1-Phenylethanesulfonic Acid
Authors: Yoshioka Ryuzo , Tohyama Masanori , Ohtsuki Osamu , Yamada Shigeki , Chibata Ichiro 
Published: July 2006

Abstract
Optically active 1-phenylethanesulfonic acid was found to be an efficient resolving agent for the optical resolution and asymmetric transformation of Dl-p-hydroxyphenylglycine. When Dl-p-hydroxyphenylglycine was resolved by the fractional crystallization of its diastereomeric salt with (+)-1-phenylethanesulfonic acid, less soluble d-p-hydroxyphenylglycine (+)-1-phenylethanesulfonate [d-HPG·(+)-PES] was obtained in a good yield. Soluble l-HPG·(+)-PES was easily epimerized into Dl-HPG·(+)-PES by heating it at 100 °C in glacial acetic acid in the presence of a small amount of salicylaldehyde. Under such epimerizing conditions, the asymmetric transformation of Dl-HPG·(+)-PES was attempted by simultaneously combining the fractional crystallization of the less soluble d-HPG·(+)-PES and the epimerization of the soluble l-HPG·(+)-PES. This asymmetric transformation was achieved successfully; that is, 80% of the Dl-HPG used as the starting material was converted into d-HPG.
Improvement of Porphyrin Photovoltaic Cells in Panchromaticities and Quantum Yields by Use of Tetrabenzoporphyrin Skeleton
Authors: Yamashita Kazuo , Harima Yutaka , Kubota Hideyuki , Suzuki Hitomi 
Published: July 2006

Abstract
Expansion of the porphyrin π electron system by using a tetrabenzoporphyrin (TBP) skeleton leads to better spectral match to the solar spectrum and high quantum yields when the porphyrins are used as sensitizers. Metallotetrabenzoporphyrins such as MgTBP and ZnTBP rank among the most efficient organic photoconducting materials studied so far.
Effect of Aryl Substituents on 2-Aryl-1,4,5,6,7,7-hexachloronorbornadiene–Quadricyclane Reversible Isomerization
Authors: Tomioka Hideo , Hamano Yukinobu , Izawa Yasuji 
Published: July 2006

Abstract
2-Arylhexachloronorbornadiene undergoes photoisomerization to the corresponding quadricyclane, which returns back to the norbornadiene upon heating without catalyst. Effect of aryl substituents on the thermal reversion suggests that both spin delocalization and polar effect equally contribute to the stabilization of the transition state.
Synthesis of Three Acyclic All-trans-Tetraterpene Diols, Putative Precursors of Bacterial Lipids
Authors: Chappe Bertrand , Musikas Hélène , Marie Dominique , Ourisson Guy 
Published: July 2006

Abstract
Three acyclic all-trans-tetraterpene diols, A, B, and C have been synthesized from geraniol (1), by a convergent scheme involving six different C10 synthons derived from geraniol, and coupling by known reactions of three different types: substitution of allylic chlorides by carbanions α to sulfones, duplication of allylic alcohols, and Pd(0)-catalyzed coupling of allylic carbonates with doubly stabilized carbanions. A, B, and C represent postulated phylogenetic precursors of known membrane reinforcers, and are the three possible distally dihydroxylated dimers of geranylgeraniol: tail-to-tail, head-to-head, and head-to-tail.
An ESR Study of 5-Formazanyl Copper(II) Complexes as an Analogy to Three Types of Copper-Containing Proteins
Authors: Kawamura Yoshiko , Deguchi Yasuo , Yamauchi Jun , Ohya-Nishiguchi Hiroaki 
Published: July 2006

Abstract
The Electron Spin Resonance(ESR) spectra of ten 5-formazanyl copper(II) complexes in toluene solutions have been observed at room temperature and at that of liquidnitrogen. The ESR(g⁄⁄ and A⁄⁄) and bonding(α2) parameters of the copper ion were greatly affected by substituting several groups at the ortho position of 1-phenyl ring of formazan. Based on these results, the complexes are classified into three groups: Group I, in which A⁄⁄\simeq0.012–0.013 cm−1 and α2\simeq0.5; Group II, in which A⁄⁄\simeq0.017 cm−1 and α2\simeq0.7, and Group III, in which two copper ions are interacting. It is clarified that they correspond nicely to three types of copper-containing proteins previously investigated.
The Effect of “Chemiluminescence Quenching” on the Chemiluminescence Quantum Yields from 9-Benzylacridine and 9-Benzyl-10-methylacridinium Iodide
Authors: Kamiya Isao , Sugimoto Takashi , Yamabe Kuniaki 
Published: July 2006

Abstract
A visible chemiluminescence (CL) has been found from the air oxidation of 9-benzyl-10-methylacridinium iodide, in contrast to the case of 9-benzylacridine, from which only a feeble CL could be detected. The difference in the CL quantum yields from the acridinium salt and acridine is interpreted in terms of a “CL quenching” of the chemiexcited species by benzaldehyde generated simultaneously in a solvent cage.
The 1H and 13C NMR of the Tetraphenylcyclopentadienone Dianion
Authors: Hirayama Masatoshi , Koiwai Kazuhiko , Takemura Kazumi , Kobayashi Masaaki , Seki Akihiko , Takahashi Kensuke 
Published: July 2006

Abstract
The stable monomer dianion of the title compound was formed by the contact of its tetrahydrofuran-d8 or 1,2-dimethoxyethane-d10 solution with sodium metal at 5 °C and was characterized by means of its 1H and 13C NMR spectra.
Studies of the Stabilities of Scandium, Yttrium, and Lanthanoid-Ion Complexes of 2-Nitroso-5-(N-propyl-3-sulfopropylamino)phenol
Authors: Yoshida Isao , Sagara Fumio , Ueno Keihei 
Published: July 2006

Abstract
The stability constants of the 1:1 complexes formed by 2-nitroso-5-(N-propyl-3-sulfopropylamino)phenol (NPSAP:H2L) with tervalent scandium, yttrium, and lanthanoids, but not promethium, have been determined potentiometrically in aqueous solutions at an ionic strength of 0.1 with potassium nitrate and at 25 °C. The stability constants of the 1:1 complexs increased with the increase in the atomic number of the lanthanoid, with the slight decrease at gadolinium. The stability constant of the 1:1 complex of scandium was the highest among the metal complexes investigated, while that of the yttrium complex was found to be between those of the cerium and praseodymium complexes.
The Thermal Decomposition of 1-Methyl-1-phenylethyl 2,2-Dimethylperoxypropionate in Cumene
Authors: Komai Takeshi , Kato Kenji , Matsuyama Kazuo 
Published: July 2006

Abstract
The thermal decomposition of 1-methyl-1-phenylethyl 2,2-dimethylperoxypropionate was studied in cumene. Based on the kinetic parameters and the decomposition products, it was concluded that the peroxyester was decomposed mainly by means of the radical process in cumene.
The Lowest Triplet States of 2-Amino- and 2-Amino-d2-pyrimidines
Authors: Nibu Yoshinori , Maehara Masayoshi , Shimada Hiroko , Shimada Ryoichi 
Published: July 2006

Abstract
The vibrational analyses of the sublevel phosphorescence spectra of 2-amino- and 2-amino-d2-pyrimidines were made. The result shows that the lowest triplet 3A1(π, π*) state is strongly perturbed by closely lying 3B1(n, π*) and 3A2(n, π*) states and the polarization of the very weak 0–0 bands in the dark sublevel spectra suggests that the symmetry of the molecular structure in the lowest triplet state is slightly lowered from the point group C2ν to the C2.
Radical Cyclization to Seleno-Substituted Thiahomoprotoadamantanone and Its Unexpected Conversion to the Vinyl Selenide
Authors: Toru Takeshi , Kanefusa Toshiya , Maekawa Eturô , Ueno Yoshio , Kondo Kazumoto , Eguchi Shoji 
Published: July 2006

Abstract
Heating Se-phenyl bicyclo[3.3.1]non-6-ene-3-(selenothioperoxy)carboxylate with AIBN gives 5-phenyl-seleno-3-thia-2-homoprotoadamantan-2-one which is unexpectedly converted to the vinyl selenide via the selenoxide by oxidation with hydrogen peroxide or mCPBA.
Efficient Reduction of Acyl Chlorides with Zn(BH4)2/N,N,N′,N′-Tetramethylethylenediamine
Authors: Kotsuki Hiyoshizo , Ushio Yasuyuki , Yoshimura Naka , Ochi Masamitsu 
Published: July 2006

Abstract
Aliphatic and aromatic acyl chlorides were efficiently reduced to give the corresponding alcohols when treated with Zn(BH4)2 in the presence of N,N,N′,N′-tetramethylethylenediamine. The reactions with other bases were also examined.
Structure of Physalin M Isolated from Physalis alkekengi var. francheti
Authors: Kawai Masao , Ogura Toichi , Nakanishi Masaki , Matsuura Taketoshi , Butsugan Yasuo , Mori Yuji , Harada Ken’ichi , Suzuki Makoto 
Published: July 2006

Abstract
The structure of physalin M, isolated from Physalis alkekengi var. francheti was determined as 7-deoxyphysalin L by spectroscopic studies and chemica correlation with a known compound. Physalin M exhibitec weak cytotoxicity against tumor cells.
The Determination of a Small Amount of Biological Constituent by the Use of Chemiluminescence. XIII. High Sensitive Metal Chelate Affinity Chromatography
Authors: Hara Tadashi , Tsukagoshi Kazuhiko , Yoshida Tatsunari 
Published: July 2006

Abstract
A chemiluminescence detector using a 1,10-phenanthroline–hydrogen peroxide–copper(II) system was successfully combined with a metal chelate affinity column. A mixture comprising bovine serum albumin, lysozyme, and bovine serum γ-globulin as model proteins was completely separated by the pH-gradient elution method on a TSK gel Chelate-5PW adsorbed with zinc ions, also, each protein could be quantitatively determined. According to the present method, using a 0.4 cm3 column of bed volume, 1) the determinable concentration range for bovine serum γ-globulin was formed to be 1.0×10−4–1.0×10−1 g dm−3 with a detection limit of 5 ng for a 50 mm3 of injection volume, 2) the recovery of 1.0×10−3 g dm−3 bovine serum γ-globulin was 85% with 7.9% of the coefficient of variation (n=5), and 3) the time necessary for an analysis was about 50 min. The present method was about 200 times more sensitive than that using an ultraviolet detector and was also applicable to a human serumn sample.
Mechanistic Study on the Photochemical Conversion of Disilanyliron(II) Complexes to Monosilyliron(II) Complexes
Authors: Tobita Hiromi , Ueno Keiji , Ogino Hiroshi 
Published: July 2006

Abstract
Photolysis of a C6D6 solution of CpFe(CO)2SiMe2SiMe3 (Cp=η5-C5H5) or (MeCp)Fe(CO)2SiMe2SiMe3 (MeCp=η5-C5H4Me) resulted in the formation of monosilyl derivative, CpFe(CO)2SiMe3 or (MeCp)Fe(CO)2SiMe3 in 64 or 59% yield, respectively, together with small quantities of ferrocene and Cp2Fe2(CO)4 or their methylated derivatives. The yield of CpFe(CO)2SiMe3 increased to 88% when the photolysis was carried out under a carbon monoxide atmosphere, while decreased to 22% when argon was vigorously bubbled through the reaction mixture. These results are consistent with a mechanism involving dissociation and recombination of a carbonyl ligand which are common processes in photoreactions of transition-metal carbonyl derivatives. Dimethylsilylene moiety released during the photolysis was tried to be trapped with a hydrosilane, diene, and cyclotrisiloxane, but none of the expected products from the trapping reactions was detected, even in a trace amount. Photolysis of CpFe(CO)2SiMe2SiMeEt2 afforded, accompanying alkyl migration between silicon atoms, CpFe(CO)2SiMeEt2, CpFe(CO)2SiMe2Et, and CpFe(CO)2SiMe3 in 26, 33, and 4% yields, respectively. Photolysis of a 1 : 1 mixture of CpFe(CO)2SiMe2SiMeEt2 and (MeCp)Fe(CO)2SiMe2SiMe3 provided only products expected from intramolecular alkyl migration mechanism. A possible mechanism involving silyl(silylene)iron intermediates is proposed to explain these results.
The Synthesis, and the Crystal and Molecular Structures of Tetraethylammonium [Aquaheptakis(thiocyanato)lanthanoidate(III)], [(C2H5)4N]4[M(SCN)7(H2O)], (M=La, Ce, Pr; Nd, Dy, Er): The Complexes in a Cubic Octa-Coordination Geometry
Authors: Tateyama Yoshikuni , Kuniyasu Yasumitsu , Suzuki Yasuo , Ouchi Akira 
Published: July 2006

Abstract
The title complexes have been synthesized, and their crystal and molecular structures were determined by the X-ray diffraction method using their single crystals. Among them, the crystals of the La, Ce, and Pr complexes are isomorphous; cubic, space group Pm\bar3, Z=1, and the cell constants of the Pr complex, for example, are a=11.513(2) Å, U=1526.1(5) Å3, and the final R value was 0.093. The Nd, Dy, and Er complexes, another group of the isomorphous complexes obtained almost by the same synthetic method, are tetragonal, space group I4/m, Z=2, and the cell constants of the Er complex, for example, are a=1.564(2), c=22.627(4) Å, U=3026(3) Å3, and the final R value was 0.071. The coordination geometry around the metal atoms of both types of complexes are almost the same: seven thiocyanato nitrogen and one water oxygen atoms are coordinated in a cubic geometry, being disordered as if each ligating atomic position is equally occupied by 1/8 atom of the water oxygen and 7/8 atoms of the thiocyanato nitrogen. In the lattice of the former three complexes, the tetraethylammonium nitrogen atoms occupy all Cl− ionic positions of the NaCl-type lattice, while the metal atoms only the apex Na+ ionic positions; not the face-center ones. The unit cells of the latter three complexes are apparently consist of the two former cubic type cells being piled on the c-axis direction, where the arrangement of the atoms is different from the former only on the plane where two original cells are contact: metal and ammonium nitrogen positions slide 0.5 both to a- and b-axis directions. Thus each metal atom of the both type complexes is surrounded by six tetraethylammonium nitrogen atoms on both sides of the a, b, and c-axis directions.