bluuebunny/crossref_metadata_2025 huggingface dataset:
The Linearity of the Substituent-induced Carbon-13 Chemical Shifts of α-Carbons with Charge Densities in Aromatic Side Chains. Semi-empirical Calculations for 4-Substituted Derivatives of Styrenes, α-Methylstyrenes, and Biphenyls
Authors: Niwa Jun
Published: July 2006

The contributions to 13C shifts from the diamagnetic term of the neighboring carbon atom and from the “ring-current” have been estimated by means of the equations given in a previous paper (J. Niwa, Bull. Chem. Soc. Jpn., 48, 118 (1975)). A semi-empirical expression has been derived for the substituent-induced 13C chemical shift in an aromatic side chain by considering such contributions in addition to the local diamagnetic and paramagnetic terms of the carbon atom in question. The applicability of the expression has been examined for α-carbons of 4-substituted derivatives of styrenes and α-methylstyrenes, and for 1′-carbons of 4-substituted biphenyls.
Studies of the Isomerization of Unsaturated Carboxylic Acids. IV. Base-catalyzed Rearrangements of β,γ-Unsaturated Esters to α,β-Isomers
Authors: Sakai Mutsuji , Nishikawa Sh\={u}ji , Koike Haruo , Sakakibara Yasumasa , Uchino Norito
Published: July 2006

Dimethyl methylenesuccinate, dimethyl citraconate, and dimethyl mesaconate mutually rearranged in the presence of triethylamine at room temperature. The rearrangement was found dependent on the polarity of the solvent and the basicity of the amine, and the rate was found to be first-order in both ester and amine. A mechanism has been proposed from a kinetic study.
An 1H and 13C NMR Spectroscopic Study of Ethyl 3-(2-PyrimidyI-amino)crotonate, Ethyl 3-(5-Bromo-3-pyridylamino)crotonate, N-(2-Pyrimidyl)-3-(methylamino)crotonamide, and N-(4-Methyl-2-pyridyl)-3-(methylamino)crotonamide
Authors: Kondo Michio
Published: July 2006

It has been found, from the 1H NMR spectra that two esters exist in an intramolecularly hydrogen bonded form (Z) in CDCl3 and DMSO solutions. Two amides, on the other hand, have been found to exist as a mixture of the Z and E isomers in DMSO solutions. H/D exchange at the olefinic site has been found to occur by the addition of D2O to the DMSO solutions of the amides, but not in the cases of the esters. The amide configurations are discussed. An interpretation of the 13C NMR spectra of these compounds is also given.
The Decomposition of N,N-Dichlorourethane by Copper: A Comparison with the Photolysis of Ethyl Azidoformate
Authors: Torimoto Noboru , Shingaki Tadao , Nagai Toshikazu
Published: July 2006

The reactions of N,N-dichlorourethane (1) with substrates, such as hydrocarbons and ethers, gave N-substituted urethanes (3) and urethane (4) in the presence of copper or copper(I) chloride. The reactions with aromatic hydrocarbons and cyclic ethers possessing an alkyl group at the α-position, however, gave no azepine and no alkoxyurethane respectively, in contrast to those of ethoxycarbonylnitrene generated from the azide. The reactions with the tertiary C–H bonds of cis- and trans-1,4-dimethylcyclohexanes proceeded non-stereospecifically, contrary to those of the nitrene. The reactions with alcohols led to high yields of 4, accompanied by the corresponding aldehydes, but afforded no O–H insertion product. The addition of a radical inhibitor, nitrobenzene, reduced the yield of 3, while it had no appreciable effect on the yield of 4. Furthermore, the reactions of N-chlorourethane with hydrocarbons also gave 3 and 4. These results suggest that the reaction of 1 with substrates proceeds not by a nitrene mechanism, but by a metal-radical mechanism.
Synthesis of [2-Serine, 8-VaIine]-Human Calcitonin
Authors: Nozaki Sukekatsu
Published: July 2006

The [2-serine, 8-valine]-analog of human calcitonin (1) was synthesized by the liquid phase method. Analog 1 was built up from five fragments with minimized protection for the side functional groups. These fragments were linked step wise to the C-terminal fragments by the azide method. A gel filtration was effectively applied for the purification of the resulting pep tide in each fragment condensation. Analog 1 had about the same hypocalcemic activity as that of human calcitonin. The result showed that the high activity of eel or salmon calcitonin 1 or 2 is not ascribable only to the amino acid sequence of their N-terminal decapeptide.
Cycloaddition Reactions of Thioacylketene Thioacetals and N-Thioacyldithioimidocarbonates
Authors: O-oka Masaharu , Kitamura Akihide , Okazaki Renji , Inamoto Naoki
Published: July 2006

Thioacylketene thioacetals (7) and N-Thioacyldithioimidocarbonates (8) undergo 1,4-cycloaddition reactions with active acetylenes and olefins to give six-membered heterocycles. Tetracyanoethylene behaves in a different way to afford conjugated dienes. In the reactions with diphenylketene and diazo compounds, 7 and 8 undergo different types of reactions; 7 gave products derived from 1,2-cycloaddition to the C=S bond, while 8 afforded 1,4-cycloadducts. Compound 7 was found to be more reactive than 8. The reactivity difference between 7 and 8 is discussed.
Fluorescence Spectra of 2-Pyridylbenzimidazoles. A Specific Interation of 2-(2-Pyridyl)benzimidazole with Ethanol
Authors: Kondo Michio
Published: July 2006

The fluorescence spectra of 2-(2-pyridyl)- (1a), 2-(3-hydroxy-2-pyridyl)- (1b), 1-methyl-2-(2-pyridyl)-, 2-(3-pyridyl)-, and 2-(4-pyridyl)-benzimidazole have been studied, and it has been found that their intensities are very strong, except for an ethanolic solution of 1a. It is likely, therefore, that a specific interaction, probably a bridge-type complexation of 1a with an ethanol molecule where imidazolic proton is explicitly involved, is responsible for the observed reduction in the fluorescence intensity for ethanol solutions. The fluorescence emission with a large Stokes’ shift of 1b is very strong, in ethanol as well as in other organic solvents tested, indicating a faster intramolecular proton transfer in the excited singlet state than intermolecular deactivation relaxation with ethanol molecules.
Charge-transfer Model in Considering the Reactivity of Heteroaromatic Nitriles with the Enolate Anion
Authors: Yamakawa Masumi , Kubota Tanekazu , Terui Yoshihiro , Honma Tsunetoshi , Tada Yukio
Published: July 2006

The reactivity of heteroaromatic nitriles with the enolate anion to give the enamino ketones was discussed on the basis of a reaction index calculated by the chargetransfer model and also using the total electron densities. The results were reasonable in interpreting the reaction mechanism.
The Raman Spectra of Diazines Adsorbed on Silicas
Authors: Yamamoto Yoichiro , Yamada Haruka
Published: July 2006

The Raman spectra of three diazines adsorbed on silicas have been measured. Spectra changes upon adsorption are interpreted as the result of hydrogen-bond formation between the surface OH group and the N atom of diazine. The order of the shifts of the Raman bands between three diazines is: 1,3-diazine>1,4-diazine>1,2-diazine.
Homoconjugation in BicycIo[3.2.1]octa-3,6-dien-2-yl and 6,9-Dihydro-5,9-methano-5H-benzocyclohepten-6-yl Radicals as Studied by Electron Spin Resonance
Authors: Kawamura Takashi , Takeichi Yoh’ichiro , Hayashida Shigeru , Sakamoto Masaaki , Yonezawa Teijiro
Published: July 2006

The radicals in the title and the bicyclo[3.2.1]oct-3-en-2-yl radical are examined with ESR. The extent of the odd electron delocalization due to π-π homo-conjugation in the bicyclo[3.2.1]octa-3,6-dien-2-yl radical is estimated to be in the order of a few per cent.
Complex Isomerism in 7-Methylbenzo[a]phenazinium Tetracyano-p-quinodimethanide
Authors: Matsunaga Yoshio
Published: July 2006

7-Methylbenzo[a]phenazinium tetracyano-p-quinodimethanide is dark green when it is prepared in boiling ethanol and violet when it is prepared in acetonitrile. Examination of the electronic, vibrational, and ESR spectra revealed that the former form is essentially non-ionic, and the latter, ionic.
Gas-chromatographic Measurements of Nitrous Oxide(N2O) in Air Using a Molecular Sieve Trap
Authors: Hirota Michio
Published: July 2006

The atmospheric mixing ratio of N2O was measured at the MRI, Koenji (Tokyo), between May and September, 1977, by a gas-chromatographic method. The mean value was 0.327 ppm. Judging from the measurements over the last 10 years, the atmospheric N2O seems to have increased about 20%.
(Hydroxyalkyl)pyridines as Bifunctional Catalysts. Dehydrobromination of 7-Bromocholesterol
Authors: Tachibana Yoji
Published: July 2006

In the dehydrobromination of 7-bromocholesterol, the reactions catalyzed by 2- and 3-(hydroxyalkyl)pyridines afforded 5,7-diene and 4,6-diene as the main product, respectively. The relative isomer ratio has been related to the position of the hydroxyalkyl group of the (hydroxyalkyl)pyridines. The results have been interpreted in terms of a concerted mechanism through a cyclic intermediate.
Reversible Oxygen Transfer Reactions between Sulfoxides and Sulfides. Relative Stabilities of Acyloxysulfonium Ions
Authors: Tanikaga Rikuhei , Nakayama Koji , Tanaka Kazuhiko , Kaji Aritsune
Published: July 2006

Sulfides and acyloxysulfonium ions generated from sulfoxides and trifluoroacetic anhydride undergo a reversible reaction at −80 °C. The acyloxysulfonium ions with electron-donating groups or less bulky groups were found to be more stable than those having electronwithdrawing or bulky substituents.
Preparation of Fluorinated Imidazole Derivatives Using Hexafluoro-1,2-epoxypropane
Authors: Hammoudat Hamdy A , Ishikawa Nobuo
Published: July 2006

Utilizing the reactivity of hexafluoro-1,2-epoxypropane, several new fluorine-containing imidazole derivatives were prepared. The reactions involve 2-mercaptobenzimidazole, 2-mercapto-4,5-diphenylimidazole, 2-imidazolidinethione, and 2-aminobenzamide.
The Nucleophilic Substitution Reaction of 1-Halogeno-2-methylsulfonylphenazine 5-Oxides
Authors: Tada Masao
Published: July 2006

The halogen atom in 1-halogeno-2-methylsulfonylphenazine 5-oxide is reactive toward the anionoid reagents through the activating effects of both the sulfone group and the N-oxide group. By the nucleophilic substitutions, some 1-substituted 2-methylsulfonylphenazine derivatives have been prepared in high yields.
The Bimolecular Reduction of Acridine and 9-Substituted Acridines by Sodium 1-Benzyl-1,4-dihydronicotinamide-4-sulfinate
Authors: Inoue Hiroo , Sonoda Ichiro , Inoguchi Nobuaki , Imoto Eiji
Published: July 2006

Sodium 1-benzyl-1,4-dihydronicotinamide-4-sulfinate is found to undergo the bimolecular reduction of acridine or 9-substituted acridines to the corresponding 9,9′-biacridans.
Structures of Copper(II) Complexes Which Deposit Copper in Chemical Copper-plating Bath
Authors: Ohno Seigo
Published: July 2006

The deposition of copper from alkaline solutions containing various copper(II) complexes and formaldehyde was studied. It was found that one-to-one copper(II) complexes of hepta-, hexa-, and quadridentate ligands deposit copper on reduced platinum by means of autocatalytic reduction, and that, under particular conditions, copper(I) oxide is deposited on oxidized platinum from the solutions containing quadridentate ligands.
Correlation of Solvation Free Energy of Electron with Empirical Parameters of Solvents. A Criterion for Electrophilic Effects of Solvents
Authors: Imai Hideo , Yamashita Kazuo
Published: July 2006

The solvation free energy of electrons in N,N-dimethylformamide, methanol, and water was estimated by means of electron photoemission into solution, and the data were compared with empirical parameters such as thermodynamic quantities, structural and kinetic parameters of solvents. It was confirmed that the interaction of an electron with solvent molecules is purely electrostatic and that the solvation free energy can be used as a tentative criterion of electrophilic properties of solvents.
Metal-ion Complexation of Noncyclic Poly(oxyethylene) Derivatives. Complexation in Aprotic Solvent and Isolation of Their Solid Complexes
Authors: Yanagida Shozo , Takahashi Kazutomo , Okahara Mitsuo
Published: July 2006

The interaction of homogeneous polyethylene glycol(PEG) (EOn, n=1–8) with the alkali and magnesium metal cations and the ammonium cation was investigated on the basis of 1H NMR(PMR) downfield shifts in acetone-d6 or in acetonitrile-d3 The specific complexations of EO4 with Mg2+, EO6 with Na+ and Ca2+, and EO7 with K+ were demonstrated by PMR studies, and their solid complexes were isolated. No specific interaction was detected for Rb+ and Cs+ in PMR studies. The magnesium ion interacts strongly with 15-crown-5, 18-crown-6, and PEG in acetone, and the Mg(SCN)2-EO4 and the Mg(SCN)2-above crown ether complexes were isolated. The terminal hydroxyl groups of PEG play an important role in the complexation with Li+ and Mg2+ in acetone. The formation of the 1 : 1 complex with Ca(SCN)2 was observed both for EO6 and for EO7. Strontium and barium thiocyanates formed solid complexes with PEG(EOn, n=2–8) and with glymes(tri- to octaglyme). Some novel complexes of 12-crown-4 and 15-crown-5 with NaSCN and Ca(SCN)2 were also isolated . The mechanism of metal-ion complexation of poly(oxyethylene) derivatives is discussed in terms of the coordination geometry.
Environment Effect on the Symmetry of Yang’s Biradical
Authors: Mukai Kazuo
Published: July 2006

The ESR spectrum of Yang’s biradical, which has a structural three-fold symmetry and degenerate, partially filled levels, has been measured in several solvents at 77 K. The results of the analyses of the ESR spectra have shown that Yang’s biradical must lack a three-fold symmetry in frozen solutions. The notable solvent effects observed for the zero-field splitting parameters (D and E) suggest that the asymmetric environment due to frozensolvent molecules contributes to the molecular distortion found for Yang’s biradical.
Monolayer Properties of Mixtures of Poly(octadecyl methacrylate) and Poly(butyl methacrylate) and Their Corresponding Copolymers
Authors: Yoshikawa Satoshi , Ueno Minoru , Meguro Kenjiro
Published: July 2006

The monolayer properties of mixtures of poly(octadecyl methacrylate) and poly(butyl methacrylate) have been compared with those of their corresponding copolymers of octadecyl methacrylate and butyl methacrylate, using the measurements of their surface pressure-area isotherms at the air/water interface at 20 °C. The results showed that the isotherms of the mixed monolayers had three break points, and the surface pressures of the lower two break points agreed with those of poly(butyl methacrylate). This suggests that at lower surface pressures, the mixtures of the two homopolymers are compatible in a bidimensional state when each phase contains a small amount of the other homopolymer, and otherwise these are incompatible, while at higher surface pressures, up to 70 segment mol% of poly(octadecyl methacrylate) they are incompatible and above 80%, they are compatible. The copolymers showed characteristic isotherms different from those of the mixtures. The properties of the copolymers in the bidimensional state are affected by variations in the vitrified, liquid, or crystalline states with an increase in the mean lengths of the side chains in the three-dimensional state.
The Study of Solutions of Alkali Halides in Acetone by Means of Vapor-pressure Osmometry and Conductometry
Authors: Lee Ha Chung , Miyahara Yutaka
Published: July 2006

Vapor-pressure depressions and electric conductivities at 40.3 °C have been measured for LiCl, LiBr, NaI, KI, and RbI in acetone. The greatest care has been taken to minimize the contact of salts and their solutions with air. In order to account for the data of vapor-pressure osmometry (VPO) for lithium salts in acetone, the dissociation-association equilibria of the salts, MX, expressed as

M++X−\ightleftharpoonsMX\ightleftharpoons1⁄2(MX)2

are proposed. The analysis of the conductance data of LiCl and LiBr, without considering the dimerization of the salts, leads to irrationally large values of the ionic association constants. For LiCl, NaI, and KI, VPO and conductometry give similar values of the dissociation constants, while for LiBr and RbI the agreement is not so satisfactory, though still within a factor of ten.
Crystal Structures of Dichlorobis(azocyclohexane)palladium(II) and Dichlorobis(azoisopropane)palladium(II)
Authors: Yamane Takashi , Ashida Tamaichi , Suzuki Hiroharu , Itoh Kenji , Ismi Yoshio
Published: July 2006

The structures of dichlorobis(azocyclohexane)Pd(II) and dichlorobis(azoisopropane)Pd(II) have been determined. The crystallographic data are: dichlorobis(azocyclohexane)Pd(II), Im3, a=16.538(2)Å, Z=6, R=8.9% for 667 reflections; dichlorobis(azoisopropane)Pd(II), Pbca, a=7.461(1), b=17.096(1), c=14.784(1)Å, Z=4, R=6.8% for 1451 reflections. In dichlorobis(azocyclohexane)Pd(II), a disorder occurs at the azo group, and the coordination mode of the ligand is not clear. The structure of dichlorobis(azoisopropane)Pd(II) agrees with that of dichlorobis(azobenzene)Pd(II).
The Gas Chromatographic Analysis of Bis(chloromethyl) Ether in Air
Authors: Baba Yoshio , Tanaka Toshiyuki
Published: July 2006

Bis(chloromethyl) ether was converted into bis(ethylthiomethyl) ether by a reaction with sodium ethanethiolate in a hexane solution; the latter sulfur-containing compound was then analyzed by means of a gas chromatograph equipped with a flame photometric detector.
The Micellar Acceleration of the Reduction of Nitroblue Tetrazolium by Superoxide Anion Radicals during the Autoxidation of Polyphenols
Authors: Takabe Teruhiro , Miyakawa Masako , Nikai Sueki
Published: July 2006

The rates of the reduction of Nitroblue Tetrazolium by O2− during the autoxidation of pyrogallol, epinephrine, and catechol were increased 110, 55, and 37-fold respectively in the presence of hexadecyltrimethylammonium bromide. A nonionic micelle of polyoxyethylene dodecyl ether also accelerated these reactions. The microenvironment effects on the electron-transfer from O2− to Nitroblue Tetrazolium were discussed.
Mixed Ligand Complexes Derived from the Reactions of Diaquabis-(3-hydroxy-2-methyl-4-pyronato)-cobalt(II), -nickel(II), and -zinc(II) with Pyridine and 4-Substituted Pyridines
Authors: Morita Hideyoshi , Shimomura Shigeru , Kawagughi Shinichi
Published: July 2006

The pyridine(py), 4-methylpyridine(4-Me-py) and 4-cyanopyridine(4-CN-py) adducts of bis(3-hydroxy-2-methyl-4-pyronato) complexes (ML2) of cobalt(II), nickel(II), and zinc(II) have been synthesized: CoL2(py)n (where n=2 or 3), NiL2(py)3, ZnL2(py), ML2(4-Me-py)2 (where M=Co(II), Ni(II), and Zn(II)), ML2(4-CN-py) (where M=Co(II) and Zn(II)), and NiL2(4-CN-py)2. Based on the magnetic, spectral, and thermogravimetric data, three of these complexes, ZnL2(py) and ML2(4-CN-py) (where M=Co(II) and Zn(II)), are presumed to have a five-coordinate structure, while the other complexes are presumed to be octahedral. In the case of the 4-cyanopyridine complexes, the infrared spectra show that the pyridine-ring nitrogen is linked to the metal ion and that the nitrogen atom of the nitrile group is not coordinated.
The Computer-assisted Characterization of Terpenes and Related Compounds by the Use of Combined Spectrometric Data
Authors: Sasaki Shin-ichi , Abe Hidetsugu , Saito Keiji , Ishida Yoshiaki
Published: July 2006

Basic research to prepare a combined retrieval system based on three different sets of spectrometric data, infrared, mass, and 1H NMR, for terpenes and related compounds is described. The system may be used either for searching all three types of spectra, for two, or for one only. The results of 112 test searches are presented. The combined method is proved to be a good tool for the identification of such compounds, especially those in a structurally close relationship.
The Partition Mechanism of Thenoylacetone and Thenoyltrifluoroacetone in Water/Alcohol Systems
Authors: Suzuki Nobuo , Shibuya Hidenori , Watarai Hitoshi
Published: July 2006

The apparent partition coefficients of thenoylacetone (TA) in ten alcohol/water systems and the enol fractions of TA in both phases were determined. Comparing the results with those of thenoyltrifluoroacetone (TTA), the substituent effect of methyl and trifluoromethyl groups on the partition behavior of the β-diketones in the alcoholic partition systems was examined. The experimental results showed that the apparent partition coefficient of TA is larger than that of TTA, while the partition coefficient of the enol form of TA is smaller than that of TTA. This was related to the differences in the partitioning species of TA and TTA; that is, TA is in keto and enol forms, while TTA is in enol, hydrate, and hemiacetal forms. The partition coefficient of each species was discussed in terms of the solubility parameter of alcohol.
Chemical Vapor Deposition of Titanium Disulfide
Authors: Motojima Seiji , Itoh Kazuaki , Takahashi Yasutaka , Sugiyama Kohzo
Published: July 2006

Chemical vapor deposition of TiS2 was examined. TiS2 was deposited on a quartz substrate above 300 °C from a gas mixture of TiCl4, H2S, and Ar. Maximum deposition rate was attained at 700–800 °C for a 0.7 gas flow ratio H2S/(TiCl4+H2S) irrespective of temperature. Crystal morphology and composition were strongly affected by temperature and gas compositions. Well-formed TiS2 crystals were grown either at 600 °C or from a gas mixture of low flow ratio 0.2 of H2S/(TiCl4+H2S). Single phase of TiS2 was deposited in the temperature range 400–850 °C.
Asymmetric Induction on the Reaction of Prochiral Olefins with Chloro-l-aminocarboxylato-η2-ethyleneplatinum(II)
Authors: Terai Yoshiro , Kido Hiroaki , Kashiwabara Kazuo , Saito Kazuo
Published: July 2006

Addition of a large excess of trans-2-butene (tbn) or 2-methyl-2-butene (mbn) to an acetone solution of cis- or trans(N, ethylene)[PtCl(l-am)(C2H4)] (l-am, 9 kinds of l-aminocarboxylate) gave first increase and then gradual decrease in CD strength in the region \simeq26500 cm−1. The kinetic optical yield amounted to 53% whereas that at the equilibrated state was much less (up to 27% for cis(N, olefin) complexes and 6 to 12% for trans complexes), trans-2-Butene gives larger yields than mbn. Kinetic analysis of the growth and decay curve of the CD strength disclosed that the first fast increase in CD reflects the greater rate of substitution of the prochiral olefins for ethylene in S-configuration than that in R-configuration. The second step seems to involve the exchange of coordinated tbn or mbn catalyzed by ethylene which was made free in the first step. The mechanism of asymmetric induction has been discussed from both steric and electronic viewpoints. Asymmetry of the coordinated nitrogen seems to give a dominating effect.
Syntheses of Heliparvifoline and O-Demethylpteleine
Authors: Sekiba Tetsuya
Published: July 2006

2,3-Dihydroheliparvifoline (Va) was obtained from 4-methoxy-3-benzyloxyaniline by condensation with diethyl (2-benzyloxyethyl)-malonate, and by subsequent methylation, debenzylation, and then cyclodehydration. Benzyl ether of Va was dehydrogenated and then treated with hydrochloric acid to give heliparvifoline.
A New Synthesis of l-4-Amino-2-hydroxybutyric Acid. Carboxyl-Assisted Nitrile Synthesis from Primary Amides
Authors: Yoneta Toshio , Shibahara Seiji , Fukatsu Shunzo , Seki Shigeo
Published: July 2006

l-2-Hydroxysuccinamic acid prepared from l-asparagine was dehydrated with acetic anhydride in pyridine, affording the respective ω-cyano acid, which, on catalytic hydrogenation, gave the title compound. Similarly, the amide groups of some other β- and γ-amic acids were dehydrated to give the respective cyano acids in good yields.
The Crystal and Molecular Structure of Dichlorobis(2-pyridinethiolato)tin(IV)
Authors: Masaki Mitsuo , Matsunami Satoshi , Ueda Hideo
Published: July 2006

The crystal and molecular structures of dichlorobis(2-pyridinethiolato)tin(IV) have been determined by X-ray analysis. The crystal belongs to the triclinic system: a=8.340(8), b=12.456(7), c=7.178(3) Å, α=86.46(4), β=111.06(5), γ=99.18(6)°, space group P\bar1 with Z=2. The structure was determined by the heavy atom method and refined by the block-diagonal least-squares method (R=0.058). The complex is a distorted octahedral complex in which 2-pyridinethiolato ligands act as bidentate ligands, two four-membered (Sn, S, C, and N) chelate rings being present. Two Sn–Cl bonds are cis, two Sn–N bonds are cis, and two Sn–S bonds are trans configuration.
Radiation Chemical Reactions in Carbon Dioxide–Propane System. II. Reoxidation of Carbon Monoxide at Low Propane Concentration
Authors: Ikezoe Yasumasa , Sato Shoichi
Published: July 2006

In the γ-radiolysis of carbon dioxide, the back reaction or reoxidation of carbon monoxide, proceeds at a moderate rate with propane concentration less than 0.5%, reducing the apparent G(CO) value. Concerning the total pressure and dose rate dependence of the G(CO) value with such small propane addition, it was found that the back reaction was accelerated by raising the total pressure and by lowering the dose rate. The following reactions of clustered negative ions are considered to explain the pressure and dose rate effects:

X−+CO→CO2+Y−+Z1,

X−+C3H8→Y−+Z2,

X−+X+→mCO2+Z3,

where X− stands for a clustered negative ion.
The Effect of Surfactants and β-Cyclodextrin on the Photooxidation of Stable Carbanions
Authors: Yamada Kazutoshi , Shigehiro Kiyoshi , Tomizawa Tetsuo , Iida Hirotada
Published: July 2006

The micellar effect on the photochemistry of α-(4-hydroxyimino-2,5-cyclohexa-dienylidene)-α-phenylacetonitrile and its derivatives has been studied. 4-Nitrobenzophenone derivatives were obtained by the irradiation of ethanolic alkaline aqueous solutions of the oximes. 4-Nitrosobenzophenone derivatives formed as an intermediate were thermally oxidized to give the corresponding nitro compounds. The reaction was found to be the photochemical oxidation by singlet oxygen. The addition of an anionic surfactant (sodium dodecyl sulfate) and a nonionic surfactant (Tween #80) to the reaction solution scarcely changed the pKa values of oximes, whereas the addition of a cationic surfactant such as hexadodecyltrimethylammonium bromide (HTAB) caused a considerable decrease. This indicates that HTAB promotes the formation of a stable carbanion. The presence of HTAB enhanced the rate of photooxidation by a factor of 102. The catalytic effect becomes maximum at the pH value of the reaction solution near the pKa measured in the presence of HTAB or β-CDX.
Peptides. VII. Some Sulfonates of Strongly Acidic N-Hydroxy Compounds as Novel Coupling Reagents
Authors: Itoh Masumi , Nojima Hiroshi , Notani Jiyoji , Hagiwara Daijiro , Takai Kuniaki
Published: July 2006

Sulfonates of strongly acidic N-hydroxy compounds such as 6-chloro-1-(p-chlorophenylsulfonyloxy)benzotriazole have been found to be excellent coupling reagents for amide bond formation. Amides can be prepared through either an active ester or a mixed anhydride according to the chosen procedure. Several active esters and protected di- and tripeptides prepared are listed in the Tables. Racemization, possible side reactions, and reaction pathways of the amide bond formation have also been discussed.
The Reaction of Dibenzylselenonium Ylides with Various Acids
Authors: Tamagaki Seizo , Tamura Katsuyuki , Kozuka Seizi
Published: July 2006

Dibenzylselenonium cyano(methoxycarbonyl)methylide and dibenzylselenonium dicyanomethylide react readily with strong acids at room temperature, giving 1,3-diselena compounds and active methylene compounds.
Hydrogenation and Hydrogenolysis. XVI. The Reactions of Two Isomeric Enol Ethers of 3-Methylcyclohexanone over Platinum Group Metals
Authors: Nishimura Shigeo , Kagawa Kunihiro , Sato Nobuo
Published: July 2006

The two isomeric enol ethers of 3-methylcyclohexanone, 1-ethoxy-3-methyl-, and 1-ethoxy-5-methylcyclohexenes (5 and 6), have been hydrogenated in ethanol with six platinum group metals as catalysts. Palladium, rhodium, and platinum efficiently catalyzed the addition of ethanol to the enol ethers to give the corresponding acetal, while iridium and ruthenium catalyzed it only slightly. Osmium was moderately active for the acetal formation. Extensive isomerization between 5 and 6 occurred over all catalysts. In addition, isomerization to an allyl ether, 3-ethoxy-1-methylcyclohexene (9), was observed with 5 over the metals other than palladium. Hydrogenation of 5 and 6 with palladium gave the trans-ether predominantly. With the other metals, the cis-ether was formed in large excess from 5 and the trans-ether in slight excess from 6 at the initial stage of hydrogenation. Hydrogenolysis of the ethoxyl group occurred extensively over platinum but only slightly with palladium and ruthenium. These results are compared with those obtained with the corresponding dimethylcyclohexenes and allyl ether 9.
Preparation and Diels-Alder Reactions of 3-Substituted 3-Sulfolenes
Authors: Inomata Katsuhiko , Kinoshita Hideki , Takemoto Hisayo , Murata Yasue , Kotake Hiroshi
Published: July 2006

It was found that 3-(p-tolylsulfonyl)- and 3-(p-tolylsulfinyl)-3-sulfolenes prepared from 3-sulfolene react with various dienophiles to give the corresponding Diels-Alder cycloadducts in good yields, and that only the “para” substituted cycloadducts are obtained with monofunctionalized (CHO, COCH3, CO2CH3, CN, and C6H5) ethylenes and methyl 2-methylpropenoate, respectively.
Dehydroannulenes. IX. Effects of Substituents on the 1H NMR Spectra of Tetrakisdehydro[18]- and Bisdehydro[14]annulenes
Authors: Akiyama Shuzo , Iyoda Masahiko , Yoshitsugu Kiyoshi , Fukuoka Masatoshi , Nakagawa Masazumi
Published: July 2006

In order to obtain information on the cause of low field shift of 1H NMR signals of ‘acetylene-cumulene’-dehydroannulenes on introduction of substituents, the syntheses of 1,8-bisdehydro[14]- and 6,8,15,17-tetrakisdehydro[18]annulenes bearing p-substituted phenyl group(s) have been performed. The examination of their 1H NMR spectra indicates that the low field shift of NMR signals can be regarded as a superposition of three effects, i.e., 1) decrease of ring current in annulene nucleus by perturbation of substituent group(s), 2) Deshielding effect of ring current in aryl substituent(s) exerted on annulene protons, and 3) Electronic effect of p-substituent in phenyl group(s) transmitted to annulene ring.
Fluorescence of the Proton Transferred Excited Species between 4-Amino-2-methyl-5H-[1]benzopyrano[3,4-c]pyridin-5-one and Acetic Acid. Time-Resolved Fluorescence Spectra and Solvent Effects
Authors: Fujimoto Akira , Hirose Hiroshi
Published: July 2006

The nanosecond time-resolved spectra and apparent lifetime for the fluorescence of the proton transferred excited species (tautomer) between 4-amino-2-methyl-5H-[1]benzopyrano[3,4-c]pyridin-5-one (BPP) and acetic acid have been measured in isooctane (2,2,4-trimethylpentane) at room temperature. It has been established that the rising time of the tautomer fluorescence was ca. 15 ns and the time required for the excited hydrogen-bonded species-tautomer equilibrium was ca. 40 ns. Solvent effects upon the fluorescence characteristics of the tautomer have also been investigated.
Surface Nonstoichiometry and Isoelectric Point of Manganese Oxide
Authors: Morimoto Tetsuo , Nakahata Hidetoshi , Kittaka Shigeharu
Published: July 2006

The isoelectric point and the nonstoichiometric composition of the surface layer were measured for manganese oxide samples treated in vacuo or in air at elevated temperatures. It was found that the surface composition of most samples tested was oxygen-deficient with reference to the bulk composition, and that the IEP was determined by the bulk structure rather than the surface composition. This was ascribed to the fact that the surface is heterogeneous and the dissolution of the solid will take place preferentially at surfaces which involve defect structures or Mn(II) ions.
The Chemistry of Isocyanic Acid and Its Derivatives. Part V. The Oxidative Coupling of Ethyl Carbamate and Urea with Cyclohexene, Tetrahydrofuran, and Cyclooctadiene Effected by Palladium(II) Chloride
Authors: Ozaki Shoichiro , Tamaki Akihiro
Published: July 2006

The reaction of ethyl carbamate with cyclohexene promoted by PdCl2 gave ethyl 1-cyclohexenylcarbamate. The reaction of ethyl carbamate and tetrahydrofuran gave ethyl 2-tetrahydrofurylcarbamate. Ethyl carbamate and 1,5-cyclooctadiene–PdCl2 complex (4) reacted to give ethyl 4-cyclooctenylcarbamate. The reaction of urea and 4 afforded cyclooctylurea and 4-cyclooctenylurea.
Synthesis of Chromenochlalcone Glucosides
Authors: Yamada Shigetoshi , Ono Futara , Katagiri Takao , Tanaka Juntaro
Published: July 2006

Some chromenochalcone glucosides were synthesized in 24–62% yields from 6-acetyl-5,8-dihydroxy-2,2-dimethylchromene and various (β-glucosyloxy)benzaldehydes.
A Synthesis of (±)-epi-Seychellene
Authors: Yamada Kiyoyuki , Kyotani Yoshinori , Manabe Shunichi , Suzuki Masaaki
Published: July 2006

Starting from a mixture of two diastereomeric ketols, (±)-seychellene and (±)-epi-seychellene were synthesized in six steps.
A Shock Tube Study on the Pyrolysis of Acetylene in the Presence of Nitrogen Oxide
Authors: Ogura Hiroo
Published: July 2006

The pyrolysis of acetylene in the presence of nitrogen oxide has been investigated by use of a single-pulse shock tube in the temperature range 1100–1650 K. The hydrocarbons produced in the presence of nitrogen oxide were quite the same as those obtained from the pyrolysis of acetylene by itself. The yield-temperature plots of 1-buten-3-yne showed that at temperatures below 1350 K the formation rate of 1-buten-3-yne is reduced by the addition of nitrogen oxide. The retarding effect of nitrogen oxide on the 1-buten-3-yne formation was interpreted in terms of the reactions of nitrogen oxide with 1-ethynylvinyl and 2-ethynylvinyl radicals to yield pro-pynenitrile and hydrogen cyanide, respectively. An illustrative radical chain mechanism was presented for the pyrolysis of acetylene in line with the experimental results obtained from the pyrolysis inhibited by nitrogen oxide. The radical chain is initiated by the bimolecular reaction of acetylene, viz. 2C2H2→C4H3+H, ethynyl and 2-ethynylvinyl radicals being the chain carriers, where C4H3 is 1-ethynylvinyl radical.
The Chromium(VI) Oxide Oxidation of Epimeric 1,2,3,4-Tetrahydro-1-naphthols
Authors: Hanaya Kaoru , Awano Sachio , Kudo Hideaki
Published: July 2006

The rates of the chromium(VI) oxide oxidation of 2- and 3-substituted 1-tetralols(1,2,3,4-tetrahydro-1-naphthols) have been determined. In the 3-substituted compounds, the rates of cis-isomers(eq’-OH) are markedly larger than those of trans-isomers(ax’-OH). On the other hand, in the case of 2-substituted compounds, the rates of the cis-isomers(ax’-OH) and trans-homers (eq’-OH) are almost equal.
The Reaction of Hydrogen Chloride with Nitrogen Oxide in Shock Waves
Authors: Higashihara Tetsuo , Saito Ko , Murakami Ichiro
Published: July 2006

The reaction of hydrogen chloride with nitrogen oxide in the temperature range 2670–3850 K and in the pressure range 2.5–3.5 atm has been studied behind reflected shock waves by monitoring the IR emission of HCl. When nitrogen oxide was added to the HCl–Ar system, the rate of HCl dissociation was found to be accelerated. For the early stage of reaction, the rate equation obtained was –d[HCl]/dt=1011.7exp (−33 kcal/RT)[HCl]1.3[NO]0.5 mol cm−3 s−1. As the initiation step, Reaction 1 was found to be more important than Reaction 2 under these experimental conditions:

HCl+NO→HNO+Cl, (1)

HCl+Ar→H+Cl+Ar. (2)

The rate constant of Reaction 1 was determined to be k1=1013.2exp (−50.2 kcal/RT) cm3 mol−1 s−1.
The Reaction of Hydrogen Bromide with Nitrogen Oxide in Shock Waves
Authors: Higashihara Tetsuo , Saito Ko , Murakami Ichiro
Published: July 2006

The reaction of hydrogen bromide with nitrogen oxide in the temperature range 2000–3300 K and in the pressure range 0.7–3.8 atm has been studied behind reflected shock waves by monitoring the IR emission of HBr. For the early stage of the reaction, the rate equation obtained was −d[HBr]/dt=koverall[HBr]1±0.3[NO]0.7±0.2[Ar]0±0.1, where koverall=1010.4±0.2exp{−(23.2±3.0) kcal/RT} cm2.1 mol−0.7 s−1. As the initiation step, Reaction 1 was found to be more important than Reaction 2:

HBr+NO→HNO+Br, (1)

HBr+Ar→H+Br+Ar. (2)

The rate constant of Reaction 1 was determined to be k1=1012.8exp(−30kca⁄RT) cm3 mol−1 s−1.
Oxidation of Propylene Adsorbed on Metal Oxides. Oxygen Species in Catalytic Oxidation
Authors: Kubokawa Yutaka , Ono Takehiko
Published: July 2006

Adsorption of ethylene and propylene has been investigated volumetrically with various oxide catalysts. From the results together with those of oxidation of propylene adsorbed on oxides, it is concluded that the difference between the characteristics of oxidation of propylene adsorbed on the oxide catalysts for complete or selective oxidation is attributable to the difference in the oxygen species responsible for oxidation rather than that in the adsorbed state of propylene. A comparison of characteristics of the oxidation of adsorbed propylene in the presence of gaseous oxygen and in a vacuum suggests that on the catalysts for complete oxidation, adsorbed oxygen plays a significant role in the oxidation because of its higher activity as compared to that of lattice oxygen.
An Analysis of the Through-bond Interaction Using the Localized Molecular Orbitals. I. Interactions between Lone-pair Orbitals in Azines: Pyridazine, Pyrimidine, and Pyrazine
Authors: Ohsaku Masaru , Imamura Akira , Hirao Kimihiko
Published: July 2006

The CNDO/2 and INDO calculations were performed on three azines: pyridazine, pyrimidine, and pyrazine. In order to check the validity of the lone-pair orbital energies, the calculated orbital energies were compared with those obtained by ab initio calculations. These molecules have two lone-pairs, which can be transformed into symmetric and antisymmetric combinations. In pyridazine and pyrimidine, the symmetric one is lower than the antisymmetric one in energy, while in pyrazine the reverse is true. These results were subjected to an analysis from the standpoint of the through-bond interaction. That is, we transformed the canonical molecular orbitals obtained by the CNDO/2 method into localized molecular orbitals. By the use of the localized molecular orbitals thus obtained, the variation in the lone-pair orbital energies of these molecules was estimated in terms of the through-bond (and/or the through space) interaction according to a method which selectively considered the particular interaction between the specified localized molecular orbitals in a molecule. As a result of this analysis, it was found that the relative order of the lone-pair orbital energies was determined by the different types of interactions from molecule to molecule, and the energy variation in the lone-pair orbitals was elucidated in terms of the specified through-bond and through-space interactions.
Electronic Absorption and Fluorescence Spectra of [2.2]Anthracenophanes
Authors: Morita Masaharu , Kishi Tohru , Tanaka Masashi , Tanaka Jiro , Ferguson James , Sakata Yoshiteru , Misumi Soichi , Hayashi Toyoharu , Mataga Noboru
Published: July 2006

The absorption and the fluorescence spectra of four [2.2]anthracenophanes were investigated at low temperatures. A theoretical calculation of the energy levels was performed by including the charge resonance and the exciton type interactions. The fluorescence excitation polarization spectra were recorded for all absorption bands at low temperatures, the directions of the transition moment of the excimer type emission bands being estimated by the p-values and the established transition directions of anthracene chromophores. The assignments of the absorption bands are presented based on these results.
Electrical Properties of Langmuir Films of Fatty Acid Salts and Carotenoic Acid
Authors: Yamamoto Naoto , Ohnishi Toshihiro , Hatakeyama Masahiro , Tsubomura Hiroshi
Published: July 2006

Electric conductivities have been studied for Langmuir molecular layers of barium salt of fatty acids and for the layers of barium arachidate mixed with all-trans-β-apo-8′-carotenoic acid. These results have been interpreted based on an electron tunneling model taking account of the mirror image force. The conduction levels of the layers have thereby been estimated to be 1.00 eV for barium stearate, 1.31 eV for barium arachidate and 1.45 eV for barium behenate below vacuum level. The conduction level of the carotenoic acid has been derived to be 1.9 eV from these results. The structure of these layers has been discussed from the above mentioned experimental results, together with those on surface pressure, absorption spectrum and electric capacitance.
The Effect of High Density Excitation on the Phosphorescence Spectra and Decay Times of Several Crystalline Uranyl(VI) Salts
Authors: Kobayashi Takayoshi
Published: July 2006

The effect of high density excitation on the phosphorescence spectra and their decay curves of crystalline uranyl(VI)nitrate hexahydrate, uranyl(VI)acetate dihydrate, and zinc uranyl(VI)acetate heptahydrate was studied using a nitrogen laser as the exciting light source. The relative emission intensity of the spectra in the shorter wavelengths decreased and the vibrational structure became broader at higher density excitations; these changes were attributed to the saturation in excitation and to the temperature increase in the irradiated volume of the sample crystal caused by the heat released in the radiationless decay process. A decrease in the decay time was also observed at high density excitations; this shortening was attributed to bimolecular quenching of triplet excitons in the crystal. The rate constant for this process in crystalline uranyl nitrate hexahydrate was measured at several temperatures between 77 and 295K; it was 2.6×10−13 cm3 s−1 at 295K for example. From this rate constant the hopping rate for a triplet exciton in crystalline uranyl nitrate hexahydrate was obtained: 4.3×108 cm3 s−1 at 295K. The activation energy for the exciton migration was found to be 320 cm−1.
Kinetic Studies on the Stability Enhancement of Mixed Ligand Copper(II) Complexs with 2,2′-Bipyridyl and Acetylacetonate
Authors: Munakata Megumu , Yamada Katsumi
Published: July 2006

The rate constants for the formation and dissociation of the binary Cu2+-acetylacetonate(acac−) complex and the ternary 2,2′-bipyridyl(bpy)-Cu2+-acac− complex have been determined by the temperature-jump method. For the reactions Cu2++acac−\oversetk1b\undersetk-1b\ightleftharpoonsCu(acac)+, Cu(acac)++acac−\oversetk2b\undersetk-2b\ightleftharpoonsCu(acac)2, and Cu(bpy)2++acac−\oversetk1t\undersetk-1t\ightleftharpoonsCu-(bpy)(acac)+, the rate constants are k1b=9.0×108 M−1 s−1, k-1b=3.2 s−1, k2b=7.0×107 M−1 s−1, k-2b=13 s−1, k1t=1.1×109 M−1 s−1 and k-1t=1.9 s−1. A comparison of the reactions shows that the forward rate for the Cu(bpy)-(acac)+ formation is larger than that for Cu(acac)+ and, subsequently, the rate of the complex formation between Cu(bpy)2+ and acac− is enhanced by the coordinating bpy. On the other hand, the reverse rate for the ternary complexation reaction is smaller than for the binary. This illustrates that the dissociation of acac− of Cu(bpy)-(acac)+ becomes more difficult owing to the coordination of the bpy. The above two effects of the bpy may be driving forces producing high stability, i.e., a positive value of ΔlogK\left(K=\frac[Cu(bpy)[L][Cu(bpy)][L]\ight) for the ternary copper(II) complexes with bpy and other ligands containing O as donor atoms.
Reaction Process between Iron(II) Chloride and Oxygen
Authors: Saeki Yuzo , Matsuzaki Ryoko , Fujiwara Seiki
Published: July 2006

The product formed by heating FeCl2 in an oxygen stream has been examined in detail. The reaction processes of gaseous FeCl3 and FeOCl, formed during the reaction between FeCl2 and oxygen, with oxygen were also examined. The reaction process between FeCl2 and oxygen can be represented as follows: FeCl2 reacts with oxygen above about 250 °C to form FeOCl and gaseous FeCl3, 2FeCl2(s)+1/2O2(g)→FeOCl(s)+1/2Fe2Cl6(g). Subsequently, the resulting FeOCl reacts with oxygen to form α-Fe2O3 and chlorine, 2FeOCl(s)+1/2O2(g)→Fe2O3(s)+Cl2(g). Above about 320 °C, the decomposition of the FeOCl to α-Fe2O3 and gaseous FeCl3, 3FeOCl(s)→Fe2O3(s)+1/2Fe2Cl6(g), also occurs. Above about 370 °C, the reaction between gaseous FeCl3 formed and oxygen to form η-Fe2O3 and chlorine, Fe2Cl6(g)+3/2O2(g)→Fe2O3(s)+3Cl2(g), occurs in addition to the above reactions.
Reaction of Organic Tin(II) Compound with Phenyl Isothiocyanate and Carbon Disulfide
Authors: Wakeshima Ikuko , Saitoh Yoshihiro , Kijima Ichiro
Published: July 2006

Reaction of organic tin(II) compounds, Sn(OR)2[R=C2H5, CH2CH2N(CH3)2, C6H5, o-CH3C6H4], with phenyl isothiocyanate and carbon disulfide have been investigated. The reaction of di(ethoxo)tin(II) with phenyl isothiocyanate in benzene at room temperature gave the corresponding addition product. The reaction at 80–81 °C however gave diethyl N-phenylcarbonimidate. Phenyl isothiocyanate reacted exothermically with bis[2-(dimethylamino)ethoxo]tin(II) to yield the 1 : 1 addition product. In the reaction with bis(2-methylphenoxo)tin(II), a compound containing one molecule of phenyl isothiocyanate per two molecules of the tin(II) compound was isolated, but the reaction with di(phenoxo)tin(II) did not occur. Di(ethoxo)tin(II) reacted with carbon disulfide to give diethyl thiocarbonate, diethyl carbonate, and tetraethyl orthocarbonate. Bis(o-methylphenoxo)tin(II) and di(phenoxo)tin(II) however did not react with carbon disulfide.
The Chlorination of Norbornene and Cyclooctadienes with Sulfuryl Chloride and Phosphorus(V) Chloride. Ionic vs. Radical Chlorination with Each Reagent
Authors: Uemura Sakae , Okazaki Hajime , Onoe Akira , Okano Masaya
Published: July 2006

The chlorination of norbornene and cyclooctadienes with sulfuryl chloride and phosphorus(V) chloride has been investigated mainly in carbon tetrachloride under various conditions. From the studies of the product distributions and the effect of radical scavengers, the following facts have been revealed for the first time in olefin chlorination: chlorination with sulfuryl chloride proceeds through an ionic pathway at room temperature or in the presence of silica gel and that with phosphorus(V) chloride through a radical pathway at elevated temperature, and an ionic chlorination with phosphorus(V) chloride in nonpolar solvents does not seem to involve C–P bond formation through the reaction.
Synthesis of (±)-Tetrahydroanhydroaucubigenone and (±)-Tetrahydroanhydroaucubigenin
Authors: Obara Heitaro , Kimura Hiroshi , Suzuki Masanobu , Onodera Jun-ichi
Published: July 2006

The racemate of tetrahydroanhydroaucubigenone (3), one of the related compounds of aucubin, was synthesized by the photoirradiation of 6-[2-(nitrosooxy)ethyl]-3-oxabicyclo[3.3.0]octan-7-one. (±)-Tctrahydroanhydroaucubigenin was also obtained by reduction of (±)-3 with sodium in moist ether.
Synthesis of 2′,3′,4,4′,6′-Pentahydroxychalcone, an Aglycone of Carthamin, and Its Isomerization into 4′,5,6,7- and 4′,5,7,8-Tetrahydroxyflavanone, Carthamidin and Isocarthamidin
Authors: Obara Heitaro , Onodera Jun-ichi , Kurihara Yuji , Yamamoto Fumitada
Published: July 2006

2′,3′,4,4′,6′-Pentahydroxychalcone (4), an aglycone of carthamin, was synthesized by the demethoxymethylation of 2′,3′,4,4′,6′-pentakis(methoxymethoxy)chalcone prepared by the condensation of 2,3,4,6-tetrakis(methoxymethoxy)acetophenone with p-methoxymethoxybenzaldehyde. 4 was converted into 4′,5,6,7- and 4′,5,7,8-tetrahydroxyflavanone (5 and 6) by boiling with methanolic hydrochloric acid. On the basis of the comparisons of the properties of 5 and 6 with those of carthamidin (A) and isocarthamidin (B) derived from natural product, the structures originally assigned for A and B should be reversed.
Optical Spectra of the Picrate Ion in Micellar and Polymer Micellar Systems. Comment on the Solvation of Anions
Authors: Shinkai Seiji , Ide Toyoko , Manabe Osamu
Published: July 2006

The optical spectra of the picrate ion in a micellar solution indicate that slightly below the CMC of CTAB surfactant the anion is relatively free and exists as an ion pair above the CMC. The hydrophobic aggregate of TMAC invariably gives free ion. The polymer micelle of quaternized poly(4-vinylpyridine) results in a tight ion pair.