bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature Dependence of Fluorescence Spectra and Fluorescence Polarization of Some Organic Compounds in Polar Solvents. The Franck-Condon Excited States
Authors: Baba Hiroaki , Mugiya Chie 
Published: July 2006

Abstract
Fluorescence and absorption spectra and fluorescence polarization were measured at different temperatures, ranging from room temperature to 77°K, for 9,10-diazaphenanthrene, 2-naphthol and 2,3-naphthalenediol in polar solvents. At about 120°K, the fluorescence spectra shifted rapidly to the blue as the temperature was lowered. This observation is quantitatively interpreted on the basis of a kinetic scheme involving competitive rate processes, viz., radiative transition from the Franck-Condon excited state, as defined for the dipole orientation of the solvent, and relaxation of the Franck-Condon state into the equilibrium excited state. The Franck-Condon destabilization energies are evaluated from the observed blue shifts. Along with the fluorescence blues hifts, the degrees of polarization increased rapidly, but at a somewhat higher temperature of about 140°K. This phenomenon is related to the rotational relaxation of the solute molecule, and is discussed in comparison with the fluorescence blue shift.
The Solution Properties of Poly-o-methylstyrene
Authors: Matsumura Kimiyoshi 
Published: July 2006

Abstract
The solution properties of poly-o-methylstyrene in toluene were measured by the light-scattering and viscosity methods, and the results were compared with those obtained from poly-o-chlorostyrene and other polystyrene derivatives. The dependencies of the intrinsic viscosity, the second virial coefficient, and the end-to-end distance of the polymer chain on the molecular weight are as follows:
& [η]=9.22×10^-5·M_w^0.72(dl/g), A_2=3.89×10^-2·M_w^-0.38 (mol·cc/g^2)
& and 〈L^2〉^1/2=0.197×M_w^0.62 (Å).
It was made clear that the unperturbed dimension of poly-o-methylstyrene was larger than that of poly-p-methylstyrene, and that the cause of this difference is the large steric repulsion between the side groups of the former. Moreover, the unperturbed dimension of poly-o-methylstyrene was smaller than that of poly-o-chlorostyrene. From these results, it is considered that the large extension of poly-o-chlorostyrene was affected by the electrostatic repulsion between the side groups.
NMR Study of Amino Acids and Peptides; Glycine and Valine Peptides
Authors: Nagai Makoto , Nishioka Atsuo , Yoshimura Juji 
Published: July 2006

Abstract
The PMR spectra of 22 amino acids and peptides were measured in a D2O solution. From the change in the NMR parameters in amino acids and their di- and tripeptides, it has been concluded that a tripeptide is a good model for polypeptides. The chemical shift of the α-proton of an aminoacid residue in tripeptide can be obtained from those of amino acid and dipeptide. The spin-spin coupling constant of an amino acid grows larger, and the population of a trans rotamer becomes larger, as its amino (or carboxyl) group forms a peptide bond. The PMR spectra of two diasteroisomers of valyl-valyl-valine were also measured, and the influences of the configuration of an aminoacid residue on the NMR parameters of its peptides were investigated.
The Chemical Behavior of Low Valence Sulfur Compounds. V. Decomposition and Oxidation of Tetrathionate in Aqueous Ammonia Solution
Authors: Naito Kunishige , Shieh Mu-Chang , Okabe Taijiro 
Published: July 2006

Abstract
The decomposition and oxygen oxidation of tetrathionate in aqueous ammonia solution have been investigated. In the decomposition, thiosulfate, sulfate and sulfamate were formed through penta- and trithionate as intermediate compounds. The molar ratio of the products (SO42−+SO3NH2−)/S2O32− was roughly equal to 2/7, where 0.1n ammonia solution was used. The deficient use of ammonia made the solution neutral or weakly acidic and the precipitation of sulfur and the formation of higher polythionates were observed. The polythionate was detected by means of TLC (Thin Layer Chromatography). In the oxidation, tetrathionate was supposed to go through the following three sequent steps. 1) Decomposition of tetrathionate to form thiosulfate, tri- and pentathionate, and further decomposition of pentathionate to thiosulfate. 2) Oxidation of thiosulfate to tetrathionate and partly to sulfate. 3) Decomposition of trithionate to form sulfate, sulfamate and thiosulfate.
Derivatographic Studies on Transition Metal Complexes. III. The Thermal trans-cis Isomerization of [CoCl2pn2](H5O2)Cl2 in Solid-Phase
Authors: Tsuchiya Ryokichi , Murai Kiyoko , Uehara Akira , Kyuno Eishin 
Published: July 2006

Abstract
The thermal decomposition of trans-[CoCl2pn2](H5O2)Cl2 in solid-phase was measured by derivatography and the isothermal method with a thermobalance. It was found by the latter that dehydration and dehydrochlorination took place with partial isomerization below 170°C. The rate of isomerization gradually increased with temperature until it became equal to the rate of dehydration and dehydrochlorination above 170°C. The activation energies for dehydration and dehydrochlorination and for isomerization were calculated from the isothermal measurement below 170°C to be 10 kcal/mol and 23 kcal/mol, respectively. The activation energy obtained from DTA curve analysis at about 144°C in the derivatogram was 33 kcal/mol. The reaction was explained in terms of “aquation-anation” mechanism. Since the trans-cis isomerization in anhydrous state at 180°C gave a larger activation energy in DTA analysis, the “twisting” mechanism might be preferable to “aquation-anation” for the reaction.
Studies on the Baudisch Reaction. II. The Copper(II)-Hydroxylamine Complex
Authors: Tanimoto Iwao 
Published: July 2006

Abstract
Kinetic investigation of the Baudisch reaction indicates that the reaction follows first-order kinetics, and the isokinetic temperature lies at −11°C. Both kinetic studies and product studies require the formation of a phenol-copper-hydroxylamine-hydrogen peroxide complex during the course of the reaction. It was found that the yield of o-nitrosophenol which is the main product of the Baudisch reaction is counterbalanced by that of catechol according to the pH of the reaction system. Maximum yield of o-nitrosophenol is attained in the lower pH region (pH=2.5–3.5). Catechol which is the main product in the higher pH region (pH&gt;4) seems to be produced through the same complex.
Bis-Type Cobalt(III) and Chromium(III) Complexes with Related Compounds of Iminodiacetic Acid
Authors: Uehara Akira , Kyuno Eishin , Tsuchiya Ryokichi 
Published: July 2006

Abstract
The geometrical structures and some properties of the following complexes were investigated: K[Co(ida)2]·H2O (I), K[Co(ida)2]·2H2O (II), K[Cr(ida)2]·3H2O (III), Ba[Cr(ida)2]2·6H2O (IV), K[Co(mda)2] (V), K[Cr(mda)2] (VI), K[Co(eda)2]·H2O (VII) and K[Cr(eda)2]·H2O (VIII), where ida, mda and eda are the abbreviations of iminodiacetate, methyliminodiacetate and ethyliminodiacetate ions, respectively. IV, VII and VIII are new compounds. On the basis of electronic spectra, it was found that VII and VIII have the trans form with respect to nitrogen atoms in the ligands, and IV, the cis form. Comparison of the properties and structures of the cobalt-(III) complexes with those of the corresponding chromium(III) complexes were also made.
Liquid Phase Chlorination of Olefins with Cupric Chloride
Authors: Koyano Takashi 
Published: July 2006

Abstract
Reactions of olefins with cupric chloride were studied in methanol at 100–140°C. The reactivity of olefins was in the order, ethylene&gt;propylene&gt;1-butene&gt;2-butenes. A considerable amount of 1-chloro-2-methoxy compounds were found in the reaction products of 1-olefins. Competitive formation of dichloride and methoxychloride was suggested. Chlorination of 2-butenes leads to meso- and dl-2,3-dichlorobutanes, their ratio being invariable regardless of the starting material cis- or trans-2-butene. The mechanism is discussed in terms of ionic intermediates.
The Photoreaction of p-Substituted β-Benzoylacrylic Acids
Authors: Sugiyama Noboru , Kashima Choji , Kataoka Hiroshi , Tanaka Keiko 
Published: July 2006

Abstract
This paper will describe the photoreaction of trans-β-(p-ethylbenzoyl)acrylic acid (II) in methanol to give 5-(p-ethylphenyl)-5-methoxy-2-oxo-2,5-dihydrofuran (III), β-(p-ethylbenzoyl)-α-methoxypropionic acid (IV), and its methyl ester (V). The kinetic study of this reaction has revealed that II gives III and IV parallel by the first-order reaction and that IV then changes into V. Furthermore, the irradiation of p-substituted β-benzoylacrylic acids has been studied. From the product ratio and the substituent effects at the para position, the mechanism of the photoreactions of γ-oxoacrylic acids in methanol is proposed. This mechanism is also supported by the HMO calculations.
The Insertion Reaction of Isoprene into Metal-Ethyl Bonds in Various Transition-Metal Salt-Ethylaluminum Compound System
Authors: Takegami Yoshinobu , Suzuki Toshimitsu , Shirai Takashi 
Published: July 2006

Abstract
The insertion reaction of isoprene into metal-ethyl bonds in various transition-metal salt (VCl4, Fe(AA)3, Co(AA)2, CoCl2, Ni(AA)2, or NiCl2-ethylaluminum compound (AlEt2Cl or AlEt3)) catalyst systems was studied. With the vanadium and the nickel catalysts, 2-methyl-2-hexene and 2-methyl- 1-hexene were mainly formed by the methanolysis of the reaction mixture, showing that metal alkenyls, (Remark: Graphics omitted.) and (Remark: Graphics omitted.) respectively, are formed in the reaction system. However, in the iron catalyst, only 2-methyl-2,5-hexadiene and 3-methyl-2,5-hexadiene were formed from (Remark: Graphics omitted.) and (Remark: Graphics omitted.) respectively by the elimination reaction. These results suggest that the stability of metal alkenyls decreases in the order: V&gt;&gt;Ni&gt;Co&gt;Fe.
Ribonuclease T1 Peptides. IV. Synthesis of a Protected Heptapeptide Corresponding to Sequence 17–23
Authors: Mitsuyasu Nobuo , Waki Michinori , Kato Tetsuo , Makisumi Satoru , Izumiya Nobuo 
Published: July 2006

Abstract
A protected heptapeptide corresponding to sequence 17–23 of ribonuclease T1, namely benzyloxycarbonyl-l-seryl-l-threonyl-l-alanyl-l-glutaminyl-l-alanyl-l-alanyl-glycine ethyl ester (XIV), was synthesized by two routes. One consisted of the coupling of benzyloxycarbonylseryl-threonine azide with a pentapeptide ester, alanyl-glutaminyl-alanyl-alanyl-glycine ethyl ester. The other consisted of the coupling of benzyloxycarbonyl-seryl-threonyl-alanine azide with a tetrapeptide ester, glutaminyl-alanyl-alanyl-glycine ethyl ester. These four peptide segments were built up by the method of stepwise synthesis. Optical rotations, melting points and chromatographic behavior of XIV prepared by these two routes were found to be identical. Stereochemical homogeneity of the protected heptapeptide ester XIV was established by the digestion of the deblocked heptapeptide ester with leucine aminopeptidase.
Tri(hetero)substituted Carbonium Ions. I. Neighboring-Group Participation of the N,N-Dimethyldithiocarbamate Function Involving the Intermediacy of 2-Dimethylamino-1,3-dithiolanylium Ion
Authors: Nakai Takeshi , Ueno Yoshio , Okawara Makoto 
Published: July 2006

Abstract
The equimolar reaction of 1,2-dichloroethane with sodium N,N-dimethyldithiocarbamate was studied in various solvents. As major products, ethylene bis(N,N-dimethyldithiocarbamate) and 2-dimethylamino-l,3-dithiolanylium salt (the perchlorate or the tetraphenylborate) were obtained in yields, largely varying with the solvent used. On the basis of the solvent effect on the product ratio, and kinetic experiments it has been verified that neighboring-group participation of the N,N-dimethyldithiocarbamate function would be involved through the intermediacy of the isolated anchimeric carbonium ion, and that such participation is more predominant in nonpolar aprotic solvents such as dioxane and tetrahydrofuran. The mechanism of the reaction between 2-dimethylamino-l,3-dithiolanylium ion and the dithiocarbamate anion was established.
Synthetic Studies of Bacitracin. VI. Synthesis of Unprotected Thiazoline Peptides
Authors: Hirotsu Yoshihiro , Shiba Tetsuo , Kaneko Takeo 
Published: July 2006

Abstract
For a total synthesis of bacitracian A, a synthetic method to secure unprotected thiazoline peptides must be established. 2-Aminomethyl-R-Δ2-thiazoline-4-carboxamide, 2-aminomethyl-R-Δ2-thiazoline-4-carboxylic acid, 2-aminomethyl-R-Δ2-thiazoline-4-carbonyl-l-leucine were synthesized by either the iminoether coupling method or by the dehydration method using N-benzyloxycarbonyl group and benzyl ester as protecting groups.
Studies on Associated Solutions. I. Excess Volume of Binary Systems of Alcohols with Various Organic Liquids
Authors: Nakanishi Koichiro , Shirai Hideko 
Published: July 2006

Abstract
Excess volumes of mixing have been determined at 25.00°C by pycnometry for eleven binary solutions of methanol and two binary solutions of ethanol with organic liquids. The second components include three aliphatic amines, n-butyraldehyde, ethyl acetate, isopropyl ether, anisol, chlorobenzene, acetonitrile, pyridine and nitromethane. The excess volumes of binary solutions containing aliphatic alcohols, which are evaluated from the available density data, were critically reviewed and compared with the present results.
Some Semi-Empirical SCF MO Calculations on Norbornadiene, Norbornene, and Their 7-Cations
Authors: Konishi Hideyuki , Kato Hiroshi , Yonezawa Teijiro 
Published: July 2006

Abstract
Using a semi-empirical SCF MO method for valence electron systems proposed previously by the present authors, the electronic structures of norbornadiene (NBD), norbornene (NBE), and their 7-cations are discussed, together with the configurational problem of the 7-cations. In NBE and NBD, the interaction between the π AO’s in the double bond and the AO’s of the other parts of the molecules is made clear by the charge densities and the bond orders. For the first electronic transition assigned to a π–σ* or σ–π* in NBD, the present calcuation gives a rather larger excitation energy than does the experiment. For 7-norbornenyl and 7-norbornadienyl cations, the presence of structures distorted from NBE and NBD respectively can theoretically be concluded. The delocalization of the positive charge and the bonding interaction between the bridged carbon atom and the double bond carbon atoms support the concept of the so-called non-classical carbonium ions.
Hydrogen Ion Titration of Poly-S-carboxymethyl-l-cysteine
Authors: Ikeda Shoichi 
Published: July 2006

Abstract
Potentiometric titration curves have been determined for aqueous solutions of poly-S-carboxymethyl-l-cysteine. A pH-induced transition of the polymer conformation is manifest from the occurrence of a transition region around pH 5, where the solution has an essentially infinite buffer action. The titration curve at higher ionization corresponds to that of a random coil. At lower ionization the polymer is associated to form a β-structure and its titration behavior is qualitatively accounted for by the Gouy model for a uniformly charged sheet. Deviation from the model would partly be ascribed to the aggregation of sheets in the β-form. The standard free energy of transition from random coil to β-form has been estimated for the unchanged polymer and is found to depend on the molecular weight of polymer. It is suggested that fine structure of the β-form and its mode of aggregation vary with polymer chain length.
Metal Halide Complexes with Trimethylstibine Sulfide
Authors: Saito Takayuki , Otera Junzo , Okawara Rokuro 
Published: July 2006

Abstract
2 : 1 complexes of trimethylstibine sulfide (TMSS) with zinc(II), cadmium(II), mercury(II) and cobalt(II) halides were prepared. 1 : 1 complexes were also obtained with cadmium bromide and mercuric iodide. On the basis of infrared spectra, it was found that TMSS coordinates to the metal through the sulfur atom and that Hg(TMSS)I2 has a sulfur-bridged structure. The electronic spectral parameters of the tetrahedral Co(TMSS)2X2 (X=Cl, Br and I) complexes are quite close to those of trimethyl-phosphine and -arsine sulfide complexes. These results indicate that for Co–S interactions, polarizability of the thioxo ligand is more important than polarity.
Kinetics for Reversible Menschutkin Reactions. The Effects of Variations in Reactant Structures on the Sensitivity of the Reaction Rate to Solvent Variations
Authors: Matsui Takeki , Tokura Niichiro 
Published: July 2006

Abstract
The reaction rates and equilibrium constants for quaternization of N,N-dimethylaniline and its derivatives with methyl iodide have been measured in acetonitrile, acetone, tetrahydrofuran, nitrobenzene, benzene, benzyl alcohol, and methanol at various temperatures. There is an approximate tendency for the solvent dependence of the reaction rates to diminish linearly with increasing reactivity of nucleophile. This could be interpreted in terms of the theory of an absolute reaction rate and of the concept of the rise of interaction term. In this connection it was proposed that such a problem must be considered in terms of the unitary term of rates. Using the data of rates of the reaction between pyridine and methyl iodide in various solvents, the activity coefficients of dimethylaniline and its derivatives in methanol relative to that of pyridine are estimated. Some inferences have been drawn concerning the nature of SN2 transition state from effects of solvents on both rates and equilibria.
Synthesis of Adamantane Derivatives. IX. The Ritter Reaction of 1-Hydroxymethyladamantane with Acetonitrile
Authors: Sasaki Tadashi , Eguchi Shoji , Toru Takeshi , Ito Katsumi 
Published: July 2006

Abstract
The Ritter reactions of 1-hydroxymethyladamantane (1) and 3-homoadamantanol (14) with acetonitrile in coned, sulfuric acid were investigated. Two products, N-3-homoadamantyl acetamide (2) and N-1-adamantylmethyl acetamide (3) were isolated. Their total- and relative yields were determined in various reaction conditions by GLG analysis, indicating the facile conversion of N-3-homoadamantyl acetonitrilium cation (12) into N-1-adamantylmethyl acetonitrilium cation (13).
Reaction of Glycylglycine with Formaldehyde in the Presence of Cupric Ion
Authors: Noda Kosaku , Bessho Motoaki , Kato Tetsuo , Izumiya Nobuo 
Published: July 2006

Abstract
The reaction mixture of glycylglycine with formaldehyde in an alkaline aqueous solution containing cupric ion at 100°C gave seven ninhydrin positive components which were identified as follows; α-hydroxymethylserine, serine, glycine, 3-carboxymethyl-4-imidazolidone, α-hydroxymethylseryl-glycine, serylglycine and glycylglycine. The yield of serylglycine increased in proportion to the amount of cupric ion, whereas the yield of 3-carboxymethyl-4-imidazolidone was maximum when no cupric ion was added. A single-step synthesis in preparative scale of serylglycine or 3-carboxymethyl-4-imidazolidone under the best condition was achieved in a good yield.
Cyanoethylation of Copper, Nickel, and Palladium Glycinates
Authors: Shono Toshiyuki , Yamashoji Yuko , Shinra Koichiro 
Published: July 2006

Abstract
The present authors attempted the cyanoethylation of the methylene group in glycine by means of the reaction between acrylonitrile and copper, nickel, and palladium glycinates. The cyanoethylation of N-salicylideneglycinato-aquo copper (II) was also carried out. Four kinds of cyanoethylated complexes were obtained by changing the reaction conditions in the case of copper glycinate. In general, acrylonitrile reacted only with the hydrogen atoms of the amino group. In the case of N-salicylidene-glycinato-aquo copper (II), which has no hydrogen atom on the nitrogen atom, however, two methylene hydrogens were cyanoethylated with acrylonitrile.
Photochemical Reactions of Uranyl Ions with Organic Compounds. I. The Mechanism of the Uranyl Ion-Photosensitized Oxidation of Lactic Acid
Authors: Sakuraba Shukichi , Matsushima Ryoka 
Published: July 2006

Abstract
The photochemical reaction of lactic acid with uranyl ions in an aqueous solution was studied with radiations of 4050 and 4360 Å. The quantum yields and molar ratios of the reaction products were measured under various conditions. Two competing photo-reactions appeared to take place; through them lactic acid was oxidized to form pyruvic acid at a lower pH and to form acetaldehyde, with an evolution of carbon dioxide, at a higher pH. The results obtained can be well explained by assuming that the excitation of the uranyl lactate complex is involved in the formation of acetaldehyde and that a collision between lactic acid and the excited uranyl ion, without any complex formation, is involved in the formation of pyruvic acid.
Synthesis of Corticotropin Peptides. IX. Synthesis of [1-Glycine]-ACTH(1–18)-Octadecapeptide Amide
Authors: Otsuka Hideo , Shin Masaru , Kinomura Yasuhiko , Inouye Ken 
Published: July 2006

Abstract
The synthesis is decribed of an octadecapeptide, glycyl-tyrosyl-seryl-methionyl-glutamyl-histidyl-phenyl-alanyl-arginyl-tryptophyl-glycyl-lysyl-prolyl-valyl-glycyl-lysyl-lysyl-arginyl-arginine amide, corresponding to the first eighteen amino acid residues of corticotropin except for the amino end which has been replaced by a glycine for the serine in the native hormone. The protected end product was obtained by two different coupling procedures, the active ester and the catalyzed carbodiimide, from the amino-terminal decapeptide and the octapeptide of carboxyl end. The over-all yields of the peptide, for the final coupling, deblocking and purification steps, in the active ester and the carbodiimide procedures were approximately forty and thirty per cent, respectively. The synthetic octadecapeptide amide has been shown to possess a high adrenal corticotropic activity, which is comparable to that of the corresponding 1-serine octadecapeptide amide, and a lipolytic activity which is significantly lower than that of the 1-serine analog.
The Polarography of Alkyl Hydroperoxides in an Aqueous Solution
Authors: Hayano Shigeo , Shinozuka Noriko 
Published: July 2006

Abstract
The polarographic behavior of alkyl hydroperoxides was studied. n-Propyl, n-butyl, n-hexyl, and n-octyl hydroperoxide in an aqueous solution all show diffusion-controlled irreversible waves. The effect of the pH on the E1⁄2 and nα values is very small. The length of the alkyl group has a marked effect on E1⁄2 and nα. The longer the chain length of the alkyl group, the larger the value of nα and the more positive the E1⁄2. The linear free-energy relationship was found for the four alkyl hydroperoxides examined. The relation of Taft’s polar substituent coefficient to E1⁄2 has a negative reaction constant, which indicates a reaction promoted by high electron density in the reactive group. The electrode process seems to be the rupture of the –O–O– bond, followed by the protonation of the ions produced on the electrode.
cis-Tricarbonylbistriphenylphosphinemanganese and the Related Compounds
Authors: Nakayama Hiroaki 
Published: July 2006

Abstract
Tricarbonyl-methylcyclopentadienylmanganese(I) (I) gives two manganese carbonyl triphenylphosphine compounds when treated with triphenylphosphine in the presence of a sodium dispersion, with tetrahydrofuran used as the solvent. One compound is a known diamagnetic (CH3-C5H4)Mn(CO)2(PPh3)(II) (38% yield) formed by a ligand substitution reaction without any change in the oxidation number of the central manganese (+1). The other compound is a novel paramagnetic manganese(0) compound, cis-Mn(CO)3(PPh3)2 (III) (25% yield), which may be formed by a reductive phosphination reaction. A cis trigonal bipyramidal configuration, as in the case reported for Fe(CO)3(o-(AsMe2)2C6H4), is proposed for III on the basis of the results of infrared spectroscopy. The compound III gives the following derivatives: BrMn(CO)3(PPh3)2, VI, CH3Mn(CO)3(P-Ph3)2, VII, and Mn(CO)3(PPh3)2·1/2· CHCl3, VIII.