bluuebunny/crossref_metadata_2025 huggingface dataset:
The Diazo-coupling Reaction of Phenol in Organic Solvents. The Isomer Ratio
Authors: Yamada Hideo , Hashida Y\={o}ji , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

The ortho : para-ratios in the reaction of phenol with benzenediazonium fluoroborate have been investigated in organic solvents. It has been found that the o/p ratios in protic solvents were smaller than those in aprotic solvents. The results were interpreted in terms of the difference in solvation toward the phenolate ion.
Layered Compounds. XVIII. Synthesis of a Paracyclophane Containing the 1,2,3,4,5-Hexapentaene Group and the Stereochemistry of Its Formation
Authors: Negi Taichi , Kaneda Takahiro , Mizuno Hiroshi , Toyoda Toshihiro , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

Novel cyclic 1,2,3,4,5-hexapentaene compounds were synthesized from cyclic diyne-diol IX via diallene-dibromide X in order to study transannular electronic interaction. A diallene-dibromide Xc-I obtained from a diyne-diol isomer IXc-I was debrominated with active zinc to give cyclic hexapentaene IIc, whereas the other diallene-dibromide Xc-II derived from the second diyne-diol isomer IXc-II was not. The X-ray crystallographic analysis of the dibromide Xc-I was then carried out, and the s-trans structure was assigned to the dibromide. On the basis of this result, the stereochemistry of the transformation from diyne-diol to the hexapentaene group was discussed. The electronic spectrum of a cyclophane IIa containing the hexapentaene group showed a transannular π-electronic interaction between the benzene ring and the hexapentaene group, unlike those of the other hexapentaene derivatives, IIc and XV.
Effects of Substituents on the Formation of Acetals of 4-Substituted 1,3-Indandiones
Authors: Sakane Kazuo , Otsuji Yoshio , Imoto Eiji
Published: July 2006

Treatment of 4-nitrol,3-indandione (1) with an equivalent of ethylene glycol in benzene in the presence of p-toluenesulfonic acid afforded 4-nitro-1,3-indandione-1-ethylene acetal (2), 3-ethylene acetal (3) and 1,3-bisethylene acetal (4). Kinetic studies revealed that 2 is a kinetically preferred product and 3 is a thermodynamically preferred product. However, the reaction of 4-acetamido-1,3-indandione (5) with ethylene glycol under similar conditions gave 4-acetamido-1,3-indandione-1-ethylene acetal (6) as a product both kinetically and thermodynamically controlled. Thioacetalization of 1 with an equivalent of 1,2-ethanedithiol afforded selectively 4-nitro-1,3-indandione-1-ethylene thioacetal (9).
Phosphorimetric Investigation of Triplet-Triplet Energy Transfer in Fluid Solution
Authors: Takemura Takeshi , Aikawa Masayuki , Baba Hiroaki
Published: July 2006

The mechanism of triplet-triplet (T-T) energy transfer in fluid solution has been studied by means of phosphorimetry in the temperature range 0–60 °C with acetophenone as energy donor, 1,4-dibromonaphthalene as acceptor and isooctane, isopentane or carbon tetrachloride as solvent. From the temperature dependence of the energy transfer, α and kdif could be evaluated separately, kdif denoting the diffusion-controlled rate constant for the encounter of donor and acceptor molecules and αkdif corresponds to the rate constant for the overall energy transfer reaction. The α values are 0.28 at 25 °C in isopentane and 0.43 at 21 °C in isooctane, indicating that the T-T energy transfer process is not strictly diffusion-controlled. The kdif values are nearly equal to those predicted by a modified Debye equation.
The Electrodepositions of Copper and Nickel from Their Trifluoroacetate–Formamide Baths
Authors: Takei Tatsuko
Published: July 2006

The present author has been studying the electrodeposition of metals from non-aqueous solutions of metal trifluoroacetates. In the present study, the properties of the Cu(CF3COO)2–HCONH2 bath and the Ni(CF3COO)2–HCONH2 bath, and the mechanism of the electrodeposition of copper and nickel from these baths, were studied. Both Cu(CF3COO)2 and Ni(CF3COO)2 were easily dissolved in formamide. The specific conductance of these solutions was high. Satisfactory electrodeposits are obtained from these solutions, with a high current efficiency. The cross-section of the electrodeposits showed a granular structure. The rate of the electrodeposition of copper from the Cu(CF3COO)2–HCONH2 bath and that of nickel from the Ni(CF3COO)2–HCONH2 bath were controlled by the charge-transfer reaction at low current densities. The activation overvoltage of the hydrogen-evolution reaction for the electrolysis of the CF3COOH–HCONH2 bath was higher than that for the electrolysis of the CF3COOH–H2O bath.
Properties and Configuration of Manganese(II), Cobalt(II), Nickel(II), Copper(II) and Zinc(II) Chelates of Acetoacetylferrocene
Authors: Imai Hiromu , Ota Tadamasa
Published: July 2006

Physical and chemical properties of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) chelates of acetoacetylferrocene were investigated. The solubility decreased in the order CHCl3>CH2Cl2>C6H5Cl>C6H4(CH3)2>C6H6, the chelates being more soluble in pyridine. It was found from magnetic data that the configuration is octahedral for the aquo or pyridine adduct of manganese(II), cobalt(II) and nickel(II) chelates, square planar for anhydride of copper(II) chelate, distorted octahedral for its pyridine adduct, and quasi-tetrahedral for the anhydride of manganese(II) chelate. The d-d transition of electronic spectra was analysed by Ohsymmetry for cobalt(II) and nickel(II) chelates, and by C2h symmetry for copper(II) chelate. Assignment of the d-d transition for manganese(II) chelate was difficult.
The Polymorphism of Inosine. II. The Measurement of Solubilities in Water
Authors: Suzuki Yoshihisa
Published: July 2006

The solubilities of anhydrous inosine crystals in the α-form and in the β-form in water were determined in the temperature range between 20 °C and 60 °C. The results may be formulated as follows:

& α-form & logS=0.0190 t-0.065

& β-form & logS=0.0198 t-0.161

These data indicate that the β-crystals are more stable than the α-crystals over the whole temperature range examined. However, the difference in solubility is too small to induce the transition without seed crystals in the β-form, so that the α-crystals themselves are practically stable in water. The rate of the transition from the α-form to the β-form varies in proportion to the amount of the seed β-crystals. At low temperatures the dihydrate form of inosine is more stable than both of these two anhydrous forms. The solubility may be formulated as follows:

dihydrate-form logS=0.0314 t-0.276
Polymorphism of Inosine. III. The Equilibrium for the Inosine–Dimethyl Sulfoxide–Water System
Authors: Suzuki Yoshihisa , Hara Kentaro
Published: July 2006

The phase diagram for the inosine–dimethyl sulfoxide–water system was determined at 30 °C. Inosine in the α-form is more soluble than that in the β-form in aqueous DMSO. The difference in the solubilities between the two forms is small when the concentration of DMSO is below 50%. However, it becomes several times larger in 70% DMSO than in water. This is the reason why inosine in the β-form is often obtainable with ease from 70% DMSO in the absence of seed β-crystals, while it is with difficulty obtained only from water. When the concentration of DMSO becomes higher than 82%, a new solid phase is obtained. It consists of inosine with two mol of DMSO of crystallization. Inosine in the β-form is also obtainable with ease through the decomposition of these new crystals.
The Thermodynamic Properties of Tetraalkylammonium Halides in Acetone
Authors: Imura Masahiro , Nomura Hiroyasu , Kawaizumi Fumio , Miyahara Yutaka
Published: July 2006

The vapor-pressure depressions of solutions of four tetraalkylammonium halides in acetone were determined by means of a vapor-pressure osmometer. The experimental results were discussed by analyzing the relationship between the h(=1000lna1⁄M1m+1) function and the concentration. The following conclusions are obtained: tetraalkylammonium salts are dissociated in acetone, and the thermodynamic behavior of the dissociated species is described by the Debye-Hückel-Onsager limiting formula with sufficient accuracy, where the undissociated species are assumed to behave ideally.

Except for (n-Bu)4NCl, the dissociation constants determined by the present work are in good agreement with those found in the literature, which were determined conductometrically.
The Preparation of 3,5-DicMoro-2,4,6-trifluorophenyl(cyclopentadienyl)dicarbonyliron and Its Derivatives
Authors: Ishikawa Nobuo , Ibuki Shuji
Published: July 2006

3,5-Dichloro-2,4,6-trifluorophenyl(cyclopentadienyl)dicarbonyliron (4) was prepared by the nucleophilic substitution of sym-trichlorotrifluorobenzene with the (cyclopentadienyl)dicarbonyliron anion. One of the chlorine atoms of 4 was lithiated and the resulting lithio compound was hydrolyzed or carboxylated to give 3-chloro-2,4,6-trifluorophenyl(cyclopentadienyl)iron (6) or its 5-carboxylic acid (7) respectively.
The Solubility Study of Ion-pairs in Organic Solvents
Authors: Takamatsu Takejiro
Published: July 2006

The solubilities of alkali picrates were measured in alcohols (13 species) and esters (19 species) at 25±0.2°C. It was found that the solubility data are well correlated with the solubility parameters of the solvents. It is also pointed out that the distribution ratios of the cesium picrate between the aqueous phase and the organic phase are apparently correlated with the solubility parameters of the extraction solvents.
The Equilibria of Protonation Reaction of N,N′-Ethylenebis(salicylideneiminato) cobalt(II) and of Its Oxygenated Binuclear Complex by Perchloric Acid in Dimethyl Sulfoxide
Authors: Abe Yuriko , Wada Goro
Published: July 2006

Acid dependence of oxygen uptake by Co(II)salen in DMSO was studied. As the concentration of perchloric acid increases in the absence of O2, Co(II)salen forms 1: 1 and 1: 2 protonated complexes, with the formation constants K1=8.3×103 M−1 and K2=1.6×103 M−1 measured spectrophotometrically by the linearity method. The oxygen uptake ratio n of Co(II)salen in the absence of acid is 0.5, indicating formation of a 2: 1 O2-bridged binuclear complex, with an immeasurably large formation constant K3. The oxygenated complex is protonated by addition of acid with a formation constant K4=3.3×105 M−1 as observed again spectrophotometrically. When Co(II)salen is oxygenated in the presence of acid, n decreases considerably from 0.5 with increasing acid concentration. This is because the protonated Co(II)salen complexes are inert to oxygenation and both the rate of oxygenation of Co(II)salen and that of deoxygenation of oxygenated binuclear species are slow, as compared to the rapid processes of protonation.
Ringspaltungsreaktion von Thiadiazolo- und Triazolopyrimidin-Derivaten
Authors: Okabe Takayuki , Taniguchi Eiji , Maekawa Kazuyuki
Published: July 2006

The ring-opening and rearrangement reaction of 7-methyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-ones (I) and the alternative isomeric 7-ones (XI) has been studied. I (R=H) and XI (R=H) gave quantitatively through N–N bond cleavage methylthiouracil (III) by treating with 5% NaOH, while they yielded 4-methyl-2-thiocyanato-6(1H)pyrimidone (II) by treating with liquid ammonia. By treating I and XI (R=alkyl) with 5% NaOH, the S–C bond cleaved to produce the corresponding acylaminopyrimidine derivatives (IV and IV′) and 3-aminopyrimidinethione (V and V′). The treatment of 2-hydrazino derivative (I; R=NHNH2) with 5% NaOH gave 1-amino-2-mercapto-7-methyl-5H-s-triazolo[1,5-a]pyrimidin-5-one (VIII) through ring-opening and recyclization. On the other hand, the pyrimidine moiety of I (R=Et and i-Pr) cleaved by the action of chlorine to afford 2-amino-1,3,4-thiadiazole (X; R=Et and t-Pr).
Hydrogen Redistribution of Acetone on ZnO Catalysts
Authors: Nagai Ken-ichi , Tanaka Ken-ichi , Miyahara Koshiro
Published: July 2006

The hydrogen redistribution reaction between d0-acetone and d6-acetone was carried out at −10–60 °C over ZnO catalysts subjected to various modes of pretreatment. The activity of ZnO was several times larger than that of Zn metal, being hardly affected by the conditions of pretreatment below 350 °C and illumination with a mercury lamp. The rate of hydrogen redistribution was proportional to the amount of chemisorbed acetone which obeys the Langmuir adsorption isotherm. The activation heat of redistribution and the heat of acetone chemisorption were estimated to be 14±2 and 10±1 kcal/mol, respectively. The time course of the relative amounts of dn-acetones, independent of the catalyst or its activity, was reproducible by a calculation based on the stepwise exchange model for the hydrogen exchange of acetone. About half of the chemisorbed acetone was found to be active for the redistribution or exchange of hydrogen. From the results and IR spectrometric study of acetone adsorbed on ZnO, the hydrogen redistribution of acetone was concluded to proceed via a chemisorbed acetone with an enol type configuration on a pair of sites, Zn2+–O2−, of ZnO surface.
A Solvated Electron Formed from the Water by the Irradiation of the Recoil Particles of 10B(n,α)7Li and 6Li(n,α)T
Authors: Yokohata Akira , Tsuda Satoru
Published: July 2006

The G values of a solvated electron produced by ionizing radiation from the (n,α) activation of boron and lithium were estimated to be 0.36 (±0.06) and 0.50 (±0.05) in neutral aqueous solutions (ClCH2COOH–N2O), and 0.24 (±0.05) and 0.46 (±0.05) in alkaline aqueous solutions (K3Fe(CN)6–NaOH), respectively.
A Mössbauer Study of the Valence States of 119Sn after the EC Decay of 119Sb in Antimony and Tellurium Iodides
Authors: Ambe Fumitoshi , Ambe Shizuko
Published: July 2006

The 119Sn-Mössbauer emission spectra of 119SbI3 and 119mTeI4 sources showed the formation of Sn(II) and Sn(IV) species after the EG decay of 119Sb in the matrices.
The Reaction of Biguanides and Related Compounds. XI. The Interaction of Ethylene Carbonates with Aryl-biguanides and Related Compounds.
Authors: Furukawa Mitsuru , Yoshida Takatoshi , Hayashi Seigoro
Published: July 2006

The treatment of arylbiguanides with ethylene carbonates afforded 1-aryl-4,6-diimino-2-oxo-hexahydro-s-triazines, which were then readily converted into 1-arylisocyanuric acid by hydrolysis with concentrated hydrochloric acid.
The Syntheses of Acronycidine and 4,5,8-Trimethoxyfuro[2,3-b]quinoline
Authors: Sekiba Tetsuya
Published: July 2006

2,3-Dihydroacronycidine (VIa) was obtained from 2,3,5-trimethoxyaniline by condensation with diethyl β-benzyloxyethylmalonate, methylation, debenzylation, and then cyclodehydration. The dehydrogenation of Via gave acronycidine in relatively high yields.
Synthetic Photochemistry. V. Azulene Derivatives from the Photo-adducts of Methyl Acetopyruvate with Cycloheptatriene
Authors: Takeshita Hitoshi , Mori Akira
Published: July 2006

Two azulene derivatives, 1-methoxycarbonyl-3-methylazulene (III) and 1-methoxycarbonyl-2-methylazulene (IV), were obtained by the pyrolysis of the photoproducts of methyl acetopyruvate-cycloheptatriene. IV was understood to be derived from a subsequent photo-pinacolization of an unisolable [2+2]π photoadduct (VIII).
The Reaction of Ethyl Azidoformate with Electron Deficient Olefins and the Thermal Ring Opening of the Resulting Aziridines.
Authors: Hiyama Tamejiro , Taguchi Hiroaki , Nozaki Hitosi
Published: July 2006

Thermal or photochemical decomposition of ethyl azidoformate in mesityl oxide or in methyl crotonate afforded the corresponding aziridines. Thermal C–C bond cleavage of aziridine-1-carboxylates thus obtained is described.
Optical Resolution and Configuration of cis-β-Phenylglycidic Acid
Authors: Harada Kaoru , Nakajima Yousuke
Published: July 2006

Dl-cis-β-phenylglycidic acid was resolved using (−)-ephedrine. The configurations of α- and β-carbons of the resolved cis-(+)-glycidic acid were determined by oxydative and hydrogenolytic reactions.
Group Interactions in Polyelectrolytes. VIII. The Animation of Chloromethylated Polystyrene with Secondary Amines and the Quaternization of the Aminated Polymer
Authors: Kawabe Hiroshi
Published: July 2006

The animation of chloromethylated polystyrene (CMPS) and benzyl chloride with diethyl amine, diethanolamine, and di-n-butylamine was investigated kinetically in N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or dioxane. The apparent second-order rate constant decreased as the amination proceeded in the amination of CMPS with diethylamine and di-n-butylamine in DMF as well as in dioxane. Although a similar deceleration was also observed in the amination of CMPS with diethanolamine in DMF and DMSO, acceleration was observed during the course of the amination in dioxane. It is assumed that the deceleration and the acceleration are due to the steric obstruction and to the formation of a hydrogen bond by the neighboring groups in the transition state respectively. The intrinsic rate constants of the amination of CMPS were almost the same as those of benzyl chloride. The rate of the amination with diethanolamine was lower than that of the amination with diethylamine because of the inductive effect of the hydroxyl group. The rate constants in different solvents were in this order; DMSO>DMF>>dioxane. The aminated CMPS with diethanolamine (pK0=7.37) was quaternized with methyl iodide or bromoacetic acid in 50% aq. DMF. The deceleration due to the electrostatic effect of the neighboring groups was observed in the quaternization.
Effects of Pressure on Organic Reactions. VI. The Acid-catalyzed Rearrangement of Benzopinacol in Acetic Acid
Authors: Tamura Katsuhiro , Moriyoshi Takashi
Published: July 2006

The rates of the acid-catalyzed rearrangements of benzopinacol and of tetraphenylethylene oxide in acetic acid have been measured in the range of 35–45°C at pressures up to 983 kg/cm2. It was proved under pressures that the rearrangement of pinacol proceeds through two routes, with three processes. The probable mechanism for each process has been discussed in the light of the activation parameters, particularly the volume parameters (ΔV\eweq and ΔV). Consequently, it may be probably inferred that the classical carbonium ion is an intermediate in the rearrangement of oxide, but not in the other two processes, i.e., the conversion of pinacol to oxide and the direct rearrangement to pinacolone, and that the transition states in the two processes of rearrangement must be clearly distinguished.
The Adsorption of the Aminoethyl Derivatives of Poly(vinyl alcohol) onto Bemberg Rayon Fibers
Authors: Higuchi Mitsuo , Koyakumaru Takatoshi , Senju Ryoichi
Published: July 2006

A series of aminoethyl derivatives of poly (vinyl alcohol) was synthesized, and their adsorption behavior onto a cellulosic fiber was investigated. The results indicate that the primary factor causing adsorption is the charge interaction at the solid-liquid interface; the adsorption was suppressed as the concentration of a foreign salt (NaCl) exceeded 0.02 M, and polymers bearing no cationic group poly(vinyl alcohol) and its aminoethyi derivatives in the un-ionized state) exhibited no appreciable adsorption. The results also demonstrate that the primary variable controlling the amount of adsorption is the charge density on the polymer; the amount of adsorption increases steeply with an increase in the charge density up to a maximum, and then decreases with the increase in the charge density.
A Polarographic Investigation of the Reactions between Nitrate Ions and Chromium(II)–Cyclohexanediaminetetraacetate, Chromium(II)–Trimethylenediaminetetraacetate, and Chromium(II)–N-(2-Hydroxyethyl)ethylenediaminetriacetate Complexes
Authors: Tanaka Nobuyuki , Kano Taisaku , Ogino Hiroshi , Yamada Akifumi
Published: July 2006

Kinetic studies of the reactions between nitrate ions and Cr(II)–Y complexes, where Y represents cyclohexanediaminetetraacetic acid (CyDTA), trimethylenediaminetetraacetic acid (TRDTA), and N-(2-hydroxyethyl) ethylenediaminetriacetic acid (HEDTA), have been carried out. The reaction mechanisms of these complexes at the dropping mercury electrode were found to be expressed by the following equations:

(Remark: Graphics omitted.)

The formation constant, K, and the rate constants, k1 and k2, were determined in 0.1 M acetate buffer solutions of μ=0.5 by procedures including a curve-fitting method; the results were K=2.0×104 M−1, k1=0.55 M−1 s−1 and k2=2.8 M−1 s−1 for Cr(II)–CyDTA, K=2.4×10−5 M−1, k1=1.0×102 M−1 s−1, and k2<3 M−1 s−1 for Cr(II)–TRDTA and k1∼2×103 M−1 s−1 for Cr(II)–HEDTA.
Oxidation Activity and Acidity of V2O5–P2O5 Catalyst
Authors: Ai Mamoru , Suzuki Sadao
Published: July 2006

The oxidations of 1-butene, butadiene, and hydrogen in a large excess of air were carried out over various V–P oxide catalysts with different P2O5 contents. The oxidation activities were compared with the dehydration activity for isopropyl alcohol, which was used as a measure of the acidity of the catalysts. The surface area and the acidity per unit of surface area sharply decrease with an increase in the P2O5 content up to about 20 mol% P2O5, while with a further increase in the P2O5 they remain almost unchanged. The activity per unit of surface area for the oxidation of butene and butadiene, as well as that for the isomerization of butene, changes in the same direction as the acidity per unit of surface area. The equilibrium constant for the adsorption of olefin changes analogously. The activity per unit of surface area for the oxidation of hydrogen is not affected by the P2O5 content. The effects of the P2O5 introduced into V2O5 on the activity and selectivity are discussed from the viewpoint of the acidic nature of the catalysts.
The Radiophoto-luminescence of γ-Irradiated Hydrocarbon Glasses at 77 K
Authors: Yamazaki Hideo , Oka Koichi , Sato Masabumi , Shida Shoji
Published: July 2006

The radiophoto-luminescence (RPL) from γ-irradiated hydrocarbon glasses, i.e., 3-methylhexane, methylcyclohexane, and ethylcyclohexane, containing small amounts of various aromatics (1,3,5-trimethylbenzene, biphenyl, naphthalene, and 1,4-diazine) is investigated at 77 K by infrared-light irradiation. The spectra of the R PL consist of the fluorescence and phosphorescence of the guest aromatic molecule, and the ratio of the phosphorescence to the fluorescence intensity is larger than that in the photoexcitation, indicating the existence of another path to the triplet state. The RPL is quenched by the addition of N2O, but it is not much affected by that of NH3. A possible mechanism for the RPL is considered, and its analysis is given.
Synthesis of 1-N-[(S)-4-Amino-2-hydroxybutyryl]-3′,4′-dideoxyneamine
Authors: Takagi Yasushi , Ikeda Daishiro , Tsuchiya Tsutomu , Umezawa Sumio , Umezawa Hamao
Published: July 2006

The titled compound (5) has been prepared from 3′,4′-dideoxyneamine or ribostamycin via 1,6-cyclic carbamate intermediates (2 and 12). 3′,4′-Dideoxygenation, which is the key step in the synthesis from ribostamycin, was accomplished by the hydrogenation of 3′,4′-unsaturated derivative which was prepared from the corresponding 3′,4′-di-O-mesyl derivative by the action of sodium iodide and zinc dust in DMF. The title compound was found to have an improved antibacterial spectrum broader than 3′,4′-dideoxyneamine.
Synthesis and Photochemical Reaction of 1,5,5,9-Tetramethyl-2-decalone
Authors: Tatee Tochiro , Tsuyuki Takahiko , Aoyagi Reiko , Takahashi Takeyoshi
Published: July 2006

1,5,5,9-Tetramethyl-2-decalone (6) was synthesized from 5,5,9-trimethyl-1-decalone (7) and irradiated in n-hexane under a nitrogen atmosphere using a high pressure mercury lamp. Oxygen was passed through the reaction mixture in the dark to give a seco-nor acid, 1-carboxymethyl-2-ethyl-2,6,6-trimethylcyclohexane (8a) and a seco acid, 1-(2-carboxyethyl)-2-ethyl-2,6,6-trimethylcyclohexane (9a).
Absolute Configuration of Some Chiral Cyclopropanes
Authors: Nishiyama Kazuyoshi , Oda Jun’ichi , Inouye Yuzo
Published: July 2006

The absolute configurations of (1S : 2R)-(−)-cis-, and (1S : 2S)-(+)-trans-1-phenylcyclopropane-1,2-dicarboxylic acids, and (1S : 2R)-(−)-cis-, and (1S : 2S)-(+)-trans-1-phenyl-1,2-bis(acetoxymethyl)cyclopropanes were established by correlation to (R)-(−)-2,2-diphenylcyclopropane-1-carboxylic acid.
Phenanthro[4,5-bcd]furan Derivatives. II. A Synthesis of 3-Hydroxyphenanthro[4,5-bcd]furan (Morphenol)
Authors: Horaguchi Takaaki , Shimizu Takahachi
Published: July 2006

3-Hydroxyphenanthro[4,5-bcd]furan (I) was synthesized by the dehydrogenation, with 20% palladium on charcoal, of 3-oxo-1,2,3,8,9,9a-hexahydronaphtho[4,5-bcd]furan (XII), which had itself been prepared via a naphtho[1,8-bc]furan derivative (IX) starting from 8-hydroxy-1-tetralone (IV).
A New Technique Using the Polynomials Approximation and Trapezoidal Average Method for Estimating Kinetic Rate Constants in Systems of Linear or Nonlinear Differential Equations
Authors: Ohkubo Katsutoshi , Tsuchihashi Kohji , Sakamoto Hiroyuki
Published: July 2006

A new technique using the polynomials approximation and the trapezoidal average method, has been proposed for estimating kinetic rate constants. It is implemented by minimizing the error of the concentration (of a product) obtained from the polynomial-approximated least square-error analysis of the observed concentrations during the initial reaction stage relative to that obtained theoretically from the trapezoidal average of the calculated concentration (of a product) on the basis of the law of mass action. The technique is useful for easily and exactly estimating the rate constants in systems of linear or nonlinear differential equations. A kinetic model, A→ B\ightleftarrowsC, was used to illustrate and develop the present technique.
Reactions of Bis(acetylacetonato)palladium(II) with Triphenylphosphine and Nitrogen Bases
Authors: Baba Shigeru , Ogura Tetsuya , Kawaguchi Shinichi
Published: July 2006

Bis (acetylacetonato)palladium (II) reacts with triphenylphosphine and nitrogen bases such as pyridine, diethylamine, and N-methylbenzylamine to transform one of the chelating ligands into the carbon-bonded state. The product complexes of the type Pd(acac)2L have been isolated in high yields and characterized by IR and NMR spectra. Several reactions of Pd(acac)2PPh3 and Pd(acac)2py were also examined.
The Crystal Structure of Sodium Molybdate Dihydrate, Na2MoO4·2H2O
Authors: Matsumoto Kazuko , Kobayashi Akiko , Sasaki Yukiyoshi
Published: July 2006

Na2MoO4·2H2O is orthorhombic, with the space group of Pbca and with cell constants of a=8.463(3), b=10.552(3), and c=13.827(6) Å; U=1234.8 Å3; Z=8. The crystals are composed of alternate layers of MoO42− tetrahedra and water molecules. The layers are connected by interlinking sodium cations and hydrogen bonds. The MoO42− tetrahedron is slightly elongated in the direction of the hydrogen bonds.
Synthesis of Dialkylaminomethylenediphosphonic Acids
Authors: Fukuda Masahiro , Okamoto Yoshiki , Sakurai Hiroshi
Published: July 2006

N,N-Dialkylformamides reacted with phosphorus trichloride or phosphorus tribromide to give the corresponding dialkylaminomethylenediphosphonic acids.
The Dimerization of the Phenoselenazine and Benzo[c]-phenoselenazine Cation-radicals
Authors: Matsunaga Yoshio , Tanaka Tomio
Published: July 2006

The equilibrium constants and the heats of dimerization and the monomer and dimer spectra were determined for the phenoselenazine and benzo[c]phenoselenazine cation-radicals in aqueous sulfuric acid (1:1 by volume).
A Novel Method for the Synthesis of Cytidine Diphosphate-Choline
Authors: Kurihara Takashi , Yamamoto Isamu , Hata Tsujiaki
Published: July 2006

Cytidine diphosphate choline was synthesized by the reaction of cytidine 5′-phosphate with 2-bromoethyl 2′-(chloromethyl)-4′-nitrophenyl phosphate in the presence of trimethylamine.
Synthesis of α,β-Ethylenic Sulfones
Authors: Seshapathi M , Naidu Rao , Reddy D Bhaskar
Published: July 2006

A series of new α,β-ethylenic sulfones were prepared by the condensation of p-chlorophenylsulfonylacetic acid with various aryl aldehydes. The UV and IR spectra of all these compounds were recorded. Their IR spectra exhibited medium to strong bands in the region 1000–975 cm−1, characteristic of trans ethylenic compounds.
The Carbon-13 Nuclear Magnetic Resonance Spectra of Isomers of the Tris(l-propylenediamine)cobalt(III) Ion
Authors: Kojima Masaaki , Yamasaki Kazuo
Published: July 2006

The proton-decoupled carbon-13 NMR spectra were measured for the mer-Λ(ob), facial-Λ(ob), and facial-Δ(lel)[Co(l-pn)3]3+ ions using the Fourier transform technique. There was a clear difference between the Λ and Δ configurations. However, no appreciable difference was observed between the mer and facial isomers of Λ(ob)-[Co(l-Pn)3]3+.
The Crystal and Molecular Structure of Nagilactone A Diacetate
Authors: Hirotsu Ken , Higuchi Taiichi , Shimada Akira , Hayashi Yuji , Sakan Takeo
Published: July 2006

The title compound crystallizes in the orthorhombic space group P212121, with cell dimensions of a=10.43, b=15.45, c=13.65 Å, and Z=4. The structure was determined by direct methods from photographic data, and was refined by the least-squares method to a final R of 0.098 for 2581 reflections. Rings A and B are subject to steric strains resulting from the formation of a lactone ring. This is reflected in the abnormal values for some bond lengths, angles, and dihedral angles.
X-Ray Photoelectron Spectroscopic Studies of Catalysts — Supported Cobalt Catalysts —
Authors: Okamoto Yasuaki , Nakano Hajime , Imanaka Toshinobu , Teranishi Shiichiro
Published: July 2006

XPS techniques were used to clarify the state of supported cobalt catalysts. In order to characterize Co2+ and Co3+, the spin-orbit splitting of the 2p level, which is considered to be affected by the exchange interaction between the unpaired 3d electrons and 2p electrons, was found to be very useful. The interaction between catalyst and support was investigated. The state of supported cobalt was determined: Co2O3 on SiO2, Co2O3+ CoAl2O4 on γ-Al2O3, and LaCoO3 on La2O3. The order of the strength of the chemical interaction between cobalt and support is as follows:

La_2O_3>γ-Al_2O_3>SiO_2.

This fact was also confirmed by reduction experiments.
The Quenching of the Cadmium Resonance Radiation at 326.1 nm by Ammonia and the Emission from the Complex between Excited Cadmium Atoms and Ammonia in the Presence of Argon
Authors: Yamamoto Shunzo , Tsunashima Shigeru , Sato Shin
Published: July 2006

The pressure dependences of the emission intensities at 326.1 and 432 nm in the cadmium-photosensitized reaction of ammonia have been measured. In order to interpret the nonlinear Stern-Volmer plots for the quenching of the 326.1 nm resonance line, the following reactions have to be taken into account in the reaction scheme: Cd*+NH3\ightleftharpoonsCdNH3*V, CdNH3*V+M→CdNH3*+M. The pressure dependence of the emission from the CdNH3* complex (at 432 nm) was also well explained in terms of a reaction scheme involving the above reactions.
Kinetics and Steric Course of the Substitution of Various Olefins for the Asymmetric Olefin in trans(N,olefin)-Chloro-l-prolinato-trans-2-buteneplatinum(II)
Authors: Terai Yoshiro , Kido Hiroaki , Fujita Junnosuke , Saito Kazuo
Published: July 2006

Replacement of the coordinated trans-2-butene in trans(N,olefin)[PtCl(l-pro)(S,S-trans-2-butene)] (l-pro=l-prolinate anion) by various olefins in acetone has been studied at −20 to +23 °C. The rate is proportional to concentrations of the complex and the olefin nucleophile. No solvent path is observed. The second order rate constant k2 (10−4 to 10−1 M−1 s−1 at 8.0 °C) can be the measure of each substitution. The ΔH\eweq is around 10 kcal/mol, and ΔS\eweq ranges from −25 to −46 cal/mol K. Substitution of cis-2-butene for the asymmetrically coordinated trans-2-butene-3H gives equal k2’s on the measurement of CD strength and on that of isotopic exchange. Similar substitution of trans-2-butene gives significantly larger k2 on isotopic exchange than that on CD measurement, indicating sterically selective substitution with retention of configuration. Substitution of ethylene derivatives with various groups on the carbon atoms gives different k2’s depending on the kind of substituents. The steric interaction between the olefin nucleophile and the coordinated ligands seems to be a very important factor in determining the ease of substitution.
Sugars Containing a Carbon-phosphorus Bond. VI. 5-(Alkylphosphinyl)-5-deoxy-d-xylopyranose
Authors: Seo Kuniaki , Inokawa Saburo
Published: July 2006

The reactions of diethyl ethylphosphonite with 3-O-acetyl-5-deoxy-5-iodo-1,2-O-isorpopylidine-α-d-xylofuranose (Ia) or 3-O-benzoyl-5-deoxy-5-iodo-1,2-O-isopropylidene-α-d-xylofuranose(Ib) afforded IIa or IIc, respectively. Similarly, using diethyl butylphosphonite in place of diethyl ethylphosphonite, IIb and IId were obtained. Treatment of IIb with methanolic sodium methoxide gave 5-deoxy-1,2-O-isopropylidene-5-(methoxybutylphosphinyl)-α-d-xylofuranose together with a small amount of 5-(3-O-cyclo-butylphosphinate)-5-deoxy-1,2-O-isopropylidene-α-d-xylofuranose(VII). Compound VII was also obtained from the reaction of 5-deoxy-5-iodo-1,2-O-isopropylidene-α-d-xylofuranose(VIII) and diethyl butylphosphonite. The reaction of IIa or IIc with sodium dihydrobis(2-methoxyethoxy)aluminate gave 5-deoxy-5-(ethylphosphinyl)-1,2-O-isopropylidene-α-d-xylofuranose(IIIa). Similarly, 5-(butylphosphinyl)-5-deoxy-1,2-O-isopropylidene-α-d-xylofuranose(IIIb) was obtained from IIb, IId, VI, and VII. Hydrolysis of IIIa and IIIb with sulfuric acid gave 5-deoxy-5-(ethyl-phosphinyl)-(IVa) and 5-(butylphosphinyl)-5-deoxy-d-xylopyranose(IVb), respectively. Acetylation of IVa and IVb with acetic anhydride in pyridine gave the corresponding O-acetates Va and Vb.
Stereospecific Synthesis of Natural (+)Blastmycinone and Its Three (2R)-Diastereomers
Authors: Aburaki Shinpei , Konishi Norio , Kinoshita Mitsuhiro
Published: July 2006

Natural (+)blastmycinone [(+)1a] and its three (2R)-diastereomers [(+)1b, (−)1c, and (−)1d] were synthesized through stereospecific routes via the corresponding (−)blastmycinolactol [(−)2a] and its diastereomeric hydroxylactones [(+)2b, (−)2c, and (−)2d] from methyl 4,6-O-benzylidene-3-C-butyl-3-deoxy-α-d-altropyranoside (4) prepared by the Grignard reaction of methyl 2,3-anhydro-4,6-O-benzylidene-α-d-mannopyranoside (3) with butylmagnesium chloride. By the synthesis the relative configurations of natural type of racemic blastmycinone and its all diastereomers were completely established.
Infrared Spectra and Structure of Substituted Unsaturated Carbonyl Compounds. XIX. Four Component Conformational Equilibria in β-Ketoaldehyde Trans Enol Ethers
Authors: Dabrowski Janusz , Tencer Michal
Published: July 2006

Acylic aliphatic trans β-alkoxy-α,β-unsaturated ketones, R1COCR2=CHOR3, have been shown to exhibit restricted rotation around both the Csp2–Csp2 and Csp2–O single bonds. The conformational equilibria between the EZZ, EEZ, EZE and EEE rotamers, estimated from comparison of the IR band intensities, are dependent on the steric requirements of the alkyl substituents. The sequence of the νC=O and νC=C vibrational frequences is νC=O(s-cis/O-s-trans)>νC=O(s-cis/O-s-cis)>νC=O(s-trans/O-s-trans)>νC=O(s-trans/O-s-cis)>νc=C(s-trans/O-s-trans)>νC=O(s-trans/O-s-cis)>νC=C(s-cis/O-s-trans)>νC=C(s-cis/O-s-cis). The wave number differences ΔνC=CC=O(s-cis/O-s-trans)=75–85 cm−1, ΔνC=CC=O(s-cis/O-s-cis)=80—100 cm−1, ΔνC=CC=O(s-trans/O-s-trans)=20—30 cm−1 and ΔνC=CC=O(s-trans/O-s-cis)=35–50 cm−1.
Dielectric Relaxation and Molecular Structure. XIV. The Dielectric Behavior of Six Isomeric Pentyl Alcohols
Authors: Sato Hiroshi , Koshii Taro , Takahashi Hiroaki , Higasi Keniti
Published: July 2006

The dielectric constants and losses of six isomeric pentyl alcohols have been measured in the frequency range of 1–0.35 GHz at 25 °C. The relaxation times of these alcohols decrease with an increase in the steric hindrance of the hydroxyl group.
Abnormal Grignard Reaction of 2,4,6-Trimethylbenzophenone: An Electron-transfer Mechanism
Authors: Okubo Masao
Published: July 2006

The reaction of 2,4,6-trimethylbenzophenone with phenyl-MgBr in tetrahydrofuran was examined by ESR technique. A high amount of the ketyl radical was detected. An electron-transfer mechanism was proposed to explain the formation of o-biphenylyl mesityl ketone.
Dielectric Relaxation and Molecular Structure. XV. A Further Study of the Benzene Effect of 1,2-Dichloroethane and Related Molecules
Authors: Shiratori Naoyuki , Takahashi Hiroaki , Higasi Keniti
Published: July 2006

The dielectric relaxation times, τ, and dipole moments, μ, of 1,2-dichloroethane (A), cis-1,2-dichloroethylene(B), 1,3-dichloropropane(C), o-dichlorobenzene(D), and 1-chloro-2-propanone(E) have been measured in two aromatic and two aliphatic nonpolar solvents. The results are as follows: both the τ and μ of (A) and (E) are exceptionally large in aromatic solvents, showing the benzene effect; (B) and (C) have large τ but normal μ values in aromatic solvents, while (D) shows normal effects of the solvent upon both τ and μ in two different sets of solvents. Finally, the intetmolecular interaction between the solute and the solvent is discussed with special regard to the origin of the benzene effect.
Chemical Equilibria between a Lanthanide Shift Reagent and n-Hexylamine in Chloroform
Authors: Inagaki Fuyuhiko , Tasumi Mitsuo , Miyazawa Tatsuo
Published: July 2006

The Eu(fod)3-induced 1H NMR shifts of n-hexylamine were observed using two kinds of dilution methods. The results are analyzed in terms of the chemical equilibria among the shift reagent (L), substrate (S), 1 : 1 (LS), and 1 : 2 (LS2) complexes. The association constants and the induced shifts intrinsic to the LS and LS2 complexes are evaluated accurately by fitting the theoretical curves to the observed data. The values obtained are utilized to confirm the validity and usefulness of the extrapolation method proposed previously to determine the shift ratios for the LS complex.
The PMR Study of the cis-trans Isomerization of the Dimethylaluminum Methylphenylamide Dimer, [(CH3)2AlN(CH3)(C6H5)]2
Authors: Wakatsuki Kizuku , Tanaka Toshio
Published: July 2006

The dimethylaluminum methylphenylamide dimer exists as an equilibrium mixture of trans- (I) and cis-isomers (II) with respect to the four-membered Al2N2 skeleton, and the latter involves the magnetic non-equivalence of the Al–CH3 groups. Thermodynamic parameters for the cis to trans isomerization are obtained from the variable-temperature PMR spectra; ΔH=4.47±0.09 kj·mol−1 and ΔS=1.74±0.48 J·deg−1mol−1. The isomerization is markedly accelerated by adding 4-methylpyridine or tetrahydrofuran. A possible mechanism of the isomerization is proposed.
Combustion of Polymer Fuel-Spheres at Elevated Pressures
Authors: Saito Takeo , Iwama Akira
Published: July 2006

Two kinds of polymer spheres polyurethane (PU) and carboxyl-terminated poly butadiene (CTPB), ca. 3 and 5 mm, respectively, in diameter and used currently as fuel and/or binder constituents in solid and hybrid rocket propellants, were ignited electrically with a nichrome fiber in several oxidizing gases over the range 5–30 kg/cm2. Their combustion phenomena were studied photographically with a 16 mm movie camera. The combustion flame was observed by means of direct photographs, both the variation of diameter with time and the location of contact surface being measured with shadow photographs. It was shown that PU spheres are entirely liquefied, involving slight swelling just after ignition, and then burn in a similar manner to that of distilled hydrocarbon droplets. CTPB spheres were found to expand remarkably after ignition. At the first stage the surrounding product gases formed a diffusion flame, their apparent diameters remaining nearly constant for a short time. At the second stage the remainder of the carbonaceous substance continued to burn, turning to surface combustion. It can be predicted that in an actual rocket combustion chamber the surface of the fuel-binder for PU propellants is wet and that of GTPB propellants is covered with carbonaceous layer during the course of steady state burning. The overall mass burning rate is proportional to a half and 0.3 power of total pressure for PU and CTPB, respectively, depending slightly on the kind of inert gas for dilution of the oxidizing atmosphere in both cases. A combustion model for CTPB is presented and Compared with experimental results.
A Theory of Ion Association as a Complement of the Debye-Hückel Theory
Authors: Yokoyama Haruhiko , Yamatera Hideo
Published: July 2006

The classical Debye-Hückel theory of strong electrolyte solutions was re-examined in order to explain ion association. Regarding a symmetrical electrolyte in very dilute solutions, a more precise expression was derived for excess chemical potential due to electrostatic ion-ion interactions. This expression has, in addition to the Debye-Hückel term, a supplementary term resulting from a more proper account of the energy of the interactions of ions existing near each other. If the concept of ion association is taken as a complement of the Debye-Hückel theory, the contribution to the chemical potential of the electrolyte from ion association should correspond to the supplementary term. The following equation was thus obtained for the ion-association constant:

K=(8πNa^3/1000) \overset∞\undersetn=1∑b^2n+2/[(2n+2)! (2n-1)]

This equation is in agreement with that derived by Ebeling on the basis of the cluster theory and has an asymptotic representation (at b→∞) in common with Bjerrum’s. For practical b values, the present equation has the merit that it gives moderate K values, decreasing monotonously with an increase in the a value, and eliminates the disadvantages of Fuoss’s result, giving a minimum K value at b=3, and of Bjerrum’s, giving K=0 at ≤2.
Fluorescence Polarization of Intramolecular EDA Complexes in (9,10-Dicyanoanthracene)-(CH2)n-(Naphthalene)
Authors: Mimura Tsutomu , Itoh Michiya , Okamoto Toshihiko
Published: July 2006

Fluorescence of the intramolecular EDA complex was observed below∼140 K in the nonpolar solution of (9,10-dicyanoanthracene)-(CH2)n-(naphthalene), n=2. The fluorescence and excitation polarizations of these EDA (n=2 and 3) complexes at 77 K were determined.
Semi-empirical SCF-MO Studies of Electronic Structures of Pt-Ethylene and Pt-Acetylene Complexes
Authors: Sakaki Shigeyoshi , Kato Hiroshi , Kawamura Takashi
Published: July 2006

A parametrization in a CNDO-type MO method is presented for Pt compounds. By the use of this parametrization, the electronic spectra of PtCl42− are calculated; they agree well with the experimental spectra in transition energies and assignments. MO calculations with this parametrization are carried out on Pt(II)–ethylene, Pt(II)–acetylene, Pt(0)–ethylene, and Pt(0)–acetylene complexes. The calculated transition energies of Zeise’s salt also agree well with the experimental values. In Pt(II) complexes, electrons are donated from ethylene and acetylene to the Pt atom, while they are little donated in Pt(0) complexes. The TT-bonds of ethylene and acetylene are weaker in Pt(0) complexes than those in Pt(II) complexes. These results are the consequence of the stronger π-acceptor coordination bond in Pt(0) complexes than in Pt(II) complexes. Acetylene coordinates to the Pt atom more strongly than does ethylene. The coordination bonds of ethylene and acetylene are stronger in Pt(0) complexes than in Pt(II) complexes.
Photolysis of Cyclopropane at 1470 and 1634 Å
Authors: Shibuya Kazuhiko , Obi Kin-ichi , Tanaka Ikuzo
Published: July 2006

The vacuum-ultraviolet photolysis of cyclopropane in the gas phase has been investigated at room temperature at excitation wavelengths 1470 and 1634 Å. Primary processes are discussed in terms of variations of product yield as a function of conversion and in the presence of additives such as NO, C2D4, and H2. The relative yields of decomposition are determined at both wavelengths. The main primary process is cyclo-C3H6+hv→C2H4+CH2, the yield being 67% at 1470 Å (69% at 1634 Å). The observed product yield responsible for methylene is much less than that for ethylene. However, the yields become equal in the photolysis of cyclopropane with excess hydrogen. The other primary processes are as follows in order of decreasing importance; cyclo-C3H6+hv→C2H3+CH3, 19% (18%), cyclo-C3H6+hv→C3H4+2H, 9% (7%), cyclo-C3H6+hv→C2H2+CH3+H, 3% (4%), cyclo-C3H6+hv→C2H2+CH4, 1% (1%).
Electron Pair Concept and an Extension of the Penney-Dirac Bond Order
Authors: Okada Takashi , Fueno Takayuki
Published: July 2006

The density functions representing electron pairs are extracted from two-electron density matrices by operating irreducible tensor operators in a two-electron spin space. Properties of these functions are examined, and the generalized Penney-Dirac bond orders are defined between atomic orbitals. Significance of the bond orders in chemical valence problems is discussed.
Synthesis of (2R, 3S, 4S)-4-Amino-3-hydroxy-2-methyl-5-(3-pyridyl)pentanoic Acid Present in Antibiotic Pyridomycin
Authors: Kinoshita Mitsuhiro , Mariyama Satoshi
Published: July 2006

Natural (2R,3S,4S)-4-arnino-3-hydroxy-2-methyl-5-(3-pyridyl)pentanoic acid (1) present in antibiotic pyridomycin was synthesized. The 5,6-anhydro-1,2-O-isopropylidene-3-C-methyl-α-d-allofuranose (4) was prepared from (the known) 3-deoxy-1,2;5,6-di-O-isopropylidene-3-C-methyl-α-d-allofuranose (2). Regiospecific introduction of 3-pyridyl group to the C–6 of 4 was effected by 3-pyridyllithium. The product (5) was converted to the 5-azido derivative (7) by the SN2 substitution reaction of the 5-mesylate (6) of 5. Hydrolysis of 7 followed by two-stage oxidation with periodate-bromine in aqueous acetic acid afforded (2R,3S,4S)-4-azido-3-formyloxy-2-methyl-5-(3-pyridyl) pentanoic acid (9), which was transformed to the dihydrochloride of 1.
Studies of the π→π* Absorption Bands of 9,10-Phenanthrenequinone
Authors: Kuboyama Akira , Kobayashi Fumio , Morokuma Satomi
Published: July 2006

The π→π* S–S absorption spectra of 9,10-phenanthrenequinone and 3-bromophenanthrenequinone in solutions up to the vacuum. UV region were obtained. On the other hand, MO calculations of the π-electronic systems of these quinones were carried out by means of the P–P–P method. The π→π* absorption bands of these quinones were assigned on the basis of the calculated results. The blue-shift of the longest-wavelength π→π* band of phenanthrenequinone due to the bromine-atom substitution at its 3-position was observed. Similar facts are found in aromatic carbonyl compounds, fluorenone and acetophenone.
The Crystal and Molecular Structure of cis-2,2-Diphenyl-3,4-dichlorothietane 1,1-Dioxide
Authors: Kumakura Shigekazu
Published: July 2006

The title compound crystallizes in the space group C2⁄c with a=18.85(2), b=6.15(1), c=27.94(2) Å, β=111.3(1)°, and Z=8. The structure was determined from the photographic X-ray data and was refined by the block-diagonal least-squares method to R=0.10 for 1006 observed reflections. Centrosymmetrically related molecules in the crystal form a dimer by means of weak intermolecular C–H···O hydrogen bonds. The thietane skeleton of the compound is bent with the dihedral angle, CαSCα/CαCβCα, of 148.7°. The average distance of the C–S bonds is 1.87 Å, while that of the C–C’s in the thietane ring is 1.58 Å. The conformation of the C–Cl bonds with respect to the thietane ring is (3a4e). The transannular S···Cl distance is 3.42 Å. The CNDO/2 calculation reveals that the 3d–3p bonding overlap is present between these atoms. The bond angles involving the ring substituents deviate greatly from those observed for cis-2,2-diphenyl-3,4-dichlorothietane. These deformations may be explained in terms of dipole-dipole interactions.