bluuebunny/crossref_metadata_2025 huggingface dataset:
The Dimerization of 2-Methylpropene Induced by γ-Radiation at High Temperatures and Pressures
Authors: Naito Teruyuki
Published: July 2006

The dimerization of 2-methylpropene by γ-irradiation occurred at a temperature of 300 °C and a 2-methylpropene density of 0.1 g/cm3, giving rise to the formation of 1,1,3-trimethylcyclopentane. The G value of this dimer was 50 at an absorbed dose rate of 4.3×1018 eV/g h and a total absorbed dose of 2.2×1019 eV/g. The G value of this dimer was inversely proportional to about 0.47 the power of the absorbed dose rate and was proportional to the 2-methylpropene density. The formation of this dimer was suppressed by the addition of oxygen or nitrogen monoxide. These facts led to the conclusion that the dimer was formed via chain reactions with the participation of the 2-methylallyl radical.
The Electronic States of (SN)x and (SCH)x Polymers
Authors: Yamabe Tokio , Tanaka Kazuyoshi , Imamura Akira , Kato Hiroshi , Fukui Kenichi
Published: July 2006

One-dimensional (SN)x and its isoelectronic system (SCH)x polymers are treated on the basis of the SCF-tight-binding MO theory. The Pennsylvania structure of (SN)x has been shown energetically favorable comparing the Lyon structure. Judging from the state density at the Fermi level of (SCH)x, it may be expected to be a metallic conductor under some favorable condition.
Thermodynamic Properties and Phase Transitions of Methyltriphenylphosphonium and Methyltriphenylarsonium Bis(7,7,8,8-tetracyanoquinodimethanide)s and Their Solid Solutions
Authors: Kosaki Akio , Sorai Michio , Suga Hiroshi , Seki Syûzô
Published: July 2006

The heat capacities of stable organic free-radical salts [(C6H5)3PCH3]1−x+[(C6H5)3AsCH3]x+(TCNQ)2\ewdot (x=0,0.159, 0.250, 0.449, and 1, and TCNQ=7,7,8,8-tetracyanoquinodimethane) have been measured with an adiabatic calorimeter in the temperature range between 12 and 370 K. The phase transitions are found for the former four cases at 315.65, 325.80, 333.05, and 357.92 K, respectively. The enthalpy and the entropy due to the phase transitions are determined. The transition temperature is raised by diluting the phosphonium salt with the arsonium one. This tendency is quite contrary to that found for usual solid solutions. The magnitude and the composition dependence of the transition entropy indicate that the phase transition of the solid solutions may be attributable to the changes in both the crystal structure and the magnetic spin state at the transition point. A plausible explanation for the present unusual tendency for the composition dependence is presented.
Electrical Properties and Constitution of the Phenothiazine–Iodine and Related Complexes
Authors: Doi Susumu , Inabe Tamotsu , Matsunaga Yoshio
Published: July 2006

The electrical properties of the phenothiazine–iodine complex were examined in detail as a function of the composition. A shoulder in the resistivity-composition isotherm, a decrease in the activation energy for semiconduction by a factor of two, and a change in the sign of the Seebeck coefficient from negative to positive were observed at a composition of two molecules of phenothiazine to five atoms of iodine. These observations and the spectral behavior reported earlier indicate the formation of a complex cation radical salt, (phenothiazine)2+I5−, which exhibits a resistivity of about 800 ohm cm at room temperature. By the incorporation of a half mole of iodine into this salt, the resistivity reaches a minimum of about 20 ohm cm at room temperature. Similar singularities in the resistivity-composition isotherms were observed with the complexes of the benzo[a]-, benzo[c]-, and N-methylderivatives.
Relaxation Studies of the Adsorption-Desorption Equilibrium of Surfactants on the Gas-Liquid Interface. II. Experimental Studies
Authors: Sasaki Minoru , Yasunaga Tatsuya , Tatsumoto Nobuhide
Published: July 2006

The propagation characteristics of the capillary wave were studied in aqueous solutions of sodium dodecyl sulfate, octylamine hydrochloride, and dodecylamine hydrochloride. In most of the solutions, relaxation was observed both in the propagation velocity and the damping coefficient; it could be well interpreted by means of the theory for the propagation characteristics derived in Part I. The obtained relaxation parameters reveal the dynamic behavior of the adsorption-desorption of surfactants on the gas-liquid interface.
Complexes between Nucleotide Base and Amino Acid. III. Crystal Structure of 5-Bromocytosine:Phthaloyl-Dl-glutamic Acid Complex Hemihydrate
Authors: Ohki Minoru , Takenaka Akio , Shimanouchi Hirotaka , Sasada Yoshio
Published: July 2006

5-Bromocytosine and phthaloyl-Dl-glutamic acid co-crystallize from their aqueous solution in space group P\bar1, with dimensions of a=10.578(2), b=19.640 (4), c=9.890 (3) Å, α=88.13 (2), β=107.86 (3), γ=104.26 (1)°. Two molecular complexes and one water molecule are in an asymmetric unit. The structure was solved by the heavy atom method and refined by a block-diagonal least-squares method. The 5-bromocytosine molecule binds with γ-carboxyl group of the amino acid through NH···O and OH···O hydrogen bonds. In spite of largely different molecular environment in the crystal from that of 5-bromocytosine:N-tosyl-l-glutamic acid complex, the mode of interaction between the nucleotide base and the amino acid is the same. Thus, it is suggested that the present geometry is a typical binding mode between cytosine and acidic side group of amino acid.
Studies on Hydroxy Amino Acids. VI. Formation of the Oxazoline Derivatives from N-Acyl-β-hydroxy Amino Acid Peptides
Authors: Nakajima Kiichiro , Kawai Haruki , Takai Michihiro , Okawa Kenji
Published: July 2006

Oxazoline derivatives were mainly obtained from the O-tosyl-N-acyl-β-hydroxy amino acid peptides by β-elimination reaction. Dehydroalanine or hydantoin derivatives were isolated when the urethane type acyl groups were used.
A Facile Synthesis of Anomeric Methyl Dl-Tolyposaminides, Methyl Dl-Forosaminides, and Related Substances
Authors: Kaji Eisuke , Kohno Haruo , Zen Shonosuke
Published: July 2006

The reaction of β-nitro alcohols (2-nitroethanol, 1-nitro-2-propanol, and 1-nitro-2-butanol) with acrylaldehyde in the presence of diethylamine-formic acid gave anomeric mixture of 4-nitro-Dl-pento-, hexo-, and heptopyranoses (5) in reasonable yields. 5 were converted to the corresponding methyl 4-amino-Dl-pento-, hexo-, and heptopyranosides (8) by O-methylation followed by reduction. Anomeric methyl Dl-tolyposaminides and Dl-forosaminides were synthesized in a good yield from anomeric methyl 4-nitro-2,3,4,6-tetradeoxy-Dl-erythro-hexopyranosides (6b1 and 6b2). The configuration of methyl 4-nitro-Dl-hexo-, and heptopyranosides (6b and 6c) and methyl 4-acetamido-Dl-hexo- and heptopyranosides (8b and 8c) was established on the basis of PMR data.
The Synthesis of Benzannelated Annulenes. Tribenzo[a,g,m]-15,17-bisdehydro[18]annulene, and Bis[dibenzo[1,2:9,10]-11,13-bisdehydro[14]annuleno][5,6-a:5′,6′-d]benzene
Authors: Ojima J\={u}ro , Enkaku Michiko , Uwai Chikako
Published: July 2006

The Wittig reaction between o-ethynylcinnamaldehyde (II) and α,α′-bis(triphenylphosphonio)-o-xylene dibromide (III) gave the corresponding acyclic compound (IV and V) in a good yield, while that between o-ethynylbenzaldehyde (VII) and α,α′,α″,α'″-tetrakis(triphenylphosphonio)durene tetrabromide (VIII) similarly afforded an acyclic compound (IX) in a moderate yield. The title compounds, VI and X, were obtained by the oxidative coupling of V (or, IV and V) and IX, respectively. The examination of the NMR spectra indicated that VI and tribenzo-fused, fourteen-membered periphery on the sides of the benzene nucleus of X are atropic.
Reactions of Aromatic Compounds in Molten Salts. I. Dimerization of Aromatic Amines in a Molten Mixture of AlCl3–NaCl–KCl
Authors: Imaizumi Hiroshi , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

Aromatic amines underwent dimerization in a molten salt consisting of a mixture of AlCl3–NaCl–KCl. The reaction is an oxidative cationic polymerization but, in contrast with the reactions of the ordinary aromatic compounds which gave the corresponding polyaryls, in the cases of aromatic amines the reaction was regiospecific and stopped at the stage of biaryl to yield benzidine derivatives.
Amidrazones and Related Compounds. IV. The Cyclization of Hydrazidines to 2,3,4,5-Tetrahydro-1,2,4,5-tetrazine and 4-Amino-1,2,4-triazole Derivatives
Authors: Takahashi Masahiko , Tan Hideya , Fukushima Kunio , Yamazaki Hiroaki
Published: July 2006

Three methods of cyclization of hydrazidines are described. The reaction of N4-arylhydrazidines (2) with dimethyl acetylenedicarboxylate in refluxing tetrahydrofuran afforded 6-alkyl and aryl-2-aryl-3-methoxycarbonyl-3-methoxycarbonylmethyl-2,3,4,5-tetrahydro-1,2,4,5-tetrazines (3). Oxidation of N4-aryl-N2-arylmethylenehydrazidines (6) with mercuric oxide in refluxing ethanol gave 3-alkyl and aryl-5-aryl-4-arylamino-1,2,4-triazoles (7). 3-Alkyl and aryl-4-arylamino-1,2,4-triazoles (7f, g) were obtained upon the heating of (2a, e) in formic acid.
Synthetic Proof for the Structures of Maturinone and Cacalol
Authors: Inouye Yoshinobu , Uchida Yuji , Kakisawa Hiroshi
Published: July 2006

By unambiguous syntheses, the structures of maturinone and cacalol were shown to be 3,5-dimethylnaphtho[2,3-b]furan-4,9-dione (1) and 5,6,7,8-tetrahydro-3,4,5-trimethylnaphtho[2,3-b]furan-9-ol (2), respectively. 3,8-Dimethylnaphtho[2,3-b]furan-4,9-dione (1a), an isomer of maturione, was also synthesized.
Notes on the Formations of Oxaziridines by the Irradiation and Benzoylation of (22S, 25S)-N-Acetyl-11a-aza-c-homo-5α-veratra-11a,13(17)-diene-3β,11β,23β-triol 11a-Oxide, a Fused 6-Membered-ring Nitrone
Authors: Suginome Hiroshi , Mizuguchi Terutoshi , Masamune Tadashi
Published: July 2006

The irradiation of the title nitrone (5) with monochromatic light afforded a single isomeric oxaziridine (6), which reverted to the original nitrone (5) thermally at room temperature. The title nitrone was also converted into another oxaziridine (8) by treatment with benzoic anhydride.
Chemical Synthesis of Antigenic Determinants in Hen Egg-White Lysozyme. I. Heneicosapeptide Corresponding to Positions 34–54 in the Primary Structure
Authors: Mitaki Takayuki , Shimonishi Yasutsugu
Published: July 2006

For elucidating one of the antigenic determinants of hen egg-white lysozyme close to its catalytic site, heneicosapeptide was synthesized by a conventional method. This peptide, phenylalanylglutamylserylasparaginylphenylalanylasparaginylthreonylglutaminylalanylthreonylasparaginylarginylasparaginylthreonylaspartylglycylserylthreonylaspartyltyrosylglycine, corresponds to positions 34–54 of the amino acid sequence of hen egg-white lysozyme.
The Reflection Spectra of the Crystalline Electron Donor-Acceptor Complexes of TCNQ
Authors: Tanaka Masashi
Published: July 2006

The polarized reflection spectra were measured on the crystals of TCNQ complexes with phenothiazine, anthracene, pyrene, acenaphthene, carbazole, hexamethylbenzene, and 1,10-phenanthroline. The crystalline absorption spectra were obtained by the K-K transformation of the reflection spectra. The charge-transfer degree and the stabilization energy in the ground state were estimated for each complex by analysing the charge-transfer bands in the solid state. The charge-transfer degree of the TCNQ–phenothiazine complex is 19.6%, while those of the TCNQ–carbazole, anthracene, and hexamethylbenzene complexes are 12.0, 10.5, and 8.0% respectively. Furthermore, those values for TCNQ–1,10-phenanthroline, acenaphthene, and pyrene are about 5%. The relationship between the charge-transfer excitation energy and the ionization potential of a series of the donor molecules is also discussed.
Bond Orbital Calculations on the Methane and Silane Molecules. II. Vertical Transition Energies of the Lower Singlet-Excited States of CH4
Authors: Katagiri Shigeyoshi , Kohda-Sudoh Susumu
Published: July 2006

The vertical singlet-transition energies of CH4 were calculated using the BO method. Two types of basis sets, minimal and extended, were employed. The vertical transition energy of the lowest singlet state of CH4 was found to be 9.1 eV using the extended-basis set. This transition is assigned to a Rydberg-type transition in agreement with experiments. The other lower excited-states of CH4 may also be assigned to Rydberg transitions. The main features of the present BO calculations do not differ greatly from those of other extended-basis MO calculations. The total energy of the ground state is discussed briefly.
Study of Solutions of Tetraalkylammonium Salts in Acetone by Vapor Pressure Osmometry and Conductometry
Authors: Lee Ha Chung , Miyahara Yutaka
Published: July 2006

Vapor pressure depressions at 40.3 °C and electric conductivities at 25 and 40.3 °C have been measured for Bu4NCl, Bu4NBr, Bu4NI, and Pr4NI in acetone. Experiments were carried out with the greatest care to minimize the contact of salts and their solutions with air. A new representation of activity coefficients has been proposed for the undissociated species. Analysis by means of the representation gives better agreement between the dissociation constants and those obtained from electric conductivities. The very small dissociation constant of Bu4NCl found previously has been corrected.
A New Expression for Excess Volumes of Binary Mixtures
Authors: Kato Masanao , Suzuki Nobuo
Published: July 2006

A new expression for excess volumes of binary mixtures is derived. This equation contains four adjustable but physically-meaningful parameters: two non-randomness factors and two partial molar volumes at infinite dilution. The applicability of this equation is tested against data in the literature for several non-ideal mixtures, and it is found that this equation successfully expresses the experimental curves of excess volume, VE, over the entire concentration range. Furthermore, it is demonstrated that the non-randomness factors used in the excess volume expression can be used to estimate the excess Gibbs energy, GE, of binary mixtures based on the Wilson equation.
Kinetics of the Reaction at the Silver Sulfide–Liquid Sulfur Interface
Authors: Sasaki Jun , Mizusaki Junichiro , Fueki Kazuo
Published: July 2006

The reaction rate, v, at the Ag2S/S(1) interface was determined as a function of the silver activity aAg in Ag2S utilizing a solid-state electrochemical cell, Ag/AgI/Ag2S/Pt. The rate equation was found to be expressed by v=k(aAg)2–k′ On the basis of the theory by Kobayashi and Wagner, the rate-controlling step of the Ag2S/S(1) interface reaction is concluded to be S−(ad)+e→S2−(ad). The overall reaction rate of silver sulfidization by liquid sulfur can be well explained by the mixed control of a three-step reaction; the Ag2S/S(l) interface reaction, the diffusion of silver ions in Ag2S, and the Ag/Ag2S interface reaction.
Diffusional and Conductive Membrane Permeabilities to Ions in Liquid Membrane-Aqueous Inorganic Electrolyte System
Authors: Nomura Kazuo , Matsubara Akira , Kimizuka Hideo
Published: July 2006

Utilizing a liquid membrane-aqueous inorganic electrolyte system, the membrane permeability to ion α estimated from the conductance and potential data, Pα, and that at zero electric current estimated from the salt flow and potential data, Pα0, were determined. A solution of calcium hexadecyl sulfate dissolved in 1-octanol and calcium chloride were used as the liquid membrane and the inorganic electrolyte, respectively. The results showed that Pca0⁄Pcl0≈Pca⁄Pcl≈10 and Pcl0≈Ps0, where subscript s refers to the salt. The latter result indicates that the diffusion of a salt through the membrane is governed by the co-ion permeation. It was shown that Pα0 is smaller than Pα and that Pα decreases with increase in the concentration of external calcium chloride solution while Pα0 is nearly independent of the concentration. The difference between Pα and Pα0 can be explained in terms of the elements of permeability and conductance matrices estimated from the electrical and salt flow data.
Polarized Absorption Spectra of Single Crystals of Tetrathiafulvalenium Salts
Authors: Sugano Tadashi , Yakushi Kyuya , Kuroda Haruo
Published: July 2006

The polarized absorption spectra over the range, 5000–37000 cm−1, were observed on the single crystals of the highly-conductive, mixed-valence tetrathiafulvalenium salts, (TTF)Br0.71, (TTF)I0.71, and (TTF)(SCN)0.57, by using a microspectrophotometer. The spectra of these crystals were very similar to each other. The observed spectra were successfully interpreted in terms of the localized model, considering the charge transfer transitions between TTF species and the local excitations associated with the intramolecular transitions of the molecule and ion of TTF. The spectrum of the (TTF) (ClO4) crystal were also studied to aid the interpretations of the spectra of the mixed-valence TTF salts.
The Interaction Potential Surfaces for Alkali-trimers
Authors: Mohammad S Noor
Published: July 2006

Semi-empirical potential energy surfaces for some alkali-trimer complexes have been calculated using the simplest form of London equation. In the calculations use has been made of two new exponential potentials for the singlet and triplet states of diatomic molecules. The calculated potential surfaces at small internuclear distances show shallow well extending into the entrance and exit valleys without an energy barrier. The complexes are seen to be stable over all configurations; they are most stable however in the linear symmetric configuration. The force constants corresponding to bending and stretching deformations have been calculated for homonuclear trimers only. It has been observed that unlike stretching, the bending deformations do not sensitively affect the energy variation of the ground state.
Multidentate Ligand Kinetics. II. The Ligand Substitution Reactions of the Triethylenetetraminecadmium(II) Ion and the Tetra-ethylenepentaminecadmium(II) Ion with the Ethylene-diaminetetraacetatocuprate(II) Ion
Authors: Katsuyama Tetsuo , Kumai Toshihiko
Published: July 2006

The kinetics and mechanism of the ligand-substitution reactions of triethylenetetraminecadmium(II) ion (Cd(II)-trien) and tetraethylenepentaminecadmium(II) ion (Cd(II)-tetren) with ethylenediaminetetraacetatocuprate(II) ion (Cu(II)-edta) were studied spectrophotometrically at I=0.2 M (1 M=1 mol dm−3) and at 25.0 °C. The ligand-substitution reactions were catalyzed by traces of either edta or the polyamine (triethylenetetramine and tetraethylenepentamine). The substitution reactions were shown to proceed by means of a chain reaction mechanism where the chain-propagating steps are the reactions of the metal complexes with the free ligands. Each chain-propagating step was investigated. The ligand-substitution reactions of Cd(II)-trien and Cd(II)-tetren with edta were studied by the use of the chain reactions in the pH range of 8.8–10.2. The rate law is expressed as: −d[CdR2+]/dt=kL[CdR2+][edta4−]+kHL[CdR2+][Hedta3−], where R refers to trien or tetren. The rate constants, kL and kHL, were determined at 25.0 °C and I=0.2 M as: kL=(1.3±0.2)×106 M−1 s−1 and kHL=(6.5±1.5)×104 M−1 s−1 for Cd(II)-trien, and kL=(3.6±0.4)×105 M−1 s−1 and kHL=(1.0±0.2)×104 M−1 s−1 for Cd(II)-tetren.
The Stereochemistry of Copper(II) Complexes Containing N,N′-Di-8-quinolylethylenediamine and Its Optically Active Derivatives
Authors: Suzuki Toshishige M , Kamiyama Shin-ichi , Kimura Tetsuo
Published: July 2006

Copper (II) complexes of a series of quadridentate ligands, N,N′-di-8-quinolylethylenediamine (dqen), (R)-N,N′-quinolylpropylenediamine {(R)-dqpn}, and (R,R)-N,N′-di-8-quinolyl-1,2-cyclohexanediamine -{(R,R)-dqchxn}, have been prepared. Their d-d absorption spectra, magnetic moments, and molar conductivities indicate that the complexes have a five-coordinated structure, in which one of the quinoline groups of the ligands occupies an apical position. The circular dichroism (CD) spectra of the optically active ligands and their complexes exhibit exiton couplets in the ligand’s π*←π transition region. From the signs of the couplets, the preferable configurations of the (R)-dqpn and (R,R)-dqchxn complexes are assigned to Δ.
Reaction between Vanadium Trichloride Oxide and Hydrogen Sulfide
Authors: Yajima Akimasa , Matsuzaki Ryoko , Saeki Yuzo
Published: July 2006

The details of the reaction between vanadium trichloride oxide and hydrogen sulfide were examined at 20 and 60 °C. The main products by the reaction were vanadium dichloride oxide, sulfur, and hydrogen chloride. In addition to these products, small amounts of vanadium trichloride, vanadium tetrachloride, disulfur dichloride, and sulfur dioxide were formed. The formations of the above-mentioned reaction products can be explained as follows: The first stage is the reaction between vanadium trichloride oxide and hydrogen sulfide, 2VOCl3(1)+H2S(g)→2VOCl2(s)+S(s)+2HCl(g). Then the resulting sulfur reacts with the unreacted vanadium trichloride oxide, 2VOCl3(1)+2S(s)→2VOCl2(s)+S2Cl2(1). The resulting disulfur dichloride subsequently reacts with the unreacted vanadium trichloride oxide, 2VOCl3(1)+S2Cl2(1)→2VCl4(1)+S(s)+SO2(g). The resulting vanadium tetrachloride reacts with the sulfur formed during the reaction, 2VCl4(1)+2S(s)→2VCl3(s)+S2Cl2(1), and also reacts with hydrogen sulfide, 2VCl4(1)+H2S(g)→2VCl3(s)+S(s)+2HCl(g).
Synthesis and Properties of Metal Complexes with 2-Thiophenealdehyde Oxime
Authors: Kuma Hiro , Motobe Kyoji , Yamada Shoichiro
Published: July 2006

Cobalt(II), nickel(II), copper(II), zinc(II), and manganese(II) complexes with 2-thiophenealdehyde oxime have been prepared and characterized mainly on the basis of electronic spectra and magnetic data. The cobalt(II) and nickel(II) complexes isolated are of the general formulae: (A) MX2(oxime)4 (X=Cl, Br); (B) M(NCS)2(oxime)2. These compounds and ZnCl2 (oxime)4 are all six-coordinated, and the complexes (B) are probably multinuclear. Copper(II) and manganese(II) form complexes of the formula MX2 (oxime)2 (X=Cl, Br). Possible structures for these complexes are also discussed. 2-Thiophenealdehyde oxime is unidentate in all these complexes, being coordinated through the nitrogen atom.
The Crystal Structure of Iron Particles Dispersed in a Glasslike Carbon Matrix
Authors: Omori Mamoru , Hirai Toshio , Yajima Seishi
Published: July 2006

Ultra-fine iron particles were dispersed in a glasslike carbon matrix by the heat treatment of acetylferrocenefurfural resins. The dispersed iron particles were investigated by means of X-ray and electron diffraction analyses and by means of electron microscopy. In resins heat-treated at 400 °C, iron particles of varying diameters were observed by means of electron microscopy. The crystal structure of the iron particles was analyzed by means of X-ray and electron diffractions. Finely subdivided iron particles were identified as hexagonal, close-packed (hep) and expanded, body-centered cubic (bec) irons. The hep iron is the high-pressure phase of iron metal. The ultra-fine iron particles were coagulated to larger particles by heat treatment above 400 °C. The size of their unit cell was the same as that of standard bec iron.
A Study of the Mass Spectrum of Phenazine
Authors: Eguchi Shizuko
Published: July 2006

The mass spectrum of phenazine, a nitrogen-containing aromatic compound, was investigated in detail using a combination of ion kinetic energy spectroscopy and defocusing technique. In the fragmentation of the singly charged ions the molecular ion lost H· in the first stage to give an [M−1]+ or [M−2]+ ion, which was degraded via the expulsion of CN· or C2H2 in the next stage and of HCN or C2H3· in a later stage. Doubly charged ions also appeared in considerable intensity, and the fragmentation sequence differed significantly from that of the singly charged ions.
13C Spin-lattice Relaxation and Molecular Structure. II. The Application of 13C Spin-lattice Relaxation Times (T1) to Assignments of Signals in the Proton-decoupled 13C NMR Spectrum of 5-Ethyl-5H-dibenzophosphole
Authors: Hayashi Teruyuki , Nakanishi Hiroshi
Published: July 2006

The spin-lattice relaxation times (T1) of the 13C nuclei in 5-ethyl-5H-dibenzophosphole (1) were studied. The 13C NMR signals of the quarternary carbons of 1 in the aromatic region, whose assignments are very difficult by other techniques, were successfully assigned by means of the spin-lattice relaxation method. The dipolar relaxation terms and their reciprocal values were calculated by the use of the internuclear-distances between the carbon nuclei and hydrogen or phosphorus ones, and were compared with the observed T1 values. It was found by studying the observed T1’s of the ethyl group in 1 that the rotation around the C–P bond is more strongly restricted than that around the C–C single bond.
α,β-Unsaturated Carboxylic Acid Derivatives. XIV. The Synthesis and Reduction of Diels-Alder Adducts from Ethyl 3-Nitro-2-alkenoates and Cyclopentadiene
Authors: Shin Chung-gi , Kosuge Yasuhiro , Yamaura Masanori , Yoshimura Juji
Published: July 2006

The Diels-Alder reactions of cyclopentadiene with ethyl (E)- and (Z)-3-nitrocrotonate were carried out to give only the (2+4)-nitro adduct as a mixture of three diastereomers, while that of the diene with ethyl (Z)-3-nitrocinnamate gave two kinds of cycloaddition products, (2+2)- and (2+4)-nitro adducts. All the nitro adducts were reduced with aluminum-amalgam to give the corresponding mono- and dihydroxyamino compounds, in which vicinal endo-ethoxycarbonyl-endo-hydroxyamino derivatives cyclized readily to give tricyclic compounds containing isoxazolidinone ring. The stereochemistry of all the new compounds were established on the basis of IR and NMR spectroscopic analyses.
Polyelectrolyte Complexes of Chitosan with Sodium Carboxymethyldextran
Authors: Fukuda Hiroshi , Kikuchi Yasuo
Published: July 2006

Mixing of chitosan with sodium carboxymethyldextran having opposite charge gave rise to the formation of novel water-insoluble precipitates. The mole ratios of N/COO− in the polyelectrolyte complexes thus prepared were estimated to be 0.248–1.658. It was found that pH, mole ratio of N/Na and the order of mixing play an important role in determining the composition ratio of N/COO− in the polyelectrolyte complexes. IR spectroscopic studies, blood clotting test, elementary analyses, the color reaction with Toluidine Blue and studies on solubility of polyelectrolyte complexes revealed that there is no noticeable interactions between –COOH groups and –OH groups. However, the –NH3+ groups in chitosan participate in the binding with carboxymethyldextran, probably through its –COO− groups, in the polyelectrolyte complexes. It seems that the number of binding sites between –NH3+and -COO− groups in the polyelectrolyte complexes at pH 3.0 is smaller than those prepared at pH 6.5. Both the polyelectrolyte complexes prepared at pH 3.0 and 6.5 suppressed the coagulation of blood. This anti-thrombogenic property should be related to elution of anti-thrombogenic carboxymethyldextran.
Formation of Cyanonitro-3-cyclohexen-1-ones in the Reaction of Tetramethylbenzonitriles with Fuming Nitric Acid
Authors: Suzuki Hitomi , Inoue Akiyoshi , Koge Mamie , Hanafusa Terukiyo
Published: July 2006

The reaction of 3,4,5,6-tetramethylbenzene-1,2-dicarbonitrile with fuming nitric acid at room temperature yielded appreciable amounts of 3,4-dicyano-5,6-dinitro-2,2,5,6-tetramethyl-3-cyclohexen-1-one and 3,4-dicyano-6-hydroxy-5-nitro-2,2,5,6-tetramethyl-3-cyclohexen-1-one in addition to the expected side-chain substitution products. 2,3,5,6-Tetramethylbenzonitrile similarly gave 3-cyano-5,6-dinitro-2,2,4,5-tetramethyl-3-cyclohexen-1-ones as minor products. The structures of these nitro ketones have been assigned by spectral methods and a probable mechanistic pathway to their formation is presented.
Sulfur-Carbonyl Interaction in Rigid β-Keto Sulfides
Authors: Tabushi Iwao , Tamaru Yoshinao , Yoshida Zen-ichi
Published: July 2006

The electron donating ability of sulfur to a positively charged center through space was examined by means of ultraviolet spectroscopy. 7-Thiabicyclo[2.2.1]heptan-2-one and -2,5-dione exhibited finely separated charge transfer band (from divalent sulfide to carbonyl) at 260 nm in UV spectra, the longest wave-length for S–Cco charge transfer band so far reported. The assignment of these CT bands was confirmed by comparison with relevant reference compounds.
Synthesis of Indole Derivatives by Cu2O-Catalyzed Cyclization of o-(α-Cyanoalkyl)phenyl Isocyanides and o-[α-(Methoxy-carbonyl)alkyl]phenyl Isocyanides
Authors: Ito Yoshihiko , Inubushi Yoshinori , Sugaya Toru , Kobayashi Kazuhiro , Saegusa Takeo
Published: July 2006

o-(Cyanomethyl)phenyl isocyanide and o-(methoxycarbonylmethyl)phenyl isocyanide were heated with a catalytic amount of Cu2O in benzene to give 3-cyanoindole and 3-(methoxycarbonyl)indole in 86 and 92% yields, respectively. Lithiations of o-(cyanomethyl)phenyl isocyanide and o-(methoxycarbonylmethyl)phenyl isocyanide with butyllithium at −78 °C followed by the reaction with alkyl halides such as methyl iodide, allyl bromide, butyl bromide, benzyl bromide and methyl α-bromoacetate afforded the corresponding o-(α-cyanoalkyl)phenyl isocyanides and o-[α-(methoxycarbonyl)alkyl]phenyl isocyanides. o-(α-Cyanoalkyl)phenyl isocyanides and o-[α-(methoxycarbonyl)alkyl]phenyl isocyanides thus obtained were also cyclized by Cu2O catalyst producing 3-alkyl-3-cyano-3H-indoles and 3-alkyl-3-(methoxycarbonyl)-3H-indoles, respectively, in moderate yields.
Stereochemistry of Nucleophilic Addition Reactions. 6. Synthesis of Isoxazoline N-Oxide Derivatives from Methyl 4,6-O-Benzylidene-2,3-dideoxy-3-nitro-α-d-erythro-hex-2-enopyranoside with Some S-Ylides
Authors: Sakakibara Tohru , Sudoh Rokuro
Published: July 2006

In the reactions of dimethyloxosulfonium methylide, dimethylsulfonium ethoxycarbonylmethylide, and dimethylsulfonium phenacylide with the title compound, axial attack predominates over equatorial attack, particularly in the case of dimethylsulfonium phenacylide equatorial attack being no longer observed. Axial attack afforded exclusively 1,4-addition products (isoxazoline N-oxide derivatives), whereas equatorial attack gave only 1,2-addition products (cyclopropane and stabilized ylide, respectively). Discussion is given on such high selectivities.
The Thermal Decomposition Process of Calcium Sulfite
Authors: Matsuzaki Ryoko , Masumizu Hagio , Murakami Nagisa , Saeki Yuzo
Published: July 2006

The thermal decomposition of calcium sulfite at temperatures below 880 °C in an argon stream was examined. Also, the reaction between calcium sulfate and calcium sulfide, which were formed during the decomposition process of calcium sulfite, was examined. The thermal decomposition process of calcium sulfite can be represented as follows: on heating calcium sulfite, the reaction, CaSO3→CaO+SO2, occurs above about 600 °C. Above about 680 °C, the reaction, 4CaSO3→3CaSO4+CaS, occurs besides the above reaction. Furthermore, the reaction between calcium sulfate and calcium sulfide which are formed during the decomposition process of calcium sulfite, 3CaSO4+CaS→4CaO+4SO2, occurs above about 780 °C.
The Oxidation Mechanism of Copper in Nitrogen Oxide
Authors: Takasu Yoshio , Matsuda Yoshiharu
Published: July 2006

The rate-determining step of the oxidation of copper in nitrogen oxide was proposed to be the dissociation of the adsorbed nitrogen oxide on the surface of the oxide film.
Analysis of the NMR Line Shape Dually Modulated by the Chemical Exchange and by the Scalar Coupling Relaxation. 13C NMR Spectrum of the Trimethylaluminum Dimer
Authors: Yamamoto Osamu , Yanagisawa Masaru
Published: July 2006

13C methyl signals of the trimethylaluminum dimer, broadened by the chemical exchange and the scalar coupling interaction with 27Al, were analyzed in order to obtain the rates of the bridge-terminal exchange of the methyl groups. The exchange rates were compared with those obtained from the 1H resonance, and a good agreement was obtained. A brief discussion is given of some advantages and difficulties of the analysis.
The Anodic Voltammetry of Deoxyribonucleic Acid at a Glassy Carbon Electrode
Authors: Yao Toshio , Wasa Tamotsu , Musha Soichiro
Published: July 2006

Deoxyribonucleic acid was oxidized in two steps at a glassy carbon electrode. The peak currents had the characteristics of adsorption currents, but if the surface of the electrode was not fully covered by the adsorbed polynucleotide molecule the peak currents had rather the characteristics of diffusion-controlled currents.
Synthesis of 4-Methyl-1,2-oxathiin 2,2-Dioxide
Authors: Akiyama Tetsuo , Sugihara Masaki , Imagawa Takeshi , Kawanisi Mituyosi
Published: July 2006

The reaction of isoprene with the SO3-DMF complex afforded isoprene δ-sultone (3) in a 48% yield. The addition of bromine to 3 gave a dibromo product (4) and successive treatment of 4 with triethylamine in benzene and with triethylamine in the presence of silver tetrafluoroborate gave 4-methyl-1,2-oxathiin 2,2-dioxide in an 18% yield.
Synthetic Photochemistry. XII. The Sensitized Photooxidation Reaction of Some Spirocyclic Derivatives of Vinylcyclopropanes
Authors: Takeshita Hitoshi , Hatsui Toshihide , Iwabuchi Ryuta , Itoh Shinji
Published: July 2006

The dye-sensitized photooxidation of the Diels-Alder adducts prepared from 2-substituted tropones and spiro[2.4]hepta-4,6-diene was caried out. A marked difference in the reactivities was observed between the two structural types of adducts; 3,3-ethylene derivatives gave nor-epoxides, but 5,5-ethylene derivatives resulted in the recovery of the starting materials.
The Reaction of Decaborane with Carbonyl Compounds
Authors: Tanaka Toyosuke , Matsuda Tsuneo , Kimijima Katsunori , Iwasaki Yuichi
Published: July 2006

Decaborane formed adducts with cyclohexanones, 2-octanone, acetaldehyde, or acetone, which were cleft in the presence of water into alcohols, boric acid, and hydrogen. Olefins and boroxins as secondary products were identified.
New Synthesis of γ-Hydroxyglutamic Acid
Authors: Kusumi Takenori , Kakisawa Hiroshi , Suzuki Shinnichiro , Harada Kaoru , Kashima Choji
Published: July 2006

γ-Hydroxyglutamic acid was prepared easily via 3-ethoxycarbonyl-5-methoxycarbonyl-2-isoxazoline, which was the 1,3-dipolar adduct of methyl acrylate and ethyl cyanoformate N-oxide.
Bromine-81 Nuclear Quadrupole Resonance and Aluminum-27 Nuclear Magnetic Resonance in AlBr3 Complexes
Authors: Okuda Tsutomu , Ishihara Hideta , Yamada Koji , Negita Hisao
Published: July 2006

The Zeeman effect on 81Br NQR and the quadrupole effect on 27Al NMR in l·AlBr3 complexes (L=KBr, POBr3, and H2S) were studied at room temperature. It was found that the 27Al quadrupole-coupling constant for these complexes decreases with decreasing coupling constant of the 81Br atom in –AlBr3 and that the atomic arrangement about the Al atom has C3V symmetry in POBr3·AlBr3 and H2S·AlBr3. In the latter complex, H2S molecule is reorientated at room temperature. The amount of charge transfer in these complexes was estimated on the basis of the Townes-Dailey theory and the bond angle ∠Br–Al–Br was found to depend on the amount of the charge transfer. The temperature dependence of the 81Br NQR frequencies was observed in order to obtain information about molecular motion in H2S·AlBr3 and POBr3·AlBr3.
Generation of Olefin Metathesis Catalysts from W(CO)6 and Group IVa Metal Halides under Photochemical Conditions
Authors: Nagasawa Megumu , Kikukawa Kiyoshi , Takagi Makoto , Matsuda Tsutomu
Published: July 2006

Irradiation of a solution of W(CO)6 and group IVa metal halides in benzene by UV light gave the olefin metathesis catalysts, of which the combination W(CO)6–TiCl4 was the most effective. Association of the coordinatively unsaturated W(CO)5 and TiCl4 was suggested to be a key step in the formation of a catalytically active complex. A survery was also made for other W(CO)6–MXn combinations for photo-generation of metathesis catalyst.
Electrostatic Force Study with Floating Wave Function. Comparative Study on the Origins of the Molecular Shapes of CH3+ and NH3
Authors: Nakatsuji Hiroshi , Matsuda Kazuo , Yonezawa Teijiro
Published: July 2006

The force and density origins of the molecular shapes of CH3+ and NH3 are studied comparatively on the basis of the floating wave functions which satisfy the Hellmann-Feynman theorem for the forces acting on the terminal protons. It is confirmed quantitatively that the previous concepts of the electrostatic force (ESF) theory correctly grasp the origins of the molecular shapes. Namely, the density-guiding  rule which states that the nuclei are pulled in the direction of the electron-cloud reorganization i.e., the electron-cloud preceding and incomplete following), is verified as the density origin. The force origin which is the AD and EC forces reflects and quantifies the density origin. The roles of the other forces are also easily predicted by the ESF theory.
The Effects of Halide Ions on the Radiation-induced Decoloration of Azo and Anthraquinone Dyes in N2O-saturated Aqueous Solutions
Authors: Suzuki Nobutake , Tokunaga Okihiro , Washino Masamitsu
Published: July 2006

The radiation-induced decoloration of azo and anthraquinone dyes was studied in N2O-saturated aqueous solutions containing halide ions. In the N2O-saturated solutions, the decoloration yield, G(–Dye), increased markedly upon the addition of Br− and I−, which are efficient scavengers of the OH radical. In the nitrogensaturated solutions, however, the G(–Dye) decreased upon the addition of Br− and I−. Such an increase in the G(–Dye) upon the addition of Br− and I− in the N2O-saturated solutions is mainly attributable to the attacks of the halide radical anions, Br2− and I2−, on the ring structure of the dyes. On the other hand, the G(–Dye) was not changed upon the addition of Cl− in the N2O-saturated solution. This may be attributable to the very slow rate of the formation of Cl2− in a neutral solution.
Phase Equilibria in the Lu2O3–V2O3–V2O5 System at 1200 °C
Authors: Kitayama Kenzo , Katsura Takashi
Published: July 2006

The phase equilibria in the Lu2O3–V2O3–V2O5 system were established at 1200 °C. In this system, Lu2O3, LuVO3 LuVO4, V2O3, V3O5, V4O7, V5O9, V6O11, V7O13, and three new compounds Lu7V3O16, Lu2V2O7, and LuV4O8 are stable. LuVO4, V2O3, VO2, Lu7V3O16, Lu2V2O7, and LuV4O8 have non-stoichiometric compositions. The relationships between the composition and the −logPO2 values of the solid solutions were obtained from the thermogravimetric results. On the basis of the phase equilibria, the standard Gibbs free energies of several reactions were determined. The spacings, relative intensities, and densities of new compounds were also determined.
Liquid-phase Oxidation of Hydrocarbons with Molecular Oxygen. I. The Effects of Metal Ions and Their Ligands on Product Distribution in the Oxidation of Tetralin in Acetic Acid
Authors: Mizukami Fujio , Imamura Juichi
Published: July 2006

Metal-ion catalyzed oxidation of tetralin and metal-ion catalyzed decomposition of α-tetralin hydroperoxide (THP) were carried out in acetic acid in both the presence and absence of an additive. It was found that the rate-determining step in the oxidation of tetralin is the decomposition of THP. The results also suggest that the decomposition of THP with cobalt catalysts proceeds by the inner-sphere mechanism. In the oxidation of tetralin catalyzed by first-transition-metal ions, excepting vanadium, cobalt showed the highest activity and the lowest selectivity of hydroperoxide, and chromium showed the highest ratio of α-tetralone to α-tetralol (On/Ol). The order of the activities of metal acetates in producing oxidation is in agreement with that of the activities of metal acetates in producing decomposition. Such agreement was also found for Co(acac)3, Cr(acac)3, Mn(acac)2, and Fe(acac)3 catalysts. For oxidation with Co(OAc)2·4H2O and Cr(OAc)3, the product distributions were examined for various conversions of tetralin. In the both cases, the On/Ol ratios increase with increasing tetralin conversion. However, the mechanisms responsible for the increase in the On/Ol ratio appear to be different.
Metalloporphyrins. III. Photoinduced Acylamination of Zinc Porphyrins by Use of Acyl Azides
Authors: Ichimura Kunihiro
Published: July 2006

Visible light irradiation of a solution of zinc octaethylporphin (ZnOEP) in the presence of acyl azide gives zinc complex of 5-acylamino-2,3,7,8,12,13,17,18-octaethylporphin together with a small amount of zinc complex of 21-acylamino-2,3,7,8,12,13,17,18-octaethylporphin. Zinc 5,10,15,20-tetraphenylporphin (ZnTPP) is coverted into zinc complex of 21-acylamino-5,10,15,20-tetraphenylporphin in a similar way. The pyrolysis of the N-acylaminated ZnOEP affords the rearrangement product in addition to ZnOEP, while N-acylaminated ZnTPP is converted into ZnTPP on heating. The spectroscopic properties of these photoproducts are given.
The Reactions of a Variety of Diazo Compounds with Sulfur Dioxide in Ethanol
Authors: Tanabe Toyoshige , Nagai Toshikazu
Published: July 2006

The reactions of several diazomethanes bearing a variety of substituents with sulfur dioxide were carried out in ethanol. The reaction of a diazomethane possessing an electron-releasing group gave the olefin as the major product. On the contrary, the ethyl ethers were predominantly afforded from the reactions of the diazomethanes containing an electron-withdrawing group. Moreover, the ethyl alkanesulfonates were obtained in the cases bearing the substituent of an intermediate electronic character. The observed product distribution is interpreted in terms of the nucleophilicity of the α-carbon atom of the diazomethane: the preference of the formation of sulfene by the electrophilic attack of SO2 on the diazomethane to the acid-catalyzed decomposition by ethyl hydrogen sulfite reflects the nucleophilicity of the α-carbon atom in the diazomethane.
Syntheses and Reactions of 10-(2,2′-Biphenylylene)-9-phenanthrone Derivatives and Some Consideration of Ethyl Isomers in Their Analogous Series
Authors: Ooya Takao , Minabe Masahiro , Suzuki Kazuo
Published: July 2006

The Wagner-Meerwein rearrangement of 9′-methyl-9,9′-bifluoren-9-ol yielded 10-(2,2′-biphenylylene)-9-methylenephenanthrene. Ozonolysis of the phenanthrene afforded 10-(2,2′-biphenylylene)-9-phenanthrone. This pinacolone was converted into 2′-(9-fluorenyl)biphenyl-2-carboxylic acid. Oxidation of 4,9′-bifluoren-9-one, which was obtained by ring closure of the acid, gave 9′-hydroxy-, 9′-benzyl-, and 9′-benzyloxy-4,9′-bifluoren-9-one. Isomers of 2,2′-diethyl-9,9′-bifluorene-9,9′-diol were obtained by reduction of 2-ethyl-9-fluorenone. The pinacols were rearranged to the corresponding pinacolones, which were cleaved into carboxylic acids. The structural assignment of these isomers was made by spectral analyses.
The Reactions of Group V Metal Amide with Sulfur Dioxide
Authors: Ando Fumio , Koketsu Jugo , Ishii Yoshio
Published: July 2006

Tris(dialkylamino)-arsines (I), -stibines (II), and -bismuthines (III) react with sulfur dioxide to give the corresponding tetraalkylsulfurous diamides and the corresponding metal oxides or polymers containing the metals. The reactivity of these metal amides in view of the fastness of the initial reactions follows the order III>II>I, however, the yields decrease in the order I>II>III. Tris(dialkylamino)phosphines, on the other hand, give hexaalkylphosphoric triamides and hexaalkylphosphorothioic triamides in a ratio of 2 : 1. The reactivity of the various phosphorus compounds toward sulfur dioxide increases with increasing nucleophilicity of the phosphorus atom; P(NEt2)3>Ph2PNEt2>Ph2POEt>PhP(OEt)2>P(OEt)3. The reaction mechanism of compounds (I), (II), and (III) with sulfur dioxide is different from that of the phosphorus amides.
Synthetic Studies on Quinoxaline Antibiotics. Synthesis of Quinoxaline-2-carbonyl Tetradepsipeptide Derivatives Related to Triostin A
Authors: Shin Masaru , Inouye Ken , Otsuka Hideo
Published: July 2006

The synthesis is described of four quinoxaline-2-carbonyl (Qxc) tetradepsipeptide derivatives, Qxc–d-Ser[Z–MeCys(Bzl)–MeVal]–Ala–OH, Qxc–d-Ser[Bpoc–MeCys(Bzl)–MeVal]–Ala–OBut (2), Qxc-d-Ser(Z–MeVal)–Ala–MeCys(Bzl)–OH, and Qxc–d-Ser(Bpoc–MeVal)–Ala–MeCys(Bzl)–OBut, corresponding to the partial structure of a quinoxaline antibiotic, triostiin A. The Qxc group was introduced at the dipeptide or tripeptide stage with Qxc–ONp as acylating agent. Qxc–d-Ser–Ala–OBut and Qxc–d-Ser–Ala–MeCys(Bzl)–OBut were acylated with Z–MeVal–OH by using p-toluenesulfonyl chloride as activating agent to give the desired depsipeptides in excellent yields, whereas the acylation with Bpoc–MeVal–OH by the same procedure was unsuccessful. The latter could be achieved by the N,N′-carbonyldiimidazole method, though the yields were relatively low. The treatment of compound 2 with an aqueous acetic acid–formic acid mixture for removal of the Bpoc group brought about concomitant formation of cyclo[–MeCys(Bzl)–MeVal–].
Polymeric Alkoxyalkylaluminum Compounds by Novel Reductive Cleavage of Saturated Cyclic Ethers. A New Organometallic Reagent in Organic Synthesis
Authors: Sumitani Mitsuhiro , Kanemitsuya Kazuhiko , Yasuda Hajime , Tani Hisaya
Published: July 2006

Insertion of aluminum to the C–O–C bond of saturated cyclic ethers by the HgCl2–ZnCl2–MeI catalyst system led to the reductive cleavage of 5, 6, and 7 membered ring ethers to give polymeric alkoxyalkylaluminum compounds. The relative rate of the reaction was increased in the order of tetrahydrofuran, 3-methyltetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydropyran, oxepane, 7-oxabicyclo[2.2.1]-heptane, and 2-methyltetrahydropyran. The cleaved cyclic ethers are bonded with aluminum atoms bifunctionally and the resulting polymeric aluminum compound gave dideuterio alcohols upon deuterolysis. Addition reaction of allyl halides and reduction of chloral with the aluminum compound provided a novel route for the preparation of unsaturated alcohols.
Magnitude of Mercury Levels in Fish Muscle Tissue from South Carolina Waters
Authors: Koli Andrew K , McClary Edward
Published: July 2006

Many of the world’s great gastronomic materpieces are based on fish from both freshwater and saltwater. The danger for human health, due to fish consumption, has been very well recognized. A survey of mercury residues in freshwater fish was undertaken to see if the problem of the magnitude of mercury contamination was evident in the South Carolina Fishery. These investigations were initiated to determine mercury levels in fish from a variety of South Carolina Waters. Samples of fish from freshwater sources all over the state of South Carolina were collected during 1974 and 1975. The species composition of the collections generally reflects the fish populations of the water sampled. Mercury determinations were made on 100 samples of fish taken from 22 locations covering 46 South Carolina counties. Triplicate samples of fish tissues were analyzed using flameless atomic absorption procedures. Findings of this report are that magnitude of mercury levels of fish from Lake Jocassee and Edisto River have been found to be higher than other waterways surveyed. Mercury levels exceeding the U. S. Food and Drug Administration guideline of 0.5 ppm have been found in Brown Trout, Pike and Mudfish. Different patterns of mercury concentration occurred between different tissues. Larger fish contain higher concentration of mercury than do smaller fish of the same species.
CNDO/2 Calculations of MeSEt, MeS-n-Pr, MeS-n-Bu, (Et)2S, EtS-n-Pr, EtS-n-Bu, and (n-Pr)2S
Authors: Ohsaku Masaru , Bingo Norihisa , Fujiwara Hiroshi , Murata Hiromu
Published: July 2006

CNDO/2 sp calculations were carried out for MeSEt, MeS-n-Pr, MeS-n-Bu, (Et)2S, EtS-n-Pr, EtS-n-Bu, and(n-Pr)2S. The stable conformations of these molecules were discussed.